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* Add a new deferrable delayed work initVenki Pallipadi2007-05-08
| | | | | | | | | | | | | | Add a new deferrable delayed work init. This can be used to schedule work that are 'unimportant' when CPU is idle and can be called later, when CPU eventually comes out of idle. Use this init in cpufreq ondemand governor. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [CPUFREQ] cleanup kconfig optionsMike Frysinger2007-04-26
| | | | | | | | Adds proper lines to help output of kconfig so people can find the module names. Also fixed some broken leading spaces versus tabs. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] Remove deprecated /proc/acpi/processor/performance write supportThomas Renninger2007-04-26
| | | | | | | | | | Remove deprecated /proc/acpi/processor/performance write support Writing to /proc/acpi/processor/xy/performance interferes with sysfs cpufreq interface. Also removes buggy cpufreq_set_policy exported symbol. Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] Fix limited cpufreq when booted on batteryThomas Renninger2007-04-26
| | | | | | | | | | | | | | | | | | References: https://bugzilla.novell.com/show_bug.cgi?id=231107 https://bugzilla.novell.com/show_bug.cgi?id=264077 Fix limited cpufreq when booted on battery If booted on battery: cpufreq_set_policy (evil) is invoked which calls verify_within_limits. max_freq gets lowered and therefore users_policy.max, which is used to restore higher freqs via update_policy later is set to the already limited frequency -> you can never go up again, even BIOS allows higher freqs later. Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>
* [PATCH] Fix maxcpus=1 trigerring BUG() in cpufreqVenki Pallipadi2007-03-27
| | | | | | | | | | | | Ingo reported it on lkml in the thread "2.6.21-rc5: maxcpus=1 crash in cpufreq: kernel BUG at drivers/cpufreq/cpufreq.c:82!" This check added to remove_dev is symmetric to one in add_dev and handles callbacks for offline cpus cleanly. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Revert "[CPUFREQ] constify cpufreq_driver where possible."Linus Torvalds2007-02-26
| | | | | | | | | | This reverts commit aeeddc1435c37fa3fc844f31d39c185b08de4158, which was half-baked and broken. It just resulted in compile errors, since cpufreq_register_driver() still changes the 'driver_data' by setting bits in the flags field. So claiming it is 'const' _really_ doesn't work. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreqLinus Torvalds2007-02-26
|\ | | | | | | | | | | | | | | | | | | * master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq: [CPUFREQ] constify some data tables. [CPUFREQ] constify cpufreq_driver where possible. {rd,wr}msr_on_cpu SMP=n optimization [CPUFREQ] cpufreq_ondemand.c: don't use _WORK_NAR rdmsr_on_cpu, wrmsr_on_cpu [CPUFREQ] Revert default on deprecated config X86_SPEEDSTEP_CENTRINO_ACPI
| * [CPUFREQ] constify cpufreq_driver where possible.Dave Jones2007-02-22
| | | | | | | | | | | | | | Not all cases are possible due to ->flags being set at runtime on some drivers. Signed-off-by: Dave Jones <davej@redhat.com>
| * [CPUFREQ] cpufreq_ondemand.c: don't use _WORK_NAROleg Nesterov2007-02-20
| | | | | | | | | | | | | | | | | | Looks like dbs_timer() is very careful wrt per_cpu(cpu_dbs_info), and it doesn't need the help of WORK_STRUCT_NOAUTOREL. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-By: David Howells <dhowells@redhat.com> Signed-off-by: Dave Jones <davej@redhat.com>
* | Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreqLinus Torvalds2007-02-16
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq: [CPUFREQ] Longhaul - Redo Longhaul ver. 2 [CPUFREQ] EPS - Correct 2nd brand test [CPUFREQ] Longhaul - Separate frequency and voltage transition [CPUFREQ] Longhaul - Models of Nehemiah [CPUFREQ] Whitespace fixup [CPUFREQ] Longhaul - Simplier minmult [CPUFREQ] CPU_FREQ_TABLE shouldn't be a def_tristate [CPUFREQ] ondemand governor use new cpufreq rwsem locking in work callback [CPUFREQ] ondemand governor restructure the work callback [CPUFREQ] Rewrite lock in cpufreq to eliminate cpufreq/hotplug related issues [CPUFREQ] Remove hotplug cpu crap [CPUFREQ] Enhanced PowerSaver driver [CPUFREQ] Longhaul - Add VT8235 support [CPUFREQ] Longhaul - Fix guess_fsb function [CPUFREQ] Longhaul - Remove duplicate tables [CPUFREQ] Longhaul - Introduce Nehemiah C [CPUFREQ] fix cpuinfo_cur_freq for CPU_HW_PSTATE [CPUFREQ] Longhaul - Remove "ignore_latency" option
| * [CPUFREQ] Whitespace fixupDave Jones2007-02-10
| