index : litmus-rt.git	archive/unc-master-3.0 archived-2013.1 archived-private-master archived-semi-part demo ecrts-pgm-final ecrts14-pgm-final gpusync-rtss12 gpusync/staging linux-tip litmus2008-patch-series master pgm prop/litmus-signals prop/robust-tie-break staging test tracing-devel v2.6.34-with-arm-patches v2015.1 wip-2011.2-bbb wip-2011.2-bbb-trace wip-2012.3-gpu wip-2012.3-gpu-preport wip-2012.3-gpu-rtss13 wip-2012.3-gpu-sobliv-budget-w-kshark wip-aedzl-final wip-aedzl-revised wip-arbit-deadline wip-aux-tasks wip-bbb wip-bbb-prio-don wip-better-break wip-binary-heap wip-budget wip-color wip-color-jlh wip-d10-hz1000 wip-default-clustering wip-dissipation-jerickso wip-dissipation2-jerickso wip-ecrts14-pgm wip-edf-hsb wip-edf-os wip-edf-tie-break wip-edzl-critique wip-edzl-final wip-edzl-revised wip-events wip-extra-debug wip-fix-switch-jerickso wip-fix3 wip-fmlp-dequeue wip-ft-irq-flag wip-gpu-cleanup wip-gpu-interrupts wip-gpu-rtas12 wip-gpu-rtss12 wip-gpu-rtss12-srp wip-gpusync-merge wip-ikglp wip-k-fmlp wip-kernel-coloring wip-kernthreads wip-klmirqd-to-aux wip-kshark wip-litmus-3.2 wip-litmus2011.2 wip-litmus3.0-2011.2 wip-master-2.6.33-rt wip-mc wip-mc-bipasa wip-mc-jerickso wip-mc2-cache-slack wip-mcrit-mac wip-merge-3.0 wip-merge-v3.0 wip-migration-affinity wip-mmap-uncache wip-modechange wip-nested-locking wip-omlp-gedf wip-pai wip-percore-lib wip-performance wip-pgm wip-pgm-split wip-pm-ovd wip-prio-inh wip-prioq-dgl wip-refactored-gedf wip-release-master-fix wip-robust-tie-break wip-rt-kshark wip-rtas12-pgm wip-semi-part wip-semi-part-edfos-jerickso wip-shared-lib wip-shared-lib2 wip-shared-mem wip-splitting-jerickso wip-splitting-omlp-jerickso wip-stage-binheap wip-sun-port wip-timer-trace wip-tracepoints
	The LITMUS^RT kernel.	Bjoern Brandenburg

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Branch	Commit message	Author	Age
archive/unc-master-3.0	P-FP: fix BUG_ON releated to priority inheritance	Bjoern Brandenburg	13 years
archived-2013.1	uncachedev: mmap memory that is not cached by CPUs	Glenn Elliott	12 years
archived-private-master	Merge branch 'wip-2.6.34' into old-private-master	Andrea Bastoni	15 years
archived-semi-part	Merge branch 'wip-semi-part' of ssh://cvs/cvs/proj/litmus/repo/litmus2010 int...	Andrea Bastoni	15 years
demo	Further refinements	Jonathan Herman	14 years
ecrts-pgm-final	Merge branch 'wip-ecrts14-pgm' of ssh://rtsrv.cs.unc.edu/home/litmus/litmus-r...	Glenn Elliott	12 years
ecrts14-pgm-final	Merge branch 'wip-ecrts14-pgm' of ssh://rtsrv.cs.unc.edu/home/litmus/litmus-r...	Glenn Elliott	12 years
gpusync-rtss12	Final GPUSync implementation.	Glenn Elliott	12 years
gpusync/staging	Rename IKGLP R2DGLP.	Glenn Elliott	12 years
linux-tip	Merge branch 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/p...	Linus Torvalds	15 years
litmus2008-patch-series	add i386 feather-trace implementation	Bjoern B. Brandenburg	16 years
master	PSN-EDF: use inferred_sporadic_job_release_at	Bjoern Brandenburg	9 years
pgm	make it compile	Glenn Elliott	12 years
prop/litmus-signals	Infrastructure for Litmus signals.	Glenn Elliott	13 years
prop/robust-tie-break	Fixed bug in edf_higher_prio().	Glenn Elliott	13 years
staging	Fix tracepoint compilation error	Felipe Cerqueira	13 years
test	9/23/2016	Namhoon Kim	9 years
tracing-devel	Test kernel tracing events capabilities	Andrea Bastoni	16 years
v2.6.34-with-arm-patches	smsc911x: Add spinlocks around registers access	Catalin Marinas	15 years
v2015.1	Add ARM syscall def for get_current_budget	Bjoern Brandenburg	10 years
wip-2011.2-bbb	Litmus core: simplify np-section protocol	Bjoern B. Brandenburg	14 years
wip-2011.2-bbb-trace	Refactor sched_trace_log_message() -> debug_trace_log_message()	Andrea Bastoni	14 years
wip-2012.3-gpu	SOBLIV draining support for C-EDF.	Glenn Elliott	12 years
wip-2012.3-gpu-preport	pick up last C-RM file	Glenn Elliott	12 years
wip-2012.3-gpu-rtss13	Fix critical bug in GPU tracker.	Glenn Elliott	12 years
wip-2012.3-gpu-sobliv-budget-w-kshark	Proper sobliv draining and many bug fixes.	Glenn Elliott	12 years
wip-aedzl-final	Make it easier to compile AEDZL interfaces in liblitmus.	Glenn Elliott	15 years
wip-aedzl-revised	Add sched_trace data for Apative EDZL	Glenn Elliott	15 years
wip-arbit-deadline	Fix compilation bug.	Glenn Elliott	13 years
wip-aux-tasks	Description of refined aux task inheritance.	Glenn Elliott	13 years
wip-bbb	GSN-EDF & Core: improve debug TRACE'ing for NP sections	Bjoern B. Brandenburg	14 years
wip-bbb-prio-don	use correct timestamp	Bjoern B. Brandenburg	14 years
wip-better-break	Implement hash-based EDF tie-breaking.	Glenn Elliott	13 years
wip-binary-heap	Make C-EDF work with simplified binheap_delete	Glenn Elliott	13 years
wip-budget	Added support for choices in budget policy enforcement.	Glenn Elliott	15 years
wip-color	Summarize schedulability with final record	Jonathan Herman	13 years
wip-color-jlh	sched_color: Fixed two bugs causing crashing on experiment restart and a rare...	Jonathan Herman	13 years
wip-d10-hz1000	Enable HZ=1000 on District 10	Bjoern B. Brandenburg	15 years
wip-default-clustering	Feature: Make default C-EDF clustering compile-time configurable.	Glenn Elliott	15 years
wip-dissipation-jerickso	Update from 2.6.36 to 2.6.36.4	Jeremy Erickson	11 years
wip-dissipation2-jerickso	Update 2.6.36 to 2.6.36.4	Jeremy Erickson	11 years
wip-ecrts14-pgm	Merge branch 'wip-ecrts14-pgm' of ssh://rtsrv.cs.unc.edu/home/litmus/litmus-r...	Glenn Elliott	12 years
wip-edf-hsb	last tested version	Jonathan Herman	14 years
wip-edf-os	Lookup table EDF-os	Jeremy Erickson	12 years
wip-edf-tie-break	Merge branch 'wip-edf-tie-break' of ssh://rtsrv.cs.unc.edu/home/litmus/litmus...	Glenn Elliott	13 years
wip-edzl-critique	Use hr_timer's active checks instead of having own flag.	Glenn Elliott	15 years
wip-edzl-final	Implementation of the EDZL scheduler.	Glenn Elliott	15 years
wip-edzl-revised	Clean up comments.	Glenn Elliott	15 years
wip-events	Added support for tracing arbitrary actions.	Jonathan Herman	15 years
wip-extra-debug	DBG: add additional tracing	Bjoern B. Brandenburg	15 years
wip-fix-switch-jerickso	Attempt to fix race condition with plugin switching	Jeremy Erickson	15 years
wip-fix3	sched: show length of runqueue clock deactivation in /proc/sched_debug	Bjoern B. Brandenburg	15 years
wip-fmlp-dequeue	Improve FMLP queue management.	Glenn Elliott	14 years
wip-ft-irq-flag	Feather-Trace: keep track of interrupt-related interference.	Bjoern B. Brandenburg	14 years
wip-gpu-cleanup	Enable sched_trace log injection from userspace	Glenn Elliott	13 years
wip-gpu-interrupts	Remove option for threading of all softirqs.	Glenn Elliott	14 years
wip-gpu-rtas12	Generalized GPU cost predictors + EWMA. (untested)	Glenn Elliott	13 years
wip-gpu-rtss12	Final GPUSync implementation.	Glenn Elliott	13 years
wip-gpu-rtss12-srp	experimental changes to support GPUs under SRP	Glenn Elliott	13 years
wip-gpusync-merge	Cleanup priority tracking for budget enforcement.	Glenn Elliott	12 years
wip-ikglp	Move RSM and IKGLP imp. to own .c files	Glenn Elliott	13 years
wip-k-fmlp	Merge branch 'mpi-master' into wip-k-fmlp	Glenn Elliott	14 years
wip-kernel-coloring	Added recolor syscall	Namhoon Kim	7 years
wip-kernthreads	Kludge work-queue processing into klitirqd.	Glenn Elliott	15 years
wip-klmirqd-to-aux	Allow klmirqd threads to be given names.	Glenn Elliott	13 years
wip-kshark	Merge branch 'mpi-staging' into wip-kshark	Jonathan Herman	13 years
wip-litmus-3.2	Merge commit 'v3.2' into litmus-staging	Andrea Bastoni	13 years
wip-litmus2011.2	Cleanup: Coding conformance for affinity stuff.	Glenn Elliott	14 years
wip-litmus3.0-2011.2	Feather-Trace: keep track of interrupt-related interference.	Bjoern B. Brandenburg	14 years
wip-master-2.6.33-rt	Avoid deadlock when switching task policy to BACKGROUND (ugly)	Andrea Bastoni	15 years
wip-mc	Removed ARM-specific hacks which disabled less common mixed-criticality featu...	Jonathan Herman	12 years
wip-mc-bipasa	MC-EDF added	bipasa chattopadhyay	13 years
wip-mc-jerickso	Split C/D queues	Jeremy Erickson	15 years
wip-mc2-cache-slack	Manually patched mc^2 related code	Ming Yang	10 years
wip-mcrit-mac	cosmetic	Mac Mollison	15 years
wip-merge-3.0	Prevent Linux to send IPI and queue tasks on remote CPUs.	Andrea Bastoni	14 years
wip-merge-v3.0	Prevent Linux to send IPI and queue tasks on remote CPUs.	Andrea Bastoni	14 years
wip-migration-affinity	NULL affinity dereference in C-EDF.	Glenn Elliott	14 years
wip-mmap-uncache	share branch with others	Glenn Elliott	13 years
wip-modechange	RTSS 2017 submission	Namhoon Kim	8 years
wip-nested-locking	Appears to be working.	Bryan Ward	12 years
wip-omlp-gedf	First implementation of G-OMLP.	Glenn Elliott	15 years
wip-pai	Some cleanup of PAI	Glenn Elliott	14 years
wip-percore-lib	9/21/2016	Namhoon Kim	9 years
wip-performance	CONFIG_DONT_PREEMPT_ON_TIE: Don't preeempt a scheduled task on priority tie.	Glenn Elliott	14 years
wip-pgm	Add PGM support to C-FL	Glenn Elliott	12 years
wip-pgm-split	First draft of C-FL-split	Namhoon Kim	12 years
wip-pm-ovd	Add preemption-and-migration overhead tracing support	Andrea Bastoni	15 years
wip-prio-inh	P-EDF updated to use the generic pi framework.	Glenn Elliott	15 years
wip-prioq-dgl	BUG FIX: Support DGLs with PRIOQ_MUTEX	Glenn Elliott	13 years
wip-refactored-gedf	Generalizd architecture for GEDF-style scheduelrs to reduce code redundancy.	Glenn Elliott	15 years
wip-release-master-fix	bugfix: release master CPU must signal task was picked	Bjoern B. Brandenburg	14 years
wip-robust-tie-break	EDF priority tie-breaks.	Glenn Elliott	13 years
wip-rt-kshark	Move task time accounting into the complete_job method.	Jonathan Herman	13 years
wip-rtas12-pgm	Scheduling of PGM jobs.	Glenn Elliott	13 years
wip-semi-part	Fix compile error with newer GCC	Jeremy Erickson	12 years
wip-semi-part-edfos-jerickso	Use initial CPU set by client	Jeremy Erickson	12 years
wip-shared-lib	TODO: Fix condition checks in replicate_page_move_mapping()	Namhoon Kim	9 years
wip-shared-lib2	RTAS 2017 Submission ver.	Namhoon Kim	9 years
wip-shared-mem	Initial commit for shared library	Namhoon Kim	9 years
wip-splitting-jerickso	Fix release behavior	Jeremy Erickson	13 years
wip-splitting-omlp-jerickso	Bjoern's Dissertation Code with Priority Donation	Jeremy Erickson	13 years
wip-stage-binheap	An efficient binary heap implementation.	Glenn Elliott	13 years
wip-sun-port	Dynamic memory allocation and clean exit for FeatherTrace	Christopher Kenna	15 years
wip-timer-trace	bugfix: C-EDF, clear scheduled field of the correct CPU upon task_exit	Andrea Bastoni	15 years
wip-tracepoints	Add kernel-style events for sched_trace_XXX() functions	Andrea Bastoni	14 years
Tag	Download	Author	Age
2015.1	commit 8e51b37822...	Bjoern Brandenburg	10 years
2013.1	commit bcaacec1ca...	Glenn Elliott	12 years
2012.3	commit c158b5fbe4...	Jonathan Herman	13 years
2012.2	commit b53c479a0f...	Glenn Elliott	13 years
2012.1	commit 83b11ea1c6...	Bjoern B. Brandenburg	14 years
rtas12-mc-beta-exp	commit 8e236ee20f...	Christopher Kenna	14 years
2011.1	commit d11808b5c6...	Christopher Kenna	15 years
v2.6.37-rc4	commit e8a7e48bb2...	Linus Torvalds	15 years
v2.6.37-rc3	commit 3561d43fd2...	Linus Torvalds	15 years
v2.6.37-rc2	commit e53beacd23...	Linus Torvalds	15 years
v2.6.37-rc1	commit c8ddb2713c...	Linus Torvalds	15 years
v2.6.36	commit f6f94e2ab1...	Linus Torvalds	15 years
2010.2	commit 5c5456402d...	Bjoern B. Brandenburg	15 years
v2.6.36-rc8	commit cd07202cc8...	Linus Torvalds	15 years
v2.6.36-rc7	commit cb655d0f3d...	Linus Torvalds	15 years
v2.6.36-rc6	commit 899611ee7d...	Linus Torvalds	15 years
v2.6.36-rc5	commit b30a3f6257...	Linus Torvalds	15 years
v2.6.36-rc4	commit 49553c2ef8...	Linus Torvalds	15 years
v2.6.36-rc3	commit 2bfc96a127...	Linus Torvalds	15 years
v2.6.36-rc2	commit 76be97c1fc...	Linus Torvalds	15 years
v2.6.36-rc1	commit da5cabf80e...	Linus Torvalds	15 years
v2.6.35	commit 9fe6206f40...	Linus Torvalds	15 years
v2.6.35-rc6	commit b37fa16e78...	Linus Torvalds	15 years
v2.6.35-rc5	commit 1c5474a65b...	Linus Torvalds	15 years
v2.6.35-rc4	commit 815c4163b6...	Linus Torvalds	15 years
v2.6.35-rc3	commit 7e27d6e778...	Linus Torvalds	15 years
v2.6.35-rc2	commit e44a21b726...	Linus Torvalds	15 years
v2.6.35-rc1	commit 67a3e12b05...	Linus Torvalds	15 years
2010.1	commit 7c1ff4c544...	Andrea Bastoni	15 years
v2.6.34	commit e40152ee1e...	Linus Torvalds	15 years
v2.6.33.4	commit 4640b4e7d9...	Greg Kroah-Hartman	15 years
v2.6.34-rc7	commit b57f95a382...	Linus Torvalds	15 years
v2.6.34-rc6	commit 66f41d4c5c...	Linus Torvalds	15 years
v2.6.33.3	commit 3e7ad8ed97...	Greg Kroah-Hartman	15 years
v2.6.34-rc5	commit 01bf0b6457...	Linus Torvalds	15 years
v2.6.34-rc4	commit 0d0fb0f9c5...	Linus Torvalds	15 years
v2.6.33.2	commit 19f00f070c...	Greg Kroah-Hartman	15 years
v2.6.34-rc3	commit 2eaa9cfdf3...	Linus Torvalds	15 years
v2.6.34-rc2	commit 220bf991b0...	Linus Torvalds	16 years
v2.6.33.1	commit dbdafe5ccf...	Greg Kroah-Hartman	16 years
v2.6.34-rc1	commit 57d54889cd...	Linus Torvalds	16 years
v2.6.33	commit 60b341b778...	Linus Torvalds	16 years
v2.6.33-rc8	commit 724e6d3fe8...	Linus Torvalds	16 years
v2.6.33-rc7	commit 29275254ca...	Linus Torvalds	16 years
v2.6.33-rc6	commit abe94c756c...	Linus Torvalds	16 years
v2.6.33-rc5	commit 92dcffb916...	Linus Torvalds	16 years
v2.6.33-rc4	commit 7284ce6c9f...	Linus Torvalds	16 years
v2.6.33-rc3	commit 74d2e4f8d7...	Linus Torvalds	16 years
v2.6.33-rc2	commit 6b7b284958...	Linus Torvalds	16 years
v2.6.33-rc1	commit 55639353a0...	Linus Torvalds	16 years
v2.6.32	commit 22763c5cf3...	Linus Torvalds	16 years
v2.6.32-rc8	commit 648f4e3e50...	Linus Torvalds	16 years
v2.6.32-rc7	commit 156171c71a...	Linus Torvalds	16 years
v2.6.32-rc6	commit b419148e56...	Linus Torvalds	16 years
v2.6.32-rc5	commit 012abeea66...	Linus Torvalds	16 years
v2.6.32-rc4	commit 161291396e...	Linus Torvalds	16 years
v2.6.32-rc3	commit 374576a8b6...	Linus Torvalds	16 years
v2.6.32-rc1	commit 17d857be64...	Linus Torvalds	16 years
v2.6.32-rc2	commit 17d857be64...	Linus Torvalds	16 years
v2.6.31	commit 74fca6a428...	Linus Torvalds	16 years
v2.6.31-rc9	commit e07cccf404...	Linus Torvalds	16 years
v2.6.31-rc8	commit 326ba5010a...	Linus Torvalds	16 years
v2.6.31-rc7	commit 422bef879e...	Linus Torvalds	16 years
v2.6.31-rc6	commit 64f1607ffb...	Linus Torvalds	16 years
v2.6.31-rc5	commit ed680c4ad4...	Linus Torvalds	16 years
v2.6.31-rc4	commit 4be3bd7849...	Linus Torvalds	16 years
v2.6.31-rc3	commit 6847e154e3...	Linus Torvalds	16 years
v2.6.31-rc2	commit 8e4a718ff3...	Linus Torvalds	16 years
v2.6.31-rc1	commit 28d0325ce6...	Linus Torvalds	16 years
v2.6.30	commit 07a2039b8e...	Linus Torvalds	16 years
v2.6.30-rc8	commit 9fa7eb283c...	Linus Torvalds	16 years
v2.6.30-rc7	commit 59a3759d0f...	Linus Torvalds	16 years
v2.6.30-rc6	commit 1406de8e11...	Linus Torvalds	16 years
v2.6.30-rc5	commit 091bf7624d...	Linus Torvalds	16 years
v2.6.30-rc4	commit 091438dd56...	Linus Torvalds	16 years
v2.6.30-rc3	commit 0910697403...	Linus Torvalds	16 years
v2.6.30-rc2	commit 0882e8dd3a...	Linus Torvalds	16 years
v2.6.30-rc1	commit 577c9c456f...	Linus Torvalds	16 years
v2.6.29	commit 8e0ee43bc2...	Linus Torvalds	16 years
v2.6.29-rc8	commit 041b62374c...	Linus Torvalds	17 years
v2.6.29-rc7	commit fec6c6fec3...	Linus Torvalds	17 years
v2.6.29-rc6	commit 20f4d6c3a2...	Linus Torvalds	17 years
v2.6.29-rc5	commit d2f8d7ee1a...	Linus Torvalds	17 years
v2.6.29-rc4	commit 8e4921515c...	Linus Torvalds	17 years
v2.6.29-rc3	commit 18e352e4a7...	Linus Torvalds	17 years
v2.6.29-rc2	commit 1de9e8e70f...	Linus Torvalds	17 years
v2.6.29-rc1	commit c59765042f...	Linus Torvalds	17 years
v2.6.28	commit 4a6908a3a0...	Linus Torvalds	17 years
v2.6.28-rc9	commit 929096fe9f...	Linus Torvalds	17 years
v2.6.28-rc8	commit 8b1fae4e42...	Linus Torvalds	17 years
v2.6.28-rc7	commit 061e41fdb5...	Linus Torvalds	17 years
v2.6.28-rc6	commit 13d428afc0...	Linus Torvalds	17 years
v2.6.28-rc5	commit 9bf1a2445f...	Linus Torvalds	17 years
v2.6.28-rc4	commit f7160c7573...	Linus Torvalds	17 years
v2.6.28-rc3	commit 45beca08dd...	Linus Torvalds	17 years
v2.6.28-rc2	commit 0173a3265b...	Linus Torvalds	17 years
v2.6.28-rc1	commit 57f8f7b60d...	Linus Torvalds	17 years
v2.6.27	commit 3fa8749e58...	Linus Torvalds	17 years
v2.6.27-rc9	commit 4330ed8ed4...	Linus Torvalds	17 years
v2.6.27-rc8	commit 94aca1dac6...	Linus Torvalds	17 years
v2.6.27-rc7	commit 72d31053f6...	Linus Torvalds	17 years
v2.6.27-rc6	commit adee14b2e1...	Linus Torvalds	17 years
v2.6.27-rc5	commit 24342c34a0...	Linus Torvalds	17 years
v2.6.27-rc4	commit 6a55617ed5...	Linus Torvalds	17 years
v2.6.27-rc3	commit 30a2f3c60a...	Linus Torvalds	17 years
v2.6.27-rc2	commit 0967d61ea0...	Linus Torvalds	17 years
v2.6.27-rc1	commit 6e86841d05...	Linus Torvalds	17 years
v2.6.26	commit bce7f793da...	Linus Torvalds	17 years
v2.6.26-rc9	commit b7279469d6...	Linus Torvalds	17 years
v2.6.26-rc8	commit 543cf4cb3f...	Linus Torvalds	17 years
v2.6.26-rc7	commit d70ac829b7...	Linus Torvalds	17 years
v2.6.26-rc6	commit 5dd34572ad...	Linus Torvalds	17 years
v2.6.26-rc5	commit 53c8ba9540...	Linus Torvalds	17 years
v2.6.26-rc4	commit e490517a03...	Linus Torvalds	17 years
v2.6.26-rc3	commit b8291ad07a...	Linus Torvalds	17 years
v2.6.26-rc2	commit 492c2e476e...	Linus Torvalds	17 years
v2.6.26-rc1	commit 2ddcca36c8...	Linus Torvalds	17 years
v2.6.25	commit 4b119e21d0...	Linus Torvalds	17 years
v2.6.25-rc9	commit 120dd64cac...	Linus Torvalds	17 years
v2.6.25-rc8	commit 0e81a8ae37...	Linus Torvalds	17 years
v2.6.25-rc7	commit 05dda977f2...	Linus Torvalds	17 years
v2.6.25-rc6	commit a978b30af3...	Linus Torvalds	18 years
v2.6.25-rc5	commit cdeeeae056...	Linus Torvalds	18 years
v2.6.25-rc4	commit 29e8c3c304...	Linus Torvalds	18 years
v2.6.25-rc3	commit bfa274e243...	Linus Torvalds	18 years
v2.6.25-rc2	commit 101142c37b...	Linus Torvalds	18 years
v2.6.25-rc1	commit 19af35546d...	Linus Torvalds	18 years
v2.6.24	commit 49914084e7...	Linus Torvalds	18 years
v2.6.24-rc8	commit cbd9c88369...	Linus Torvalds	18 years
v2.6.24-rc7	commit 3ce5445046...	Linus Torvalds	18 years
v2.6.24-rc6	commit ea67db4cdb...	Linus Torvalds	18 years
v2.6.24-rc5	commit 82d29bf6dc...	Linus Torvalds	18 years
v2.6.24-rc4	commit 09b56adc98...	Linus Torvalds	18 years
v2.6.24-rc3	commit d9f8bcbf67...	Linus Torvalds	18 years
v2.6.24-rc2	commit dbeeb816e8...	Linus Torvalds	18 years
v2.6.24-rc1	commit c9927c2bf4...	Linus Torvalds	18 years
v2.6.23	commit bbf25010f1...	Linus Torvalds	18 years
v2.6.23-rc9	commit 3146b39c18...	Linus Torvalds	18 years
v2.6.23-rc8	commit 4942de4a0e...	Linus Torvalds	18 years
v2.6.23-rc7	commit 81cfe79b9c...	Linus Torvalds	18 years
v2.6.23-rc6	commit 0d4cbb5e7f...	Linus Torvalds	18 years
v2.6.23-rc5	commit 40ffbfad6b...	Linus Torvalds	18 years
v2.6.23-rc4	commit b07d68b5ca...	Linus Torvalds	18 years
v2.6.23-rc3	commit 39d3520c92...	Linus Torvalds	18 years
v2.6.23-rc2	commit d4ac2477fa...	Linus Torvalds	18 years
v2.6.23-rc1	commit f695baf2df...	Linus Torvalds	18 years
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generated by cgit v1.2.2 (git 2.25.0) at 2025-09-15 15:33:23 -0400

/*
 * Completely Fair Scheduling (CFS) Class (SCHED_NORMAL/SCHED_BATCH)
 *
 *  Copyright (C) 2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 *
 *  Interactivity improvements by Mike Galbraith
 *  (C) 2007 Mike Galbraith <efault@gmx.de>
 *
 *  Various enhancements by Dmitry Adamushko.
 *  (C) 2007 Dmitry Adamushko <dmitry.adamushko@gmail.com>
 *
 *  Group scheduling enhancements by Srivatsa Vaddagiri
 *  Copyright IBM Corporation, 2007
 *  Author: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
 *
 *  Scaled math optimizations by Thomas Gleixner
 *  Copyright (C) 2007, Thomas Gleixner <tglx@linutronix.de>
 *
 *  Adaptive scheduling granularity, math enhancements by Peter Zijlstra
 *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
 */

#include <linux/latencytop.h>
#include <linux/sched.h>
#include <linux/cpumask.h>
#include <linux/slab.h>
#include <linux/profile.h>
#include <linux/interrupt.h>

#include <trace/events/sched.h>

#include "sched.h"

/*
 * Targeted preemption latency for CPU-bound tasks:
 * (default: 6ms * (1 + ilog(ncpus)), units: nanoseconds)
 *
 * NOTE: this latency value is not the same as the concept of
 * 'timeslice length' - timeslices in CFS are of variable length
 * and have no persistent notion like in traditional, time-slice
 * based scheduling concepts.
 *
 * (to see the precise effective timeslice length of your workload,
 *  run vmstat and monitor the context-switches (cs) field)
 */
unsigned int sysctl_sched_latency = 6000000ULL;
unsigned int normalized_sysctl_sched_latency = 6000000ULL;

/*
 * The initial- and re-scaling of tunables is configurable
 * (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus))
 *
 * Options are:
 * SCHED_TUNABLESCALING_NONE - unscaled, always *1
 * SCHED_TUNABLESCALING_LOG - scaled logarithmical, *1+ilog(ncpus)
 * SCHED_TUNABLESCALING_LINEAR - scaled linear, *ncpus
 */
enum sched_tunable_scaling sysctl_sched_tunable_scaling
	= SCHED_TUNABLESCALING_LOG;

/*
 * Minimal preemption granularity for CPU-bound tasks:
 * (default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds)
 */
unsigned int sysctl_sched_min_granularity = 750000ULL;
unsigned int normalized_sysctl_sched_min_granularity = 750000ULL;

/*
 * is kept at sysctl_sched_latency / sysctl_sched_min_granularity
 */
static unsigned int sched_nr_latency = 8;

/*
 * After fork, child runs first. If set to 0 (default) then
 * parent will (try to) run first.
 */
unsigned int sysctl_sched_child_runs_first __read_mostly;

/*
 * SCHED_OTHER wake-up granularity.
 * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
 *
 * This option delays the preemption effects of decoupled workloads
 * and reduces their over-scheduling. Synchronous workloads will still
 * have immediate wakeup/sleep latencies.
 */
unsigned int sysctl_sched_wakeup_granularity = 1000000UL;
unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL;

const_debug unsigned int sysctl_sched_migration_cost = 500000UL;

/*
 * The exponential sliding  window over which load is averaged for shares
 * distribution.
 * (default: 10msec)
 */
unsigned int __read_mostly sysctl_sched_shares_window = 10000000UL;

#ifdef CONFIG_CFS_BANDWIDTH
/*
 * Amount of runtime to allocate from global (tg) to local (per-cfs_rq) pool
 * each time a cfs_rq requests quota.
 *
 * Note: in the case that the slice exceeds the runtime remaining (either due
 * to consumption or the quota being specified to be smaller than the slice)
 * we will always only issue the remaining available time.
 *
 * default: 5 msec, units: microseconds
  */
unsigned int sysctl_sched_cfs_bandwidth_slice = 5000UL;
#endif

/*
 * Increase the granularity value when there are more CPUs,
 * because with more CPUs the 'effective latency' as visible
 * to users decreases. But the relationship is not linear,
 * so pick a second-best guess by going with the log2 of the
 * number of CPUs.
 *
 * This idea comes from the SD scheduler of Con Kolivas:
 */
static int get_update_sysctl_factor(void)
{
	unsigned int cpus = min_t(int, num_online_cpus(), 8);
	unsigned int factor;

	switch (sysctl_sched_tunable_scaling) {
	case SCHED_TUNABLESCALING_NONE:
		factor = 1;
		break;
	case SCHED_TUNABLESCALING_LINEAR:
		factor = cpus;
		break;
	case SCHED_TUNABLESCALING_LOG:
	default:
		factor = 1 + ilog2(cpus);
		break;
	}

	return factor;
}

static void update_sysctl(void)
{
	unsigned int factor = get_update_sysctl_factor();

#define SET_SYSCTL(name) \
	(sysctl_##name = (factor) * normalized_sysctl_##name)
	SET_SYSCTL(sched_min_granularity);
	SET_SYSCTL(sched_latency);
	SET_SYSCTL(sched_wakeup_granularity);
#undef SET_SYSCTL
}

void sched_init_granularity(void)
{
	update_sysctl();
}

#if BITS_PER_LONG == 32
# define WMULT_CONST	(~0UL)
#else
# define WMULT_CONST	(1UL << 32)
#endif

#define WMULT_SHIFT	32

/*
 * Shift right and round:
 */
#define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y))

/*
 * delta *= weight / lw
 */
static unsigned long
calc_delta_mine(unsigned long delta_exec, unsigned long weight,
		struct load_weight *lw)
{
	u64 tmp;

	/*
	 * weight can be less than 2^SCHED_LOAD_RESOLUTION for task group sched
	 * entities since MIN_SHARES = 2. Treat weight as 1 if less than
	 * 2^SCHED_LOAD_RESOLUTION.
	 */
	if (likely(weight > (1UL << SCHED_LOAD_RESOLUTION)))
		tmp = (u64)delta_exec * scale_load_down(weight);
	else
		tmp = (u64)delta_exec;

	if (!lw->inv_weight) {
		unsigned long w = scale_load_down(lw->weight);

		if (BITS_PER_LONG > 32 && unlikely(w >= WMULT_CONST))
			lw->inv_weight = 1;
		else if (unlikely(!w))
			lw->inv_weight = WMULT_CONST;
		else
			lw->inv_weight = WMULT_CONST / w;
	}

	/*
	 * Check whether we'd overflow the 64-bit multiplication:
	 */
	if (unlikely(tmp > WMULT_CONST))
		tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight,
			WMULT_SHIFT/2);
	else
		tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT);

	return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX);
}


const struct sched_class fair_sched_class;

/**************************************************************
 * CFS operations on generic schedulable entities:
 */

#ifdef CONFIG_FAIR_GROUP_SCHED

/* cpu runqueue to which this cfs_rq is attached */
static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
{
	return cfs_rq->rq;
}

/* An entity is a task if it doesn't "own" a runqueue */
#define entity_is_task(se)	(!se->my_q)

static inline struct task_struct *task_of(struct sched_entity *se)
{
#ifdef CONFIG_SCHED_DEBUG
	WARN_ON_ONCE(!entity_is_task(se));
#endif
	return container_of(se, struct task_struct, se);
}

/* Walk up scheduling entities hierarchy */
#define for_each_sched_entity(se) \
		for (; se; se = se->parent)

static inline struct cfs_rq *task_cfs_rq(struct task_struct *p)
{
	return p->se.cfs_rq;
}

/* runqueue on which this entity is (to be) queued */
static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se)
{
	return se->cfs_rq;
}

/* runqueue "owned" by this group */
static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp)
{
	return grp->my_q;
}

static inline void list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq)
{
	if (!cfs_rq->on_list) {
		/*
		 * Ensure we either appear before our parent (if already
		 * enqueued) or force our parent to appear after us when it is
		 * enqueued.  The fact that we always enqueue bottom-up
		 * reduces this to two cases.
		 */
		if (cfs_rq->tg->parent &&
		    cfs_rq->tg->parent->cfs_rq[cpu_of(rq_of(cfs_rq))]->on_list) {
			list_add_rcu(&cfs_rq->leaf_cfs_rq_list,
				&rq_of(cfs_rq)->leaf_cfs_rq_list);
		} else {
			list_add_tail_rcu(&cfs_rq->leaf_cfs_rq_list,
				&rq_of(cfs_rq)->leaf_cfs_rq_list);
		}

		cfs_rq->on_list = 1;
	}
}

static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
{
	if (cfs_rq->on_list) {
		list_del_rcu(&cfs_rq->leaf_cfs_rq_list);
		cfs_rq->on_list = 0;
	}
}

/* Iterate thr' all leaf cfs_rq's on a runqueue */
#define for_each_leaf_cfs_rq(rq, cfs_rq) \
	list_for_each_entry_rcu(cfs_rq, &rq->leaf_cfs_rq_list, leaf_cfs_rq_list)

/* Do the two (enqueued) entities belong to the same group ? */
static inline int
is_same_group(struct sched_entity *se, struct sched_entity *pse)
{
	if (se->cfs_rq == pse->cfs_rq)
		return 1;

	return 0;
}

static inline struct sched_entity *parent_entity(struct sched_entity *se)
{
	return se->parent;
}

/* return depth at which a sched entity is present in the hierarchy */
static inline int depth_se(struct sched_entity *se)
{
	int depth = 0;

	for_each_sched_entity(se)
		depth++;

	return depth;
}

static void
find_matching_se(struct sched_entity **se, struct sched_entity **pse)
{
	int se_depth, pse_depth;

	/*
	 * preemption test can be made between sibling entities who are in the
	 * same cfs_rq i.e who have a common parent. Walk up the hierarchy of
	 * both tasks until we find their ancestors who are siblings of common
	 * parent.
	 */

	/* First walk up until both entities are at same depth */
	se_depth = depth_se(*se);
	pse_depth = depth_se(*pse);

	while (se_depth > pse_depth) {
		se_depth--;
		*se = parent_entity(*se);
	}

	while (pse_depth > se_depth) {
		pse_depth--;
		*pse = parent_entity(*pse);
	}

	while (!is_same_group(*se, *pse)) {
		*se = parent_entity(*se);
		*pse = parent_entity(*pse);
	}
}

#else	/* !CONFIG_FAIR_GROUP_SCHED */

static inline struct task_struct *task_of(struct sched_entity *se)
{
	return container_of(se, struct task_struct, se);
}

static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
{
	return container_of(cfs_rq, struct rq, cfs);
}

#define entity_is_task(se)	1

#define for_each_sched_entity(se) \
		for (; se; se = NULL)

static inline struct cfs_rq *task_cfs_rq(struct task_struct *p)
{
	return &task_rq(p)->cfs;
}

static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se)
{
	struct task_struct *p = task_of(se);
	struct rq *rq = task_rq(p);

	return &rq->cfs;
}

/* runqueue "owned" by this group */
static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp)
{
	return NULL;
}

static inline void list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq)
{
}

static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
{
}

#define for_each_leaf_cfs_rq(rq, cfs_rq) \
		for (cfs_rq = &rq->cfs; cfs_rq; cfs_rq = NULL)

static inline int
is_same_group(struct sched_entity *se, struct sched_entity *pse)
{
	return 1;
}

static inline struct sched_entity *parent_entity(struct sched_entity *se)
{
	return NULL;
}

static inline void
find_matching_se(struct sched_entity **se, struct sched_entity **pse)
{
}

#endif	/* CONFIG_FAIR_GROUP_SCHED */

static __always_inline
void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, unsigned long delta_exec);

/**************************************************************
 * Scheduling class tree data structure manipulation methods:
 */

static inline u64 max_vruntime(u64 min_vruntime, u64 vruntime)
{
	s64 delta = (s64)(vruntime - min_vruntime);
	if (delta > 0)
		min_vruntime = vruntime;

	return min_vruntime;
}

static inline u64 min_vruntime(u64 min_vruntime, u64 vruntime)
{
	s64 delta = (s64)(vruntime - min_vruntime);
	if (delta < 0)
		min_vruntime = vruntime;

	return min_vruntime;
}

static inline int entity_before(struct sched_entity *a,
				struct sched_entity *b)
{
	return (s64)(a->vruntime - b->vruntime) < 0;
}

static void update_min_vruntime(struct cfs_rq *cfs_rq)
{
	u64 vruntime = cfs_rq->min_vruntime;

	if (cfs_rq->curr)
		vruntime = cfs_rq->curr->vruntime;

	if (cfs_rq->rb_leftmost) {
		struct sched_entity *se = rb_entry(cfs_rq->rb_leftmost,
						   struct sched_entity,
						   run_node);

		if (!cfs_rq->curr)
			vruntime = se->vruntime;
		else
			vruntime = min_vruntime(vruntime, se->vruntime);
	}

	cfs_rq->min_vruntime = max_vruntime(cfs_rq->min_vruntime, vruntime);
#ifndef CONFIG_64BIT
	smp_wmb();
	cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime;
#endif
}

/*
 * Enqueue an entity into the rb-tree:
 */
static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
	struct rb_node **link = &cfs_rq->tasks_timeline.rb_node;
	struct rb_node *parent = NULL;
	struct sched_entity *entry;
	int leftmost = 1;

	/*
	 * Find the right place in the rbtree:
	 */
	while (*link) {
		parent = *link;
		entry = rb_entry(parent, struct sched_entity, run_node);
		/*
		 * We dont care about collisions. Nodes with
		 * the same key stay together.
		 */
		if (entity_before(se, entry)) {
			link = &parent->rb_left;
		} else {
			link = &parent->rb_right;
			leftmost = 0;
		}
	}

	/*
	 * Maintain a cache of leftmost tree entries (it is frequently
	 * used):
	 */
	if (leftmost)
		cfs_rq->rb_leftmost = &se->run_node;

	rb_link_node(&se->run_node, parent, link);
	rb_insert_color(&se->run_node, &cfs_rq->tasks_timeline);
}

static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
	if (cfs_rq->rb_leftmost == &se->run_node) {
		struct rb_node *next_node;

		next_node = rb_next(&se->run_node);
		cfs_rq->rb_leftmost = next_node;
	}

	rb_erase(&se->run_node, &cfs_rq->tasks_timeline);
}

struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq)
{
	struct rb_node *left = cfs_rq->rb_leftmost;

	if (!left)
		return NULL;

	return rb_entry(left, struct sched_entity, run_node);
}

static struct sched_entity *__pick_next_entity(struct sched_entity *se)
{
	struct rb_node *next = rb_next(&se->run_node);

	if (!next)
		return NULL;

	return rb_entry(next, struct sched_entity, run_node);
}

#ifdef CONFIG_SCHED_DEBUG
struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
{
	struct rb_node *last = rb_last(&cfs_rq->tasks_timeline);

	if (!last)
		return NULL;

	return rb_entry(last, struct sched_entity, run_node);
}

/**************************************************************
 * Scheduling class statistics methods:
 */

int sched_proc_update_handler(struct ctl_table *table, int write,
		void __user *buffer, size_t *lenp,
		loff_t *ppos)
{
	int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
	int factor = get_update_sysctl_factor();

	if (ret || !write)
		return ret;

	sched_nr_latency = DIV_ROUND_UP(sysctl_sched_latency,
					sysctl_sched_min_granularity);

#define WRT_SYSCTL(name) \
	(normalized_sysctl_##name = sysctl_##name / (factor))
	WRT_SYSCTL(sched_min_granularity);
	WRT_SYSCTL(sched_latency);
	WRT_SYSCTL(sched_wakeup_granularity);
#undef WRT_SYSCTL

	return 0;
}
#endif

/*
 * delta /= w
 */
static inline unsigned long
calc_delta_fair(unsigned long delta, struct sched_entity *se)
{
	if (unlikely(se->load.weight != NICE_0_LOAD))
		delta = calc_delta_mine(delta, NICE_0_LOAD, &se->load);

	return delta;
}

/*
 * The idea is to set a period in which each task runs once.
 *
 * When there are too many tasks (sysctl_sched_nr_latency) we have to stretch
 * this period because otherwise the slices get too small.
 *
 * p = (nr <= nl) ? l : l*nr/nl
 */
static u64 __sched_period(unsigned long nr_running)
{
	u64 period = sysctl_sched_latency;
	unsigned long nr_latency = sched_nr_latency;

	if (unlikely(nr_running > nr_latency)) {
		period = sysctl_sched_min_granularity;
		period *= nr_running;
	}

	return period;
}

/*
 * We calculate the wall-time slice from the period by taking a part
 * proportional to the weight.
 *
 * s = p*P[w/rw]
 */
static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
	u64 slice = __sched_period(cfs_rq->nr_running + !se->on_rq);

	for_each_sched_entity(se) {
		struct load_weight *load;
		struct load_weight lw;

		cfs_rq = cfs_rq_of(se);
		load = &cfs_rq->load;

		if (unlikely(!se->on_rq)) {
			lw = cfs_rq->load;

			update_load_add(&lw, se->load.weight);
			load = &lw;
		}
		slice = calc_delta_mine(slice, se->load.weight, load);
	}
	return slice;
}

/*
 * We calculate the vruntime slice of a to be inserted task
 *
 * vs = s/w
 */
static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
	return calc_delta_fair(sched_slice(cfs_rq, se), se);
}

static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update);
static void update_cfs_shares(struct cfs_rq *cfs_rq);

/*
 * Update the current task's runtime statistics. Skip current tasks that
 * are not in our scheduling class.
 */
static inline void
__update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
	      unsigned long delta_exec)
{
	unsigned long delta_exec_weighted;

	schedstat_set(curr->statistics.exec_max,
		      max((u64)delta_exec, curr->statistics.exec_max));

	curr->sum_exec_runtime += delta_exec;
	schedstat_add(cfs_rq, exec_clock, delta_exec);
	delta_exec_weighted = calc_delta_fair(delta_exec, curr);

	curr->vruntime += delta_exec_weighted;
	update_min_vruntime(cfs_rq);

#if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED
	cfs_rq->load_unacc_exec_time += delta_exec;
#endif
}

static void update_curr(struct cfs_rq *cfs_rq)
{
	struct sched_entity *curr = cfs_rq->curr;
	u64 now = rq_of(cfs_rq)->clock_task;
	unsigned long delta_exec;

	if (unlikely(!curr))
		return;

	/*
	 * Get the amount of time the current task was running
	 * since the last time we changed load (this cannot
	 * overflow on 32 bits):
	 */
	delta_exec = (unsigned long)(now - curr->exec_start);
	if (!delta_exec)
		return;

	__update_curr(cfs_rq, curr, delta_exec);
	curr->exec_start = now;

	if (entity_is_task(curr)) {
		struct task_struct *curtask = task_of(curr);

		trace_sched_stat_runtime(curtask, delta_exec, curr->vruntime);
		cpuacct_charge(curtask, delta_exec);
		account_group_exec_runtime(curtask, delta_exec);
	}

	account_cfs_rq_runtime(cfs_rq, delta_exec);
}

static inline void
update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
	schedstat_set(se->statistics.wait_start, rq_of(cfs_rq)->clock);
}

/*
 * Task is being enqueued - update stats:
 */
static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
	/*
	 * Are we enqueueing a waiting task? (for current tasks
	 * a dequeue/enqueue event is a NOP)
	 */
	if (se != cfs_rq->curr)
		update_stats_wait_start(cfs_rq, se);
}

static void
update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
	schedstat_set(se->statistics.wait_max, max(se->statistics.wait_max,
			rq_of(cfs_rq)->clock - se->statistics.wait_start));
	schedstat_set(se->statistics.wait_count, se->statistics.wait_count + 1);
	schedstat_set(se->statistics.wait_sum, se->statistics.wait_sum +
			rq_of(cfs_rq)->clock - se->statistics.wait_start);
#ifdef CONFIG_SCHEDSTATS
	if (entity_is_task(se)) {
		trace_sched_stat_wait(task_of(se),
			rq_of(cfs_rq)->clock - se->statistics.wait_start);
	}
#endif
	schedstat_set(se->statistics.wait_start, 0);
}

static inline void
update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
	/*
	 * Mark the end of the wait period if dequeueing a
	 * waiting task:
	 */
	if (se != cfs_rq->curr)
		update_stats_wait_end(cfs_rq, se);
}

/*
 * We are picking a new current task - update its stats:
 */
static inline void
update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
	/*
	 * We are starting a new run period:
	 */
	se->exec_start = rq_of(cfs_rq)->clock_task;
}

/**************************************************
 * Scheduling class queueing methods:
 */

static void
account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
	update_load_add(&cfs_rq->load, se->load.weight);
	if (!parent_entity(se))
		update_load_add(&rq_of(cfs_rq)->load, se->load.weight);
#ifdef CONFIG_SMP
	if (entity_is_task(se))
		list_add(&se->group_node, &rq_of(cfs_rq)->cfs_tasks);
#endif
	cfs_rq->nr_running++;
}

static void
account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
	update_load_sub(&cfs_rq->load, se->load.weight);
	if (!parent_entity(se))
		update_load_sub(&rq_of(cfs_rq)->load, se->load.weight);
	if (entity_is_task(se))
		list_del_init(&se->group_node);
	cfs_rq->nr_running--;
}

#ifdef CONFIG_FAIR_GROUP_SCHED
/* we need this in update_cfs_load and load-balance functions below */
static inline int throttled_hierarchy(struct cfs_rq *cfs_rq);
# ifdef CONFIG_SMP
static void update_cfs_rq_load_contribution(struct cfs_rq *cfs_rq,
					    int global_update)
{
	struct task_group *tg = cfs_rq->tg;
	long load_avg;

	load_avg = div64_u64(cfs_rq->load_avg, cfs_rq->load_period+1);
	load_avg -= cfs_rq->load_contribution;

	if (global_update || abs(load_avg) > cfs_rq->load_contribution / 8) {
		atomic_add(load_avg, &tg->load_weight);
		cfs_rq->load_contribution += load_avg;
	}
}

static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
{
	u64 period = sysctl_sched_shares_window;
	u64 now, delta;
	unsigned long load = cfs_rq->load.weight;

	if (cfs_rq->tg == &root_task_group || throttled_hierarchy(cfs_rq))
		return;

	now = rq_of(cfs_rq)->clock_task;
	delta = now - cfs_rq->load_stamp;

	/* truncate load history at 4 idle periods */
	if (cfs_rq->load_stamp > cfs_rq->load_last &&
	    now - cfs_rq->load_last > 4 * period) {
		cfs_rq->load_period = 0;
		cfs_rq->load_avg = 0;
		delta = period - 1;
	}

	cfs_rq->load_stamp = now;
	cfs_rq->load_unacc_exec_time = 0;
	cfs_rq->load_period += delta;
	if (load) {
		cfs_rq->load_last = now;
		cfs_rq->load_avg += delta * load;
	}

	/* consider updating load contribution on each fold or truncate */
	if (global_update || cfs_rq->load_period > period
	    || !cfs_rq->load_period)
		update_cfs_rq_load_contribution(cfs_rq, global_update);

	while (cfs_rq->load_period > period) {
		/*
		 * Inline assembly required to prevent the compiler
		 * optimising this loop into a divmod call.
		 * See __iter_div_u64_rem() for another example of this.
		 */
		asm("" : "+rm" (cfs_rq->load_period));
		cfs_rq->load_period /= 2;
		cfs_rq->load_avg /= 2;
	}

	if (!cfs_rq->curr && !cfs_rq->nr_running && !cfs_rq->load_avg)
		list_del_leaf_cfs_rq(cfs_rq);
}

static inline long calc_tg_weight(struct task_group *tg, struct cfs_rq *cfs_rq)
{
	long tg_weight;

	/*
	 * Use this CPU's actual weight instead of the last load_contribution
	 * to gain a more accurate current total weight. See
	 * update_cfs_rq_load_contribution().
	 */
	tg_weight = atomic_read(&tg->load_weight);
	tg_weight -= cfs_rq->load_contribution;
	tg_weight += cfs_rq->load.weight;

	return tg_weight;
}

static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg)
{
	long tg_weight, load, shares;

	tg_weight = calc_tg_weight(tg, cfs_rq);
	load = cfs_rq->load.weight;

	shares = (tg->shares * load);
	if (tg_weight)
		shares /= tg_weight;

	if (shares < MIN_SHARES)
		shares = MIN_SHARES;
	if (shares > tg->shares)
		shares = tg->shares;

	return shares;
}

static void update_entity_shares_tick(struct cfs_rq *cfs_rq)
{
	if (cfs_rq->load_unacc_exec_time > sysctl_sched_shares_window) {
		update_cfs_load(cfs_rq, 0);
		update_cfs_shares(cfs_rq);
	}
}
# else /* CONFIG_SMP */
static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
{
}

static inline long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg)
{
	return tg->shares;
}

static inline void update_entity_shares_tick(struct cfs_rq *cfs_rq)
{
}
# endif /* CONFIG_SMP */
static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
			    unsigned long weight)
{
	if (se->on_rq) {
		/* commit outstanding execution time */
		if (cfs_rq->curr == se)
			update_curr(cfs_rq);
		account_entity_dequeue(cfs_rq, se);
	}

	update_load_set(&se->load, weight);

	if (se->on_rq)
		account_entity_enqueue(cfs_rq, se);
}

static void update_cfs_shares(struct cfs_rq *cfs_rq)
{
	struct task_group *tg;
	struct sched_entity *se;
	long shares;

	tg = cfs_rq->tg;
	se = tg->se[cpu_of(rq_of(cfs_rq))];
	if (!se || throttled_hierarchy(cfs_rq))
		return;
#ifndef CONFIG_SMP
	if (likely(se->load.weight == tg->shares))
		return;
#endif
	shares = calc_cfs_shares(cfs_rq, tg);

	reweight_entity(cfs_rq_of(se), se, shares);
}
#else /* CONFIG_FAIR_GROUP_SCHED */
static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
{
}

static inline void update_cfs_shares(struct cfs_rq *cfs_rq)
{
}

static inline void update_entity_shares_tick(struct cfs_rq *cfs_rq)
{
}
#endif /* CONFIG_FAIR_GROUP_SCHED */

static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
#ifdef CONFIG_SCHEDSTATS
	struct task_struct *tsk = NULL;

	if (entity_is_task(se))
		tsk = task_of(se);

	if (se->statistics.sleep_start) {
		u64 delta = rq_of(cfs_rq)->clock - se->statistics.sleep_start;

		if ((s64)delta < 0)
			delta = 0;

		if (unlikely(delta > se->statistics.sleep_max))
			se->statistics.sleep_max = delta;

		se->statistics.sleep_start = 0;
		se->statistics.sum_sleep_runtime += delta;

		if (tsk) {
			account_scheduler_latency(tsk, delta >> 10, 1);
			trace_sched_stat_sleep(tsk, delta);
		}
	}
	if (se->statistics.block_start) {
		u64 delta = rq_of(cfs_rq)->clock - se->statistics.block_start;

		if ((s64)delta < 0)
			delta = 0;

		if (unlikely(delta > se->statistics.block_max))
			se->statistics.block_max = delta;

		se->statistics.block_start = 0;
		se->statistics.sum_sleep_runtime += delta;

		if (tsk) {
			if (tsk->in_iowait) {
				se->statistics.iowait_sum += delta;
				se->statistics.iowait_count++;
				trace_sched_stat_iowait(tsk, delta);
			}

			trace_sched_stat_blocked(tsk, delta);

			/*
			 * Blocking time is in units of nanosecs, so shift by
			 * 20 to get a milliseconds-range estimation of the
			 * amount of time that the task spent sleeping:
			 */
			if (unlikely(prof_on == SLEEP_PROFILING)) {
				profile_hits(SLEEP_PROFILING,
						(void *)get_wchan(tsk),
						delta >> 20);
			}
			account_scheduler_latency(tsk, delta >> 10, 0);
		}
	}
#endif
}

static void check_spread(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
#ifdef CONFIG_SCHED_DEBUG
	s64 d = se->vruntime - cfs_rq->min_vruntime;

	if (d < 0)
		d = -d;

	if (d > 3*sysctl_sched_latency)
		schedstat_inc(cfs_rq, nr_spread_over);
#endif
}

static void
place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
{
	u64 vruntime = cfs_rq->min_vruntime;

	/*
	 * The 'current' period is already promised to the current tasks,
	 * however the extra weight of the new task will slow them down a
	 * little, place the new task so that it fits in the slot that
	 * stays open at the end.
	 */
	if (initial && sched_feat(START_DEBIT))
		vruntime += sched_vslice(cfs_rq, se);

	/* sleeps up to a single latency don't count. */
	if (!initial) {
		unsigned long thresh = sysctl_sched_latency;

		/*
		 * Halve their sleep time's effect, to allow
		 * for a gentler effect of sleepers:
		 */
		if (sched_feat(GENTLE_FAIR_SLEEPERS))
			thresh >>= 1;

		vruntime -= thresh;
	}

	/* ensure we never gain time by being placed backwards. */
	vruntime = max_vruntime(se->vruntime, vruntime);

	se->vruntime = vruntime;
}

static void check_enqueue_throttle(struct cfs_rq *cfs_rq);

static void
enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
{
	/*
	 * Update the normalized vruntime before updating min_vruntime
	 * through callig update_curr().
	 */
	if (!(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_WAKING))
		se->vruntime += cfs_rq->min_vruntime;

	/*
	 * Update run-time statistics of the 'current'.
	 */
	update_curr(cfs_rq);
	update_cfs_load(cfs_rq, 0);
	account_entity_enqueue(cfs_rq, se);
	update_cfs_shares(cfs_rq);

	if (flags & ENQUEUE_WAKEUP) {
		place_entity(cfs_rq, se, 0);
		enqueue_sleeper(cfs_rq, se);
	}

	update_stats_enqueue(cfs_rq, se);
	check_spread(cfs_rq, se);
	if (se != cfs_rq->curr)
		__enqueue_entity(cfs_rq, se);
	se->on_rq = 1;

	if (cfs_rq->nr_running == 1) {
		list_add_leaf_cfs_rq(cfs_rq);
		check_enqueue_throttle(cfs_rq);
	}
}

static void __clear_buddies_last(struct sched_entity *se)
{
	for_each_sched_entity(se) {
		struct cfs_rq *cfs_rq = cfs_rq_of(se);
		if (cfs_rq->last == se)
			cfs_rq->last = NULL;
		else
			break;
	}
}

static void __clear_buddies_next(struct sched_entity *se)
{
	for_each_sched_entity(se) {
		struct cfs_rq *cfs_rq = cfs_rq_of(se);
		if (cfs_rq->next == se)
			cfs_rq->next = NULL;
		else
			break;
	}
}

static void __clear_buddies_skip(struct sched_entity *se)
{
	for_each_sched_entity(se) {
		struct cfs_rq *cfs_rq = cfs_rq_of(se);
		if (cfs_rq->skip == se)
			cfs_rq->skip = NULL;
		else
			break;
	}
}

static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
	if (cfs_rq->last == se)
		__clear_buddies_last(se);

	if (cfs_rq->next == se)
		__clear_buddies_next(se);

	if (cfs_rq->skip == se)
		__clear_buddies_skip(se);
}

static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq);

static void
dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
{
	/*
	 * Update run-time statistics of the 'current'.
	 */
	update_curr(cfs_rq);

	update_stats_dequeue(cfs_rq, se);
	if (flags & DEQUEUE_SLEEP) {
#ifdef CONFIG_SCHEDSTATS
		if (entity_is_task(se)) {
			struct task_struct *tsk = task_of(se);

			if (tsk->state & TASK_INTERRUPTIBLE)
				se->statistics.sleep_start = rq_of(cfs_rq)->clock;
			if (tsk->state & TASK_UNINTERRUPTIBLE)
				se->statistics.block_start = rq_of(cfs_rq)->clock;
		}
#endif
	}

	clear_buddies(cfs_rq, se);

	if (se != cfs_rq->curr)
		__dequeue_entity(cfs_rq, se);
	se->on_rq = 0;
	update_cfs_load(cfs_rq, 0);
	account_entity_dequeue(cfs_rq, se);

	/*
	 * Normalize the entity after updating the min_vruntime because the
	 * update can refer to the ->curr item and we need to reflect this
	 * movement in our normalized position.
	 */
	if (!(flags & DEQUEUE_SLEEP))
		se->vruntime -= cfs_rq->min_vruntime;

	/* return excess runtime on last dequeue */
	return_cfs_rq_runtime(cfs_rq);

	update_min_vruntime(cfs_rq);
	update_cfs_shares(cfs_rq);
}

/*
 * Preempt the current task with a newly woken task if needed:
 */
static void
check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
{
	unsigned long ideal_runtime, delta_exec;
	struct sched_entity *se;
	s64 delta;

	ideal_runtime = sched_slice(cfs_rq, curr);
	delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
	if (delta_exec > ideal_runtime) {
		resched_task(rq_of(cfs_rq)->curr);
		/*
		 * The current task ran long enough, ensure it doesn't get
		 * re-elected due to buddy favours.
		 */
		clear_buddies(cfs_rq, curr);
		return;
	}

	/*
	 * Ensure that a task that missed wakeup preemption by a
	 * narrow margin doesn't have to wait for a full slice.
	 * This also mitigates buddy induced latencies under load.
	 */
	if (delta_exec < sysctl_sched_min_granularity)
		return;

	se = __pick_first_entity(cfs_rq);
	delta = curr->vruntime - se->vruntime;

	if (delta < 0)
		return;

	if (delta > ideal_runtime)
		resched_task(rq_of(cfs_rq)->curr);
}

static void
set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
	/* 'current' is not kept within the tree. */
	if (se->on_rq) {
		/*
		 * Any task has to be enqueued before it get to execute on
		 * a CPU. So account for the time it spent waiting on the
		 * runqueue.
		 */
		update_stats_wait_end(cfs_rq, se);
		__dequeue_entity(cfs_rq, se);
	}

	update_stats_curr_start(cfs_rq, se);
	cfs_rq->curr = se;
#ifdef CONFIG_SCHEDSTATS
	/*
	 * Track our maximum slice length, if the CPU's load is at
	 * least twice that of our own weight (i.e. dont track it
	 * when there are only lesser-weight tasks around):
	 */
	if (rq_of(cfs_rq)->load.weight >= 2*se->load.weight) {
		se->statistics.slice_max = max(se->statistics.slice_max,
			se->sum_exec_runtime - se->prev_sum_exec_runtime);
	}
#endif
	se->prev_sum_exec_runtime = se->sum_exec_runtime;
}

static int
wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se);

/*
 * Pick the next process, keeping these things in mind, in this order:
 * 1) keep things fair between processes/task groups
 * 2) pick the "next" process, since someone really wants that to run
 * 3) pick the "last" process, for cache locality
 * 4) do not run the "skip" process, if something else is available
 */
static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
{
	struct sched_entity *se = __pick_first_entity(cfs_rq);
	struct sched_entity *left = se;

	/*
	 * Avoid running the skip buddy, if running something else can
	 * be done without getting too unfair.
	 */
	if (cfs_rq->skip == se) {
		struct sched_entity *second = __pick_next_entity(se);
		if (second && wakeup_preempt_entity(second, left) < 1)
			se = second;
	}

	/*
	 * Prefer last buddy, try to return the CPU to a preempted task.
	 */
	if (cfs_rq->last && wakeup_preempt_entity(cfs_rq->last, left) < 1)
		se = cfs_rq->last;

	/*
	 * Someone really wants this to run. If it's not unfair, run it.
	 */
	if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, left) < 1)
		se = cfs_rq->next;

	clear_buddies(cfs_rq, se);

	return se;
}

static void check_cfs_rq_runtime(struct cfs_rq *cfs_rq);

static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev)
{
	/*
	 * If still on the runqueue then deactivate_task()
	 * was not called and update_curr() has to be done:
	 */
	if (prev->on_rq)
		update_curr(cfs_rq);

	/* throttle cfs_rqs exceeding runtime */
	check_cfs_rq_runtime(cfs_rq);

	check_spread(cfs_rq, prev);
	if (prev->on_rq) {
		update_stats_wait_start(cfs_rq, prev);
		/* Put 'current' back into the tree. */
		__enqueue_entity(cfs_rq, prev);
	}
	cfs_rq->curr = NULL;
}

static void
entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
{
	/*
	 * Update run-time statistics of the 'current'.
	 */
	update_curr(cfs_rq);

	/*
	 * Update share accounting for long-running entities.
	 */
	update_entity_shares_tick(cfs_rq);

#ifdef CONFIG_SCHED_HRTICK
	/*
	 * queued ticks are scheduled to match the slice, so don't bother
	 * validating it and just reschedule.
	 */
	if (queued) {
		resched_task(rq_of(cfs_rq)->curr);
		return;
	}
	/*
	 * don't let the period tick interfere with the hrtick preemption
	 */
	if (!sched_feat(DOUBLE_TICK) &&
			hrtimer_active(&rq_of(cfs_rq)->hrtick_timer))
		return;
#endif

	if (cfs_rq->nr_running > 1)
		check_preempt_tick(cfs_rq, curr);
}


/**************************************************
 * CFS bandwidth control machinery
 */

#ifdef CONFIG_CFS_BANDWIDTH

#ifdef HAVE_JUMP_LABEL
static struct static_key __cfs_bandwidth_used;

static inline bool cfs_bandwidth_used(void)
{
	return static_key_false(&__cfs_bandwidth_used);
}

void account_cfs_bandwidth_used(int enabled, int was_enabled)
{
	/* only need to count groups transitioning between enabled/!enabled */
	if (enabled && !was_enabled)
		static_key_slow_inc(&__cfs_bandwidth_used);
	else if (!enabled && was_enabled)
		static_key_slow_dec(&__cfs_bandwidth_used);
}
#else /* HAVE_JUMP_LABEL */
static bool cfs_bandwidth_used(void)
{
	return true;
}

void account_cfs_bandwidth_used(int enabled, int was_enabled) {}
#endif /* HAVE_JUMP_LABEL */

/*
 * default period for cfs group bandwidth.
 * default: 0.1s, units: nanoseconds
 */
static inline u64 default_cfs_period(void)
{
	return 100000000ULL;
}

static inline u64 sched_cfs_bandwidth_slice(void)
{
	return (u64)sysctl_sched_cfs_bandwidth_slice * NSEC_PER_USEC;
}

/*
 * Replenish runtime according to assigned quota and update expiration time.
 * We use sched_clock_cpu directly instead of rq->clock to avoid adding
 * additional synchronization around rq->lock.
 *
 * requires cfs_b->lock
 */
void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b)
{
	u64 now;

	if (cfs_b->quota == RUNTIME_INF)
		return;

	now = sched_clock_cpu(smp_processor_id());
	cfs_b->runtime = cfs_b->quota;
	cfs_b->runtime_expires = now + ktime_to_ns(cfs_b->period);
}

static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
{
	return &tg->cfs_bandwidth;
}

/* returns 0 on failure to allocate runtime */
static int assign_cfs_rq_runtime(struct cfs_rq *cfs_rq)
{
	struct task_group *tg = cfs_rq->tg;
	struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg);
	u64 amount = 0, min_amount, expires;

	/* note: this is a positive sum as runtime_remaining <= 0 */
	min_amount = sched_cfs_bandwidth_slice() - cfs_rq->runtime_remaining;

	raw_spin_lock(&cfs_b->lock);
	if (cfs_b->quota == RUNTIME_INF)
		amount = min_amount;
	else {
		/*
		 * If the bandwidth pool has become inactive, then at least one
		 * period must have elapsed since the last consumption.
		 * Refresh the global state and ensure bandwidth timer becomes
		 * active.
		 */
		if (!cfs_b->timer_active) {
			__refill_cfs_bandwidth_runtime(cfs_b);
			__start_cfs_bandwidth(cfs_b);
		}

		if (cfs_b->runtime > 0) {
			amount = min(cfs_b->runtime, min_amount);
			cfs_b->runtime -= amount;
			cfs_b->idle = 0;
		}
	}
	expires = cfs_b->runtime_expires;
	raw_spin_unlock(&cfs_b->lock);

	cfs_rq->runtime_remaining += amount;
	/*
	 * we may have advanced our local expiration to account for allowed
	 * spread between our sched_clock and the one on which runtime was
	 * issued.
	 */
	if ((s64)(expires - cfs_rq->runtime_expires) > 0)
		cfs_rq->runtime_expires = expires;

	return cfs_rq->runtime_remaining > 0;
}

/*
 * Note: This depends on the synchronization provided by sched_clock and the
 * fact that rq->clock snapshots this value.
 */
static void expire_cfs_rq_runtime(struct cfs_rq *cfs_rq)
{
	struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
	struct rq *rq = rq_of(cfs_rq);

	/* if the deadline is ahead of our clock, nothing to do */
	if (likely((s64)(rq->clock - cfs_rq->runtime_expires) < 0))
		return;

	if (cfs_rq->runtime_remaining < 0)
		return;

	/*
	 * If the local deadline has passed we have to consider the
	 * possibility that our sched_clock is 'fast' and the global deadline
	 * has not truly expired.
	 *
	 * Fortunately we can check determine whether this the case by checking
	 * whether the global deadline has advanced.
	 */

	if ((s64)(cfs_rq->runtime_expires - cfs_b->runtime_expires) >= 0) {
		/* extend local deadline, drift is bounded above by 2 ticks */
		cfs_rq->runtime_expires += TICK_NSEC;
	} else {
		/* global deadline is ahead, expiration has passed */
		cfs_rq->runtime_remaining = 0;
	}
}

static void __account_cfs_rq_runtime(struct cfs_rq *cfs_rq,
				     unsigned long delta_exec)
{
	/* dock delta_exec before expiring quota (as it could span periods) */
	cfs_rq->runtime_remaining -= delta_exec;
	expire_cfs_rq_runtime(cfs_rq);

	if (likely(cfs_rq->runtime_remaining > 0))
		return;

	/*
	 * if we're unable to extend our runtime we resched so that the active
	 * hierarchy can be throttled
	 */
	if (!assign_cfs_rq_runtime(cfs_rq) && likely(cfs_rq->curr))
		resched_task(rq_of(cfs_rq)->curr);
}

static __always_inline
void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, unsigned long delta_exec)
{
	if (!cfs_bandwidth_used() || !cfs_rq->runtime_enabled)
		return;

	__account_cfs_rq_runtime(cfs_rq, delta_exec);
}

static inline int cfs_rq_throttled(struct cfs_rq *cfs_rq)
{
	return cfs_bandwidth_used() && cfs_rq->throttled;
}

/* check whether cfs_rq, or any parent, is throttled */
static inline int throttled_hierarchy(struct cfs_rq *cfs_rq)
{
	return cfs_bandwidth_used() && cfs_rq->throttle_count;
}

/*
 * Ensure that neither of the group entities corresponding to src_cpu or
 * dest_cpu are members of a throttled hierarchy when performing group
 * load-balance operations.
 */
static inline int throttled_lb_pair(struct task_group *tg,
				    int src_cpu, int dest_cpu)
{
	struct cfs_rq *src_cfs_rq, *dest_cfs_rq;

	src_cfs_rq = tg->cfs_rq[src_cpu];
	dest_cfs_rq = tg->cfs_rq[dest_cpu];

	return throttled_hierarchy(src_cfs_rq) ||
	       throttled_hierarchy(dest_cfs_rq);
}

/* updated child weight may affect parent so we have to do this bottom up */
static int tg_unthrottle_up(struct task_group *tg, void *data)
{
	struct rq *rq = data;
	struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)];

	cfs_rq->throttle_count--;
#ifdef CONFIG_SMP
	if (!cfs_rq->throttle_count) {
		u64 delta = rq->clock_task - cfs_rq->load_stamp;

		/* leaving throttled state, advance shares averaging windows */
		cfs_rq->load_stamp += delta;
		cfs_rq->load_last += delta;

		/* update entity weight now that we are on_rq again */
		update_cfs_shares(cfs_rq);
	}
#endif

	return 0;
}

static int tg_throttle_down(struct task_group *tg, void *data)
{
	struct rq *rq = data;
	struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)];

	/* group is entering throttled state, record last load */
	if (!cfs_rq->throttle_count)
		update_cfs_load(cfs_rq, 0);
	cfs_rq->throttle_count++;

	return 0;
}

static void throttle_cfs_rq(struct cfs_rq *cfs_rq)
{
	struct rq *rq = rq_of(cfs_rq);
	struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
	struct sched_entity *se;
	long task_delta, dequeue = 1;

	se = cfs_rq->tg->se[cpu_of(rq_of(cfs_rq))];

	/* account load preceding throttle */
	rcu_read_lock();
	walk_tg_tree_from(cfs_rq->tg, tg_throttle_down, tg_nop, (void *)rq);
	rcu_read_unlock();

	task_delta = cfs_rq->h_nr_running;
	for_each_sched_entity(se) {
		struct cfs_rq *qcfs_rq = cfs_rq_of(se);
		/* throttled entity or throttle-on-deactivate */
		if (!se->on_rq)
			break;

		if (dequeue)
			dequeue_entity(qcfs_rq, se, DEQUEUE_SLEEP);
		qcfs_rq->h_nr_running -= task_delta;

		if (qcfs_rq->load.weight)
			dequeue = 0;
	}

	if (!se)
		rq->nr_running -= task_delta;

	cfs_rq->throttled = 1;
	cfs_rq->throttled_timestamp = rq->clock;
	raw_spin_lock(&cfs_b->lock);
	list_add_tail_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq);
	raw_spin_unlock(&cfs_b->lock);
}

void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
{
	struct rq *rq = rq_of(cfs_rq);
	struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
	struct sched_entity *se;
	int enqueue = 1;
	long task_delta;

	se = cfs_rq->tg->se[cpu_of(rq_of(cfs_rq))];

	cfs_rq->throttled = 0;
	raw_spin_lock(&cfs_b->lock);
	cfs_b->throttled_time += rq->clock - cfs_rq->throttled_timestamp;
	list_del_rcu(&cfs_rq->throttled_list);
	raw_spin_unlock(&cfs_b->lock);
	cfs_rq->throttled_timestamp = 0;

	update_rq_clock(rq);
	/* update hierarchical throttle state */
	walk_tg_tree_from(cfs_rq->tg, tg_nop, tg_unthrottle_up, (void *)rq);

	if (!cfs_rq->load.weight)
		return;

	task_delta = cfs_rq->h_nr_running;
	for_each_sched_entity(se) {
		if (se->on_rq)
			enqueue = 0;

		cfs_rq = cfs_rq_of(se);
		if (enqueue)
			enqueue_entity(cfs_rq, se, ENQUEUE_WAKEUP);
		cfs_rq->h_nr_running += task_delta;

		if (cfs_rq_throttled(cfs_rq))
			break;
	}

	if (!se)
		rq->nr_running += task_delta;

	/* determine whether we need to wake up potentially idle cpu */
	if (rq->curr == rq->idle && rq->cfs.nr_running)
		resched_task(rq->curr);
}

static u64 distribute_cfs_runtime(struct cfs_bandwidth *cfs_b,
		u64 remaining, u64 expires)
{
	struct cfs_rq *cfs_rq;
	u64 runtime = remaining;

	rcu_read_lock();
	list_for_each_entry_rcu(cfs_rq, &cfs_b->throttled_cfs_rq,
				throttled_list) {
		struct rq *rq = rq_of(cfs_rq);

		raw_spin_lock(&rq->lock);
		if (!cfs_rq_throttled(cfs_rq))
			goto next;

		runtime = -cfs_rq->runtime_remaining + 1;
		if (runtime > remaining)
			runtime = remaining;
		remaining -= runtime;

		cfs_rq->runtime_remaining += runtime;
		cfs_rq->runtime_expires = expires;

		/* we check whether we're throttled above */
		if (cfs_rq->runtime_remaining > 0)
			unthrottle_cfs_rq(cfs_rq);

next:
		raw_spin_unlock(&rq->lock);

		if (!remaining)
			break;
	}
	rcu_read_unlock();

	return remaining;
}

/*
 * Responsible for refilling a task_group's bandwidth and unthrottling its
 * cfs_rqs as appropriate. If there has been no activity within the last
 * period the timer is deactivated until scheduling resumes; cfs_b->idle is
 * used to track this state.
 */
static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
{
	u64 runtime, runtime_expires;
	int idle = 1, throttled;

	raw_spin_lock(&cfs_b->lock);
	/* no need to continue the timer with no bandwidth constraint */
	if (cfs_b->quota == RUNTIME_INF)
		goto out_unlock;

	throttled = !list_empty(&cfs_b->throttled_cfs_rq);
	/* idle depends on !throttled (for the case of a large deficit) */
	idle = cfs_b->idle && !throttled;
	cfs_b->nr_periods += overrun;

	/* if we're going inactive then everything else can be deferred */
	if (idle)
		goto out_unlock;

	__refill_cfs_bandwidth_runtime(cfs_b);

	if (!throttled) {
		/* mark as potentially idle for the upcoming period */
		cfs_b->idle = 1;
		goto out_unlock;
	}

	/* account preceding periods in which throttling occurred */
	cfs_b->nr_throttled += overrun;

	/*
	 * There are throttled entities so we must first use the new bandwidth
	 * to unthrottle them before making it generally available.  This
	 * ensures that all existing debts will be paid before a new cfs_rq is
	 * allowed to run.
	 */
	runtime = cfs_b->runtime;
	runtime_expires = cfs_b->runtime_expires;
	cfs_b->runtime = 0;

	/*
	 * This check is repeated as we are holding onto the new bandwidth
	 * while we unthrottle.  This can potentially race with an unthrottled
	 * group trying to acquire new bandwidth from the global pool.
	 */
	while (throttled && runtime > 0) {
		raw_spin_unlock(&cfs_b->lock);
		/* we can't nest cfs_b->lock while distributing bandwidth */
		runtime = distribute_cfs_runtime(cfs_b, runtime,
						 runtime_expires);
		raw_spin_lock(&cfs_b->lock);

		throttled = !list_empty(&cfs_b->throttled_cfs_rq);
	}

	/* return (any) remaining runtime */
	cfs_b->runtime = runtime;
	/*
	 * While we are ensured activity in the period following an
	 * unthrottle, this also covers the case in which the new bandwidth is
	 * insufficient to cover the existing bandwidth deficit.  (Forcing the
	 * timer to remain active while there are any throttled entities.)
	 */
	cfs_b->idle = 0;
out_unlock:
	if (idle)
		cfs_b->timer_active = 0;
	raw_spin_unlock(&cfs_b->lock);

	return idle;
}

/* a cfs_rq won't donate quota below this amount */
static const u64 min_cfs_rq_runtime = 1 * NSEC_PER_MSEC;
/* minimum remaining period time to redistribute slack quota */
static const u64 min_bandwidth_expiration = 2 * NSEC_PER_MSEC;
/* how long we wait to gather additional slack before distributing */
static const u64 cfs_bandwidth_slack_period = 5 * NSEC_PER_MSEC;

/* are we near the end of the current quota period? */
static int runtime_refresh_within(struct cfs_bandwidth *cfs_b, u64 min_expire)
{
	struct hrtimer *refresh_timer = &cfs_b->period_timer;
	u64 remaining;

	/* if the call-back is running a quota refresh is already occurring */
	if (hrtimer_callback_running(refresh_timer))
		return 1;

	/* is a quota refresh about to occur? */
	remaining = ktime_to_ns(hrtimer_expires_remaining(refresh_timer));
	if (remaining < min_expire)
		return 1;

	return 0;
}

static void start_cfs_slack_bandwidth(struct cfs_bandwidth *cfs_b)
{
	u64 min_left = cfs_bandwidth_slack_period + min_bandwidth_expiration;

	/* if there's a quota refresh soon don't bother with slack */
	if (runtime_refresh_within(cfs_b, min_left))
		return;

	start_bandwidth_timer(&cfs_b->slack_timer,
				ns_to_ktime(cfs_bandwidth_slack_period));
}

/* we know any runtime found here is valid as update_curr() precedes return */
static void __return_cfs_rq_runtime(struct cfs_rq *cfs_rq)
{
	struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
	s64 slack_runtime = cfs_rq->runtime_remaining - min_cfs_rq_runtime;

	if (slack_runtime <= 0)
		return;

	raw_spin_lock(&cfs_b->lock);
	if (cfs_b->quota != RUNTIME_INF &&
	    cfs_rq->runtime_expires == cfs_b->runtime_expires) {
		cfs_b->runtime += slack_runtime;

		/* we are under rq->lock, defer unthrottling using a timer */
		if (cfs_b->runtime > sched_cfs_bandwidth_slice() &&
		    !list_empty(&cfs_b->throttled_cfs_rq))
			start_cfs_slack_bandwidth(cfs_b);
	}
	raw_spin_unlock(&cfs_b->lock);

	/* even if it's not valid for return we don't want to try again */
	cfs_rq->runtime_remaining -= slack_runtime;
}

static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq)
{
	if (!cfs_bandwidth_used())
		return;

	if (!cfs_rq->runtime_enabled || cfs_rq->nr_running)
		return;

	__return_cfs_rq_runtime(cfs_rq);
}

/*
 * This is done with a timer (instead of inline with bandwidth return) since
 * it's necessary to juggle rq->locks to unthrottle their respective cfs_rqs.
 */
static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b)
{
	u64 runtime = 0, slice = sched_cfs_bandwidth_slice();
	u64 expires;

	/* confirm we're still not at a refresh boundary */
	if (runtime_refresh_within(cfs_b, min_bandwidth_expiration))
		return;

	raw_spin_lock(&cfs_b->lock);
	if (cfs_b->quota != RUNTIME_INF && cfs_b->runtime > slice) {
		runtime = cfs_b->runtime;
		cfs_b->runtime = 0;
	}
	expires = cfs_b->runtime_expires;
	raw_spin_unlock(&cfs_b->lock);

	if (!runtime)
		return;

	runtime = distribute_cfs_runtime(cfs_b, runtime, expires);

	raw_spin_lock(&cfs_b->lock);
	if (expires == cfs_b->runtime_expires)
		cfs_b->runtime = runtime;
	raw_spin_unlock(&cfs_b->lock);
}

/*
 * When a group wakes up we want to make sure that its quota is not already
 * expired/exceeded, otherwise it may be allowed to steal additional ticks of
 * runtime as update_curr() throttling can not not trigger until it's on-rq.
 */
static void check_enqueue_throttle(struct cfs_rq *cfs_rq)
{
	if (!cfs_bandwidth_used())
		return;

	/* an active group must be handled by the update_curr()->put() path */
	if (!cfs_rq->runtime_enabled || cfs_rq->curr)
		return;

	/* ensure the group is not already throttled */
	if (cfs_rq_throttled(cfs_rq))
		return;

	/* update runtime allocation */
	account_cfs_rq_runtime(cfs_rq, 0);
	if (cfs_rq->runtime_remaining <= 0)
		throttle_cfs_rq(cfs_rq);
}

/* conditionally throttle active cfs_rq's from put_prev_entity() */
static void check_cfs_rq_runtime(struct cfs_rq *cfs_rq)
{
	if (!cfs_bandwidth_used())
		return;

	if (likely(!cfs_rq->runtime_enabled || cfs_rq->runtime_remaining > 0))
		return;

	/*
	 * it's possible for a throttled entity to be forced into a running
	 * state (e.g. set_curr_task), in this case we're finished.
	 */
	if (cfs_rq_throttled(cfs_rq))
		return;

	throttle_cfs_rq(cfs_rq);
}

static inline u64 default_cfs_period(void);
static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun);
static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b);

static enum hrtimer_restart sched_cfs_slack_timer(struct hrtimer *timer)
{
	struct cfs_bandwidth *cfs_b =
		container_of(timer, struct cfs_bandwidth, slack_timer);
	do_sched_cfs_slack_timer(cfs_b);

	return HRTIMER_NORESTART;
}

static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer)
{
	struct cfs_bandwidth *cfs_b =
		container_of(timer, struct cfs_bandwidth, period_timer);
	ktime_t now;
	int overrun;
	int idle = 0;

	for (;;) {
		now = hrtimer_cb_get_time(timer);
		overrun = hrtimer_forward(timer, now, cfs_b->period);

		if (!overrun)
			break;

		idle = do_sched_cfs_period_timer(cfs_b, overrun);
	}

	return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;
}

void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
{
	raw_spin_lock_init(&cfs_b->lock);
	cfs_b->runtime = 0;
	cfs_b->quota = RUNTIME_INF;
	cfs_b->period = ns_to_ktime(default_cfs_period());

	INIT_LIST_HEAD(&cfs_b->throttled_cfs_rq);
	hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
	cfs_b->period_timer.function = sched_cfs_period_timer;
	hrtimer_init(&cfs_b->slack_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
	cfs_b->slack_timer.function = sched_cfs_slack_timer;
}

static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq)
{
	cfs_rq->runtime_enabled = 0;
	INIT_LIST_HEAD(&cfs_rq->throttled_list);
}

/* requires cfs_b->lock, may release to reprogram timer */
void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
{
	/*
	 * The timer may be active because we're trying to set a new bandwidth
	 * period or because we're racing with the tear-down path
	 * (timer_active==0 becomes visible before the hrtimer call-back
	 * terminates).  In either case we ensure that it's re-programmed
	 */
	while (unlikely(hrtimer_active(&cfs_b->period_timer))) {
		raw_spin_unlock(&cfs_b->lock);
		/* ensure cfs_b->lock is available while we wait */
		hrtimer_cancel(&cfs_b->period_timer);

		raw_spin_lock(&cfs_b->lock);
		/* if someone else restarted the timer then we're done */
		if (cfs_b->timer_active)
			return;
	}

	cfs_b->timer_active = 1;
	start_bandwidth_timer(&cfs_b->period_timer, cfs_b->period);
}

static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
{
	hrtimer_cancel(&cfs_b->period_timer);
	hrtimer_cancel(&cfs_b->slack_timer);
}

void unthrottle_offline_cfs_rqs(struct rq *rq)
{
	struct cfs_rq *cfs_rq;

	for_each_leaf_cfs_rq(rq, cfs_rq) {
		struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);

		if (!cfs_rq->runtime_enabled)
			continue;

		/*
		 * clock_task is not advancing so we just need to make sure
		 * there's some valid quota amount
		 */
		cfs_rq->runtime_remaining = cfs_b->quota;
		if (cfs_rq_throttled(cfs_rq))
			unthrottle_cfs_rq(cfs_rq);
	}
}

#else /* CONFIG_CFS_BANDWIDTH */
static __always_inline
void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, unsigned long delta_exec) {}
static void check_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
static void check_enqueue_throttle(struct cfs_rq *cfs_rq) {}
static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}

static inline int cfs_rq_throttled(struct cfs_rq *cfs_rq)
{
	return 0;
}

static inline int throttled_hierarchy(struct cfs_rq *cfs_rq)
{
	return 0;
}

static inline int throttled_lb_pair(struct task_group *tg,
				    int src_cpu, int dest_cpu)
{
	return 0;
}

void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}

#ifdef CONFIG_FAIR_GROUP_SCHED
static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
#endif

static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
{
	return NULL;
}
static inline void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
void unthrottle_offline_cfs_rqs(struct rq *rq) {}

#endif /* CONFIG_CFS_BANDWIDTH */

/**************************************************
 * CFS operations on tasks:
 */

#ifdef CONFIG_SCHED_HRTICK
static void hrtick_start_fair(struct rq *rq, struct task_struct *p)
{
	struct sched_entity *se = &p->se;
	struct cfs_rq *cfs_rq = cfs_rq_of(se);

	WARN_ON(task_rq(p) != rq);

	if (cfs_rq->nr_running > 1) {
		u64 slice = sched_slice(cfs_rq, se);
		u64 ran = se->sum_exec_runtime - se->prev_sum_exec_runtime;
		s64 delta = slice - ran;

		if (delta < 0) {
			if (rq->curr == p)
				resched_task(p);
			return;
		}

		/*
		 * Don't schedule slices shorter than 10000ns, that just
		 * doesn't make sense. Rely on vruntime for fairness.
		 */
		if (rq->curr != p)
			delta = max_t(s64, 10000LL, delta);

		hrtick_start(rq, delta);
	}
}

/*
 * called from enqueue/dequeue and updates the hrtick when the
 * current task is from our class and nr_running is low enough
 * to matter.
 */
static void hrtick_update(struct rq *rq)
{
	struct task_struct *curr = rq->curr;

	if (!hrtick_enabled(rq) || curr->sched_class != &fair_sched_class)
		return;

	if (cfs_rq_of(&curr->se)->nr_running < sched_nr_latency)
		hrtick_start_fair(rq, curr);
}
#else /* !CONFIG_SCHED_HRTICK */
static inline void
hrtick_start_fair(struct rq *rq, struct task_struct *p)
{
}

static inline void hrtick_update(struct rq *rq)
{
}
#endif

/*
 * The enqueue_task method is called before nr_running is
 * increased. Here we update the fair scheduling stats and
 * then put the task into the rbtree:
 */
static void
enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
{
	struct cfs_rq *cfs_rq;
	struct sched_entity *se = &p->se;

	for_each_sched_entity(se) {
		if (se->on_rq)
			break;
		cfs_rq = cfs_rq_of(se);
		enqueue_entity(cfs_rq, se, flags);

		/*
		 * end evaluation on encountering a throttled cfs_rq
		 *
		 * note: in the case of encountering a throttled cfs_rq we will
		 * post the final h_nr_running increment below.
		*/
		if (cfs_rq_throttled(cfs_rq))
			break;
		cfs_rq->h_nr_running++;

		flags = ENQUEUE_WAKEUP;
	}

	for_each_sched_entity(se) {
		cfs_rq = cfs_rq_of(se);
		cfs_rq->h_nr_running++;

		if (cfs_rq_throttled(cfs_rq))
			break;

		update_cfs_load(cfs_rq, 0);
		update_cfs_shares(cfs_rq);
	}

	if (!se)
		inc_nr_running(rq);
	hrtick_update(rq);
}

static void set_next_buddy(struct sched_entity *se);

/*
 * The dequeue_task method is called before nr_running is
 * decreased. We remove the task from the rbtree and
 * update the fair scheduling stats:
 */
static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
{
	struct cfs_rq *cfs_rq;
	struct sched_entity *se = &p->se;
	int task_sleep = flags & DEQUEUE_SLEEP;

	for_each_sched_entity(se) {
		cfs_rq = cfs_rq_of(se);
		dequeue_entity(cfs_rq, se, flags);

		/*
		 * end evaluation on encountering a throttled cfs_rq
		 *
		 * note: in the case of encountering a throttled cfs_rq we will
		 * post the final h_nr_running decrement below.
		*/
		if (cfs_rq_throttled(cfs_rq))
			break;
		cfs_rq->h_nr_running--;

		/* Don't dequeue parent if it has other entities besides us */
		if (cfs_rq->load.weight) {
			/*
			 * Bias pick_next to pick a task from this cfs_rq, as
			 * p is sleeping when it is within its sched_slice.
			 */
			if (task_sleep && parent_entity(se))
				set_next_buddy(parent_entity(se));

			/* avoid re-evaluating load for this entity */
			se = parent_entity(se);
			break;
		}
		flags |= DEQUEUE_SLEEP;
	}

	for_each_sched_entity(se) {
		cfs_rq = cfs_rq_of(se);
		cfs_rq->h_nr_running--;

		if (cfs_rq_throttled(cfs_rq))
			break;

		update_cfs_load(cfs_rq, 0);
		update_cfs_shares(cfs_rq);
	}

	if (!se)
		dec_nr_running(rq);
	hrtick_update(rq);
}

#ifdef CONFIG_SMP
/* Used instead of source_load when we know the type == 0 */
static unsigned long weighted_cpuload(const int cpu)
{
	return cpu_rq(cpu)->load.weight;
}

/*
 * Return a low guess at the load of a migration-source cpu weighted
 * according to the scheduling class and "nice" value.
 *
 * We want to under-estimate the load of migration sources, to
 * balance conservatively.
 */
static unsigned long source_load(int cpu, int type)
{
	struct rq *rq = cpu_rq(cpu);
	unsigned long total = weighted_cpuload(cpu);

	if (type == 0 || !sched_feat(LB_BIAS))
		return total;

	return min(rq->cpu_load[type-1], total);
}

/*
 * Return a high guess at the load of a migration-target cpu weighted
 * according to the scheduling class and "nice" value.
 */
static unsigned long target_load(int cpu, int type)
{
	struct rq *rq = cpu_rq(cpu);
	unsigned long total = weighted_cpuload(cpu);

	if (type == 0 || !sched_feat(LB_BIAS))
		return total;

	return max(rq->cpu_load[type-1], total);
}

static unsigned long power_of(int cpu)
{
	return cpu_rq(cpu)->cpu_power;
}

static unsigned long cpu_avg_load_per_task(int cpu)
{
	struct rq *rq = cpu_rq(cpu);
	unsigned long nr_running = ACCESS_ONCE(rq->nr_running);

	if (nr_running)
		return rq->load.weight / nr_running;

	return 0;
}


static void task_waking_fair(struct task_struct *p)
{
	struct sched_entity *se = &p->se;
	struct cfs_rq *cfs_rq = cfs_rq_of(se);
	u64 min_vruntime;

#ifndef CONFIG_64BIT
	u64 min_vruntime_copy;

	do {
		min_vruntime_copy = cfs_rq->min_vruntime_copy;
		smp_rmb();
		min_vruntime = cfs_rq->min_vruntime;
	} while (min_vruntime != min_vruntime_copy);
#else
	min_vruntime = cfs_rq->min_vruntime;
#endif

	se->vruntime -= min_vruntime;
}

#ifdef CONFIG_FAIR_GROUP_SCHED
/*
 * effective_load() calculates the load change as seen from the root_task_group
 *
 * Adding load to a group doesn't make a group heavier, but can cause movement
 * of group shares between cpus. Assuming the shares were perfectly aligned one
 * can calculate the shift in shares.
 *
 * Calculate the effective load difference if @wl is added (subtracted) to @tg
 * on this @cpu and results in a total addition (subtraction) of @wg to the
 * total group weight.
 *
 * Given a runqueue weight distribution (rw_i) we can compute a shares
 * distribution (s_i) using:
 *
 *   s_i = rw_i / \Sum rw_j						(1)
 *
 * Suppose we have 4 CPUs and our @tg is a direct child of the root group and
 * has 7 equal weight tasks, distributed as below (rw_i), with the resulting
 * shares distribution (s_i):
 *
 *   rw_i = {   2,   4,   1,   0 }
 *   s_i  = { 2/7, 4/7, 1/7,   0 }
 *
 * As per wake_affine() we're interested in the load of two CPUs (the CPU the
 * task used to run on and the CPU the waker is running on), we need to
 * compute the effect of waking a task on either CPU and, in case of a sync
 * wakeup, compute the effect of the current task going to sleep.
 *
 * So for a change of @wl to the local @cpu with an overall group weight change
 * of @wl we can compute the new shares distribution (s'_i) using:
 *
 *   s'_i = (rw_i + @wl) / (@wg + \Sum rw_j)				(2)
 *
 * Suppose we're interested in CPUs 0 and 1, and want to compute the load
 * differences in waking a task to CPU 0. The additional task changes the
 * weight and shares distributions like:
 *
 *   rw'_i = {   3,   4,   1,   0 }
 *   s'_i  = { 3/8, 4/8, 1/8,   0 }
 *
 * We can then compute the difference in effective weight by using:
 *
 *   dw_i = S * (s'_i - s_i)						(3)
 *
 * Where 'S' is the group weight as seen by its parent.
 *
 * Therefore the effective change in loads on CPU 0 would be 5/56 (3/8 - 2/7)
 * times the weight of the group. The effect on CPU 1 would be -4/56 (4/8 -
 * 4/7) times the weight of the group.
 */
static long effective_load(struct task_group *tg, int cpu, long wl, long wg)
{
	struct sched_entity *se = tg->se[cpu];

	if (!tg->parent)	/* the trivial, non-cgroup case */
		return wl;

	for_each_sched_entity(se) {
		long w, W;

		tg = se->my_q->tg;

		/*
		 * W = @wg + \Sum rw_j
		 */
		W = wg + calc_tg_weight(tg, se->my_q);

		/*
		 * w = rw_i + @wl
		 */
		w = se->my_q->load.weight + wl;

		/*
		 * wl = S * s'_i; see (2)
		 */
		if (W > 0 && w < W)
			wl = (w * tg->shares) / W;
		else
			wl = tg->shares;

		/*
		 * Per the above, wl is the new se->load.weight value; since
		 * those are clipped to [MIN_SHARES, ...) do so now. See
		 * calc_cfs_shares().
		 */
		if (wl < MIN_SHARES)
			wl = MIN_SHARES;

		/*
		 * wl = dw_i = S * (s'_i - s_i); see (3)
		 */
		wl -= se->load.weight;

		/*
		 * Recursively apply this logic to all parent groups to compute
		 * the final effective load change on the root group. Since
		 * only the @tg group gets extra weight, all parent groups can
		 * only redistribute existing shares. @wl is the shift in shares
		 * resulting from this level per the above.
		 */
		wg = 0;
	}

	return wl;
}
#else

static inline unsigned long effective_load(struct task_group *tg, int cpu,
		unsigned long wl, unsigned long wg)
{
	return wl;
}

#endif

static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
{
	s64 this_load, load;
	int idx, this_cpu, prev_cpu;
	unsigned long tl_per_task;
	struct task_group *tg;
	unsigned long weight;
	int balanced;

	idx	  = sd->wake_idx;
	this_cpu  = smp_processor_id();
	prev_cpu  = task_cpu(p);
	load	  = source_load(prev_cpu, idx);
	this_load = target_load(this_cpu, idx);

	/*
	 * If sync wakeup then subtract the (maximum possible)
	 * effect of the currently running task from the load
	 * of the current CPU:
	 */
	if (sync) {
		tg = task_group(current);
		weight = current->se.load.weight;

		this_load += effective_load(tg, this_cpu, -weight, -weight);
		load += effective_load(tg, prev_cpu, 0, -weight);
	}

	tg = task_group(p);
	weight = p->se.load.weight;

	/*
	 * In low-load situations, where prev_cpu is idle and this_cpu is idle
	 * due to the sync cause above having dropped this_load to 0, we'll
	 * always have an imbalance, but there's really nothing you can do
	 * about that, so that's good too.
	 *
	 * Otherwise check if either cpus are near enough in load to allow this
	 * task to be woken on this_cpu.
	 */
	if (this_load > 0) {
		s64 this_eff_load, prev_eff_load;

		this_eff_load = 100;
		this_eff_load *= power_of(prev_cpu);
		this_eff_load *= this_load +
			effective_load(tg, this_cpu, weight, weight);

		prev_eff_load = 100 + (sd->imbalance_pct - 100) / 2;
		prev_eff_load *= power_of(this_cpu);
		prev_eff_load *= load + effective_load(tg, prev_cpu, 0, weight);

		balanced = this_eff_load <= prev_eff_load;
	} else
		balanced = true;

	/*
	 * If the currently running task will sleep within
	 * a reasonable amount of time then attract this newly
	 * woken task:
	 */
	if (sync && balanced)
		return 1;

	schedstat_inc(p, se.statistics.nr_wakeups_affine_attempts);
	tl_per_task = cpu_avg_load_per_task(this_cpu);

	if (balanced ||
	    (this_load <= load &&
	     this_load + target_load(prev_cpu, idx) <= tl_per_task)) {
		/*
		 * This domain has SD_WAKE_AFFINE and
		 * p is cache cold in this domain, and
		 * there is no bad imbalance.
		 */
		schedstat_inc(sd, ttwu_move_affine);
		schedstat_inc(p, se.statistics.nr_wakeups_affine);

		return 1;
	}
	return 0;
}

/*
 * find_idlest_group finds and returns the least busy CPU group within the
 * domain.
 */
static struct sched_group *
find_idlest_group(struct sched_domain *sd, struct task_struct *p,
		  int this_cpu, int load_idx)
{
	struct sched_group *idlest = NULL, *group = sd->groups;
	unsigned long min_load = ULONG_MAX, this_load = 0;
	int imbalance = 100 + (sd->imbalance_pct-100)/2;

	do {
		unsigned long load, avg_load;
		int local_group;
		int i;

		/* Skip over this group if it has no CPUs allowed */
		if (!cpumask_intersects(sched_group_cpus(group),
					tsk_cpus_allowed(p)))
			continue;

		local_group = cpumask_test_cpu(this_cpu,
					       sched_group_cpus(group));

		/* Tally up the load of all CPUs in the group */
		avg_load = 0;

		for_each_cpu(i, sched_group_cpus(group)) {
			/* Bias balancing toward cpus of our domain */
			if (local_group)
				load = source_load(i, load_idx);
			else
				load = target_load(i, load_idx);

			avg_load += load;
		}

		/* Adjust by relative CPU power of the group */
		avg_load = (avg_load * SCHED_POWER_SCALE) / group->sgp->power;

		if (local_group) {
			this_load = avg_load;
		} else if (avg_load < min_load) {
			min_load = avg_load;
			idlest = group;
		}
	} while (group = group->next, group != sd->groups);

	if (!idlest || 100*this_load < imbalance*min_load)
		return NULL;
	return idlest;
}

/*
 * find_idlest_cpu - find the idlest cpu among the cpus in group.
 */
static int
find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
{
	unsigned long load, min_load = ULONG_MAX;
	int idlest = -1;
	int i;

	/* Traverse only the allowed CPUs */
	for_each_cpu_and(i, sched_group_cpus(group), tsk_cpus_allowed(p)) {
		load = weighted_cpuload(i);

		if (load < min_load || (load == min_load && i == this_cpu)) {
			min_load = load;
			idlest = i;
		}
	}

	return idlest;
}

/*
 * Try and locate an idle CPU in the sched_domain.
 */
static int select_idle_sibling(struct task_struct *p, int target)
{
	int cpu = smp_processor_id();
	int prev_cpu = task_cpu(p);
	struct sched_domain *sd;
	struct sched_group *sg;
	int i;

	/*
	 * If the task is going to be woken-up on this cpu and if it is
	 * already idle, then it is the right target.
	 */
	if (target == cpu && idle_cpu(cpu))
		return cpu;

	/*
	 * If the task is going to be woken-up on the cpu where it previously
	 * ran and if it is currently idle, then it the right target.
	 */
	if (target == prev_cpu && idle_cpu(prev_cpu))
		return prev_cpu;

	/*
	 * Otherwise, iterate the domains and find an elegible idle cpu.
	 */
	sd = rcu_dereference(per_cpu(sd_llc, target));
	for_each_lower_domain(sd) {
		sg = sd->groups;
		do {
			if (!cpumask_intersects(sched_group_cpus(sg),
						tsk_cpus_allowed(p)))
				goto next;

			for_each_cpu(i, sched_group_cpus(sg)) {
				if (!idle_cpu(i))
					goto next;
			}

			target = cpumask_first_and(sched_group_cpus(sg),
					tsk_cpus_allowed(p));
			goto done;
next:
			sg = sg->next;
		} while (sg != sd->groups);
	}
done:
	return target;
}

/*
 * sched_balance_self: balance the current task (running on cpu) in domains
 * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and
 * SD_BALANCE_EXEC.
 *
 * Balance, ie. select the least loaded group.
 *
 * Returns the target CPU number, or the same CPU if no balancing is needed.
 *
 * preempt must be disabled.
 */
static int
select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags)
{
	struct sched_domain *tmp, *affine_sd = NULL, *sd = NULL;
	int cpu = smp_processor_id();
	int prev_cpu = task_cpu(p);
	int new_cpu = cpu;
	int want_affine = 0;
	int want_sd = 1;
	int sync = wake_flags & WF_SYNC;

	if (p->nr_cpus_allowed == 1)
		return prev_cpu;

	if (sd_flag & SD_BALANCE_WAKE) {
		if (cpumask_test_cpu(cpu, tsk_cpus_allowed(p)))
			want_affine = 1;
		new_cpu = prev_cpu;
	}

	rcu_read_lock();
	for_each_domain(cpu, tmp) {
		if (!(tmp->flags & SD_LOAD_BALANCE))
			continue;

		/*
		 * If power savings logic is enabled for a domain, see if we
		 * are not overloaded, if so, don't balance wider.
		 */
		if (tmp->flags & (SD_PREFER_LOCAL)) {
			unsigned long power = 0;
			unsigned long nr_running = 0;
			unsigned long capacity;
			int i;

			for_each_cpu(i, sched_domain_span(tmp)) {
				power += power_of(i);
				nr_running += cpu_rq(i)->cfs.nr_running;
			}

			capacity = DIV_ROUND_CLOSEST(power, SCHED_POWER_SCALE);

			if (nr_running < capacity)
				want_sd = 0;
		}

		/*
		 * If both cpu and prev_cpu are part of this domain,
		 * cpu is a valid SD_WAKE_AFFINE target.
		 */
		if (want_affine && (tmp->flags & SD_WAKE_AFFINE) &&
		    cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) {
			affine_sd = tmp;
			want_affine = 0;
		}

		if (!want_sd && !want_affine)
			break;

		if (!(tmp->flags & sd_flag))
			continue;

		if (want_sd)
			sd = tmp;
	}

	if (affine_sd) {
		if (cpu == prev_cpu || wake_affine(affine_sd, p, sync))
			prev_cpu = cpu;

		new_cpu = select_idle_sibling(p, prev_cpu);
		goto unlock;
	}

	while (sd) {
		int load_idx = sd->forkexec_idx;
		struct sched_group *group;
		int weight;

		if (!(sd->flags & sd_flag)) {
			sd = sd->child;
			continue;
		}

		if (sd_flag & SD_BALANCE_WAKE)
			load_idx = sd->wake_idx;

		group = find_idlest_group(sd, p, cpu, load_idx);
		if (!group) {
			sd = sd->child;
			continue;
		}

		new_cpu = find_idlest_cpu(group, p, cpu);
		if (new_cpu == -1 || new_cpu == cpu) {
			/* Now try balancing at a lower domain level of cpu */
			sd = sd->child;
			continue;
		}

		/* Now try balancing at a lower domain level of new_cpu */
		cpu = new_cpu;
		weight = sd->span_weight;
		sd = NULL;
		for_each_domain(cpu, tmp) {
			if (weight <= tmp->span_weight)
				break;
			if (tmp->flags & sd_flag)
				sd = tmp;
		}
		/* while loop will break here if sd == NULL */
	}
unlock:
	rcu_read_unlock();

	return new_cpu;
}
#endif /* CONFIG_SMP */

static unsigned long
wakeup_gran(struct sched_entity *curr, struct sched_entity *se)
{
	unsigned long gran = sysctl_sched_wakeup_granularity;

	/*
	 * Since its curr running now, convert the gran from real-time
	 * to virtual-time in his units.
	 *
	 * By using 'se' instead of 'curr' we penalize light tasks, so
	 * they get preempted easier. That is, if 'se' < 'curr' then
	 * the resulting gran will be larger, therefore penalizing the
	 * lighter, if otoh 'se' > 'curr' then the resulting gran will
	 * be smaller, again penalizing the lighter task.
	 *
	 * This is especially important for buddies when the leftmost
	 * task is higher priority than the buddy.
	 */
	return calc_delta_fair(gran, se);
}

/*
 * Should 'se' preempt 'curr'.
 *
 *             |s1
 *        |s2
 *   |s3
 *         g
 *      |<--->|c
 *
 *  w(c, s1) = -1
 *  w(c, s2) =  0
 *  w(c, s3) =  1
 *
 */
static int
wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se)
{
	s64 gran, vdiff = curr->vruntime - se->vruntime;

	if (vdiff <= 0)
		return -1;

	gran = wakeup_gran(curr, se);
	if (vdiff > gran)
		return 1;

	return 0;
}

static void set_last_buddy(struct sched_entity *se)
{
	if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE))
		return;

	for_each_sched_entity(se)
		cfs_rq_of(se)->last = se;
}

static void set_next_buddy(struct sched_entity *se)
{
	if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE))
		return;

	for_each_sched_entity(se)
		cfs_rq_of(se)->next = se;
}

static void set_skip_buddy(struct sched_entity *se)
{
	for_each_sched_entity(se)
		cfs_rq_of(se)->skip = se;
}

/*
 * Preempt the current task with a newly woken task if needed:
 */
static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
{
	struct task_struct *curr = rq->curr;
	struct sched_entity *se = &curr->se, *pse = &p->se;
	struct cfs_rq *cfs_rq = task_cfs_rq(curr);
	int scale = cfs_rq->nr_running >= sched_nr_latency;
	int next_buddy_marked = 0;

	if (unlikely(se == pse))
		return;

	/*
	 * This is possible from callers such as move_task(), in which we
	 * unconditionally check_prempt_curr() after an enqueue (which may have
	 * lead to a throttle).  This both saves work and prevents false
	 * next-buddy nomination below.
	 */
	if (unlikely(throttled_hierarchy(cfs_rq_of(pse))))
		return;

	if (sched_feat(NEXT_BUDDY) && scale && !(wake_flags & WF_FORK)) {
		set_next_buddy(pse);
		next_buddy_marked = 1;
	}

	/*
	 * We can come here with TIF_NEED_RESCHED already set from new task
	 * wake up path.
	 *
	 * Note: this also catches the edge-case of curr being in a throttled
	 * group (e.g. via set_curr_task), since update_curr() (in the
	 * enqueue of curr) will have resulted in resched being set.  This
	 * prevents us from potentially nominating it as a false LAST_BUDDY
	 * below.
	 */
	if (test_tsk_need_resched(curr))
		return;

	/* Idle tasks are by definition preempted by non-idle tasks. */
	if (unlikely(curr->policy == SCHED_IDLE) &&
	    likely(p->policy != SCHED_IDLE))
		goto preempt;

	/*
	 * Batch and idle tasks do not preempt non-idle tasks (their preemption
	 * is driven by the tick):
	 */
	if (unlikely(p->policy != SCHED_NORMAL))
		return;

	find_matching_se(&se, &pse);
	update_curr(cfs_rq_of(se));
	BUG_ON(!pse);
	if (wakeup_preempt_entity(se, pse) == 1) {
		/*
		 * Bias pick_next to pick the sched entity that is
		 * triggering this preemption.
		 */
		if (!next_buddy_marked)
			set_next_buddy(pse);
		goto preempt;
	}

	return;

preempt:
	resched_task(curr);
	/*
	 * Only set the backward buddy when the current task is still
	 * on the rq. This can happen when a wakeup gets interleaved
	 * with schedule on the ->pre_schedule() or idle_balance()
	 * point, either of which can * drop the rq lock.
	 *
	 * Also, during early boot the idle thread is in the fair class,
	 * for obvious reasons its a bad idea to schedule back to it.
	 */
	if (unlikely(!se->on_rq || curr == rq->idle))
		return;

	if (sched_feat(LAST_BUDDY) && scale && entity_is_task(se))
		set_last_buddy(se);
}

static struct task_struct *pick_next_task_fair(struct rq *rq)
{
	struct task_struct *p;
	struct cfs_rq *cfs_rq = &rq->cfs;
	struct sched_entity *se;

	if (!cfs_rq->nr_running)
		return NULL;

	do {
		se = pick_next_entity(cfs_rq);
		set_next_entity(cfs_rq, se);
		cfs_rq = group_cfs_rq(se);
	} while (cfs_rq);

	p = task_of(se);
	if (hrtick_enabled(rq))
		hrtick_start_fair(rq, p);

	return p;
}

/*
 * Account for a descheduled task:
 */
static void put_prev_task_fair(struct rq *rq, struct task_struct *prev)
{
	struct sched_entity *se = &prev->se;
	struct cfs_rq *cfs_rq;

	for_each_sched_entity(se) {
		cfs_rq = cfs_rq_of(se);
		put_prev_entity(cfs_rq, se);
	}
}

/*
 * sched_yield() is very simple
 *
 * The magic of dealing with the ->skip buddy is in pick_next_entity.
 */
static void yield_task_fair(struct rq *rq)
{
	struct task_struct *curr = rq->curr;
	struct cfs_rq *cfs_rq = task_cfs_rq(curr);
	struct sched_entity *se = &curr->se;

	/*
	 * Are we the only task in the tree?
	 */
	if (unlikely(rq->nr_running == 1))
		return;

	clear_buddies(cfs_rq, se);

	if (curr->policy != SCHED_BATCH) {
		update_rq_clock(rq);
		/*
		 * Update run-time statistics of the 'current'.
		 */
		update_curr(cfs_rq);
		/*
		 * Tell update_rq_clock() that we've just updated,
		 * so we don't do microscopic update in schedule()
		 * and double the fastpath cost.
		 */
		 rq->skip_clock_update = 1;
	}

	set_skip_buddy(se);
}

static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preempt)
{
	struct sched_entity *se = &p->se;

	/* throttled hierarchies are not runnable */
	if (!se->on_rq || throttled_hierarchy(cfs_rq_of(se)))
		return false;

	/* Tell the scheduler that we'd really like pse to run next. */
	set_next_buddy(se);

	yield_task_fair(rq);

	return true;
}

#ifdef CONFIG_SMP
/**************************************************
 * Fair scheduling class load-balancing methods:
 */

static unsigned long __read_mostly max_load_balance_interval = HZ/10;

#define LBF_ALL_PINNED	0x01
#define LBF_NEED_BREAK	0x02

struct lb_env {
	struct sched_domain	*sd;

	int			src_cpu;
	struct rq		*src_rq;

	int			dst_cpu;
	struct rq		*dst_rq;

	enum cpu_idle_type	idle;
	long			imbalance;
	unsigned int		flags;

	unsigned int		loop;
	unsigned int		loop_break;
	unsigned int		loop_max;
};

/*
 * move_task - move a task from one runqueue to another runqueue.
 * Both runqueues must be locked.
 */
static void move_task(struct task_struct *p, struct lb_env *env)
{
	deactivate_task(env->src_rq, p, 0);
	set_task_cpu(p, env->dst_cpu);
	activate_task(env->dst_rq, p, 0);
	check_preempt_curr(env->dst_rq, p, 0);
}

/*
 * Is this task likely cache-hot:
 */
static int
task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
{
	s64 delta;

	if (p->sched_class != &fair_sched_class)
		return 0;

	if (unlikely(p->policy == SCHED_IDLE))
		return 0;

	/*
	 * Buddy candidates are cache hot:
	 */
	if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running &&
			(&p->se == cfs_rq_of(&p->se)->next ||
			 &p->se == cfs_rq_of(&p->se)->last))
		return 1;

	if (sysctl_sched_migration_cost == -1)
		return 1;
	if (sysctl_sched_migration_cost == 0)
		return 0;

	delta = now - p->se.exec_start;

	return delta < (s64)sysctl_sched_migration_cost;
}

/*
 * can_migrate_task - may task p from runqueue rq be migrated to this_cpu?
 */
static
int can_migrate_task(struct task_struct *p, struct lb_env *env)
{
	int tsk_cache_hot = 0;
	/*
	 * We do not migrate tasks that are:
	 * 1) running (obviously), or
	 * 2) cannot be migrated to this CPU due to cpus_allowed, or
	 * 3) are cache-hot on their current CPU.
	 */
	if (!cpumask_test_cpu(env->dst_cpu, tsk_cpus_allowed(p))) {
		schedstat_inc(p, se.statistics.nr_failed_migrations_affine);
		return 0;
	}
	env->flags &= ~LBF_ALL_PINNED;

	if (task_running(env->src_rq, p)) {
		schedstat_inc(p, se.statistics.nr_failed_migrations_running);
		return 0;
	}

	/*
	 * Aggressive migration if:
	 * 1) task is cache cold, or
	 * 2) too many balance attempts have failed.
	 */

	tsk_cache_hot = task_hot(p, env->src_rq->clock_task, env->sd);
	if (!tsk_cache_hot ||
		env->sd->nr_balance_failed > env->sd->cache_nice_tries) {
#ifdef CONFIG_SCHEDSTATS
		if (tsk_cache_hot) {
			schedstat_inc(env->sd, lb_hot_gained[env->idle]);
			schedstat_inc(p, se.statistics.nr_forced_migrations);
		}
#endif
		return 1;
	}

	if (tsk_cache_hot) {
		schedstat_inc(p, se.statistics.nr_failed_migrations_hot);
		return 0;
	}
	return 1;
}

/*
 * move_one_task tries to move exactly one task from busiest to this_rq, as
 * part of active balancing operations within "domain".
 * Returns 1 if successful and 0 otherwise.
 *
 * Called with both runqueues locked.
 */
static int move_one_task(struct lb_env *env)
{
	struct task_struct *p, *n;

	list_for_each_entry_safe(p, n, &env->src_rq->cfs_tasks, se.group_node) {
		if (throttled_lb_pair(task_group(p), env->src_rq->cpu, env->dst_cpu))
			continue;

		if (!can_migrate_task(p, env))
			continue;

		move_task(p, env);
		/*
		 * Right now, this is only the second place move_task()
		 * is called, so we can safely collect move_task()
		 * stats here rather than inside move_task().
		 */
		schedstat_inc(env->sd, lb_gained[env->idle]);
		return 1;
	}
	return 0;
}

static unsigned long task_h_load(struct task_struct *p);

static const unsigned int sched_nr_migrate_break = 32;

/*
 * move_tasks tries to move up to imbalance weighted load from busiest to
 * this_rq, as part of a balancing operation within domain "sd".
 * Returns 1 if successful and 0 otherwise.
 *
 * Called with both runqueues locked.
 */
static int move_tasks(struct lb_env *env)
{
	struct list_head *tasks = &env->src_rq->cfs_tasks;
	struct task_struct *p;
	unsigned long load;
	int pulled = 0;

	if (env->imbalance <= 0)
		return 0;

	while (!list_empty(tasks)) {
		p = list_first_entry(tasks, struct task_struct, se.group_node);

		env->loop++;
		/* We've more or less seen every task there is, call it quits */
		if (env->loop > env->loop_max)
			break;

		/* take a breather every nr_migrate tasks */
		if (env->loop > env->loop_break) {
			env->loop_break += sched_nr_migrate_break;
			env->flags |= LBF_NEED_BREAK;
			break;
		}

		if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu))
			goto next;

		load = task_h_load(p);

		if (sched_feat(LB_MIN) && load < 16 && !env->sd->nr_balance_failed)
			goto next;

		if ((load / 2) > env->imbalance)
			goto next;

		if (!can_migrate_task(p, env))
			goto next;

		move_task(p, env);
		pulled++;
		env->imbalance -= load;

#ifdef CONFIG_PREEMPT
		/*
		 * NEWIDLE balancing is a source of latency, so preemptible
		 * kernels will stop after the first task is pulled to minimize
		 * the critical section.
		 */
		if (env->idle == CPU_NEWLY_IDLE)
			break;
#endif

		/*
		 * We only want to steal up to the prescribed amount of
		 * weighted load.
		 */
		if (env->imbalance <= 0)
			break;

		continue;
next:
		list_move_tail(&p->se.group_node, tasks);
	}

	/*
	 * Right now, this is one of only two places move_task() is called,
	 * so we can safely collect move_task() stats here rather than
	 * inside move_task().
	 */
	schedstat_add(env->sd, lb_gained[env->idle], pulled);

	return pulled;
}

#ifdef CONFIG_FAIR_GROUP_SCHED
/*
 * update tg->load_weight by folding this cpu's load_avg
 */
static int update_shares_cpu(struct task_group *tg, int cpu)
{
	struct cfs_rq *cfs_rq;
	unsigned long flags;
	struct rq *rq;

	if (!tg->se[cpu])
		return 0;

	rq = cpu_rq(cpu);
	cfs_rq = tg->cfs_rq[cpu];

	raw_spin_lock_irqsave(&rq->lock, flags);

	update_rq_clock(rq);
	update_cfs_load(cfs_rq, 1);

	/*
	 * We need to update shares after updating tg->load_weight in
	 * order to adjust the weight of groups with long running tasks.
	 */
	update_cfs_shares(cfs_rq);

	raw_spin_unlock_irqrestore(&rq->lock, flags);

	return 0;
}

static void update_shares(int cpu)
{
	struct cfs_rq *cfs_rq;
	struct rq *rq = cpu_rq(cpu);

	rcu_read_lock();
	/*
	 * Iterates the task_group tree in a bottom up fashion, see
	 * list_add_leaf_cfs_rq() for details.
	 */
	for_each_leaf_cfs_rq(rq, cfs_rq) {
		/* throttled entities do not contribute to load */
		if (throttled_hierarchy(cfs_rq))
			continue;

		update_shares_cpu(cfs_rq->tg, cpu);
	}
	rcu_read_unlock();
}

/*
 * Compute the cpu's hierarchical load factor for each task group.
 * This needs to be done in a top-down fashion because the load of a child
 * group is a fraction of its parents load.
 */
static int tg_load_down(struct task_group *tg, void *data)
{
	unsigned long load;
	long cpu = (long)data;

	if (!tg->parent) {
		load = cpu_rq(cpu)->load.weight;
	} else {
		load = tg->parent->cfs_rq[cpu]->h_load;
		load *= tg->se[cpu]->load.weight;
		load /= tg->parent->cfs_rq[cpu]->load.weight + 1;
	}

	tg->cfs_rq[cpu]->h_load = load;

	return 0;
}

static void update_h_load(long cpu)
{
	rcu_read_lock();
	walk_tg_tree(tg_load_down, tg_nop, (void *)cpu);
	rcu_read_unlock();
}

static unsigned long task_h_load(struct task_struct *p)
{
	struct cfs_rq *cfs_rq = task_cfs_rq(p);
	unsigned long load;

	load = p->se.load.weight;
	load = div_u64(load * cfs_rq->h_load, cfs_rq->load.weight + 1);

	return load;
}
#else
static inline void update_shares(int cpu)
{
}

static inline void update_h_load(long cpu)
{
}

static unsigned long task_h_load(struct task_struct *p)
{
	return p->se.load.weight;
}
#endif

/********** Helpers for find_busiest_group ************************/
/*
 * sd_lb_stats - Structure to store the statistics of a sched_domain
 * 		during load balancing.
 */
struct sd_lb_stats {
	struct sched_group *busiest; /* Busiest group in this sd */
	struct sched_group *this;  /* Local group in this sd */
	unsigned long total_load;  /* Total load of all groups in sd */
	unsigned long total_pwr;   /*	Total power of all groups in sd */
	unsigned long avg_load;	   /* Average load across all groups in sd */

	/** Statistics of this group */
	unsigned long this_load;
	unsigned long this_load_per_task;
	unsigned long this_nr_running;
	unsigned long this_has_capacity;
	unsigned int  this_idle_cpus;

	/* Statistics of the busiest group */
	unsigned int  busiest_idle_cpus;
	unsigned long max_load;
	unsigned long busiest_load_per_task;
	unsigned long busiest_nr_running;
	unsigned long busiest_group_capacity;
	unsigned long busiest_has_capacity;
	unsigned int  busiest_group_weight;

	int group_imb; /* Is there imbalance in this sd */
};

/*
 * sg_lb_stats - stats of a sched_group required for load_balancing
 */
struct sg_lb_stats {
	unsigned long avg_load; /*Avg load across the CPUs of the group */
	unsigned long group_load; /* Total load over the CPUs of the group */
	unsigned long sum_nr_running; /* Nr tasks running in the group */
	unsigned long sum_weighted_load; /* Weighted load of group's tasks */
	unsigned long group_capacity;
	unsigned long idle_cpus;
	unsigned long group_weight;
	int group_imb; /* Is there an imbalance in the group ? */
	int group_has_capacity; /* Is there extra capacity in the group? */
};

/**
 * get_sd_load_idx - Obtain the load index for a given sched domain.
 * @sd: The sched_domain whose load_idx is to be obtained.
 * @idle: The Idle status of the CPU for whose sd load_icx is obtained.
 */
static inline int get_sd_load_idx(struct sched_domain *sd,
					enum cpu_idle_type idle)
{
	int load_idx;

	switch (idle) {
	case CPU_NOT_IDLE:
		load_idx = sd->busy_idx;
		break;

	case CPU_NEWLY_IDLE:
		load_idx = sd->newidle_idx;
		break;
	default:
		load_idx = sd->idle_idx;
		break;
	}

	return load_idx;
}

unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu)
{
	return SCHED_POWER_SCALE;
}

unsigned long __weak arch_scale_freq_power(struct sched_domain *sd, int cpu)
{
	return default_scale_freq_power(sd, cpu);
}

unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu)
{
	unsigned long weight = sd->span_weight;
	unsigned long smt_gain = sd->smt_gain;

	smt_gain /= weight;

	return smt_gain;
}

unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu)
{
	return default_scale_smt_power(sd, cpu);
}

unsigned long scale_rt_power(int cpu)
{
	struct rq *rq = cpu_rq(cpu);
	u64 total, available, age_stamp, avg;

	/*
	 * Since we're reading these variables without serialization make sure
	 * we read them once before doing sanity checks on them.
	 */
	age_stamp = ACCESS_ONCE(rq->age_stamp);
	avg = ACCESS_ONCE(rq->rt_avg);

	total = sched_avg_period() + (rq->clock - age_stamp);

	if (unlikely(total < avg)) {
		/* Ensures that power won't end up being negative */
		available = 0;
	} else {
		available = total - avg;
	}

	if (unlikely((s64)total < SCHED_POWER_SCALE))
		total = SCHED_POWER_SCALE;

	total >>= SCHED_POWER_SHIFT;

	return div_u64(available, total);
}

static void update_cpu_power(struct sched_domain *sd, int cpu)
{
	unsigned long weight = sd->span_weight;
	unsigned long power = SCHED_POWER_SCALE;
	struct sched_group *sdg = sd->groups;

	if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) {
		if (sched_feat(ARCH_POWER))
			power *= arch_scale_smt_power(sd, cpu);
		else
			power *= default_scale_smt_power(sd, cpu);

		power >>= SCHED_POWER_SHIFT;
	}

	sdg->sgp->power_orig = power;

	if (sched_feat(ARCH_POWER))
		power *= arch_scale_freq_power(sd, cpu);
	else
		power *= default_scale_freq_power(sd, cpu);

	power >>= SCHED_POWER_SHIFT;

	power *= scale_rt_power(cpu);
	power >>= SCHED_POWER_SHIFT;

	if (!power)
		power = 1;

	cpu_rq(cpu)->cpu_power = power;
	sdg->sgp->power = power;
}

void update_group_power(struct sched_domain *sd, int cpu)
{
	struct sched_domain *child = sd->child;
	struct sched_group *group, *sdg = sd->groups;
	unsigned long power;
	unsigned long interval;

	interval = msecs_to_jiffies(sd->balance_interval);
	interval = clamp(interval, 1UL, max_load_balance_interval);
	sdg->sgp->next_update = jiffies + interval;

	if (!child) {
		update_cpu_power(sd, cpu);
		return;
	}

	power = 0;

	if (child->flags & SD_OVERLAP) {
		/*
		 * SD_OVERLAP domains cannot assume that child groups
		 * span the current group.
		 */

		for_each_cpu(cpu, sched_group_cpus(sdg))
			power += power_of(cpu);
	} else  {
		/*
		 * !SD_OVERLAP domains can assume that child groups
		 * span the current group.
		 */ 

		group = child->groups;
		do {
			power += group->sgp->power;
			group = group->next;
		} while (group != child->groups);
	}

	sdg->sgp->power_orig = sdg->sgp->power = power;
}

/*
 * Try and fix up capacity for tiny siblings, this is needed when
 * things like SD_ASYM_PACKING need f_b_g to select another sibling
 * which on its own isn't powerful enough.
 *
 * See update_sd_pick_busiest() and check_asym_packing().
 */
static inline int
fix_small_capacity(struct sched_domain *sd, struct sched_group *group)
{
	/*
	 * Only siblings can have significantly less than SCHED_POWER_SCALE
	 */
	if (!(sd->flags & SD_SHARE_CPUPOWER))
		return 0;

	/*
	 * If ~90% of the cpu_power is still there, we're good.
	 */
	if (group->sgp->power * 32 > group->sgp->power_orig * 29)
		return 1;

	return 0;
}

/**
 * update_sg_lb_stats - Update sched_group's statistics for load balancing.
 * @env: The load balancing environment.
 * @group: sched_group whose statistics are to be updated.
 * @load_idx: Load index of sched_domain of this_cpu for load calc.
 * @local_group: Does group contain this_cpu.
 * @cpus: Set of cpus considered for load balancing.
 * @balance: Should we balance.
 * @sgs: variable to hold the statistics for this group.
 */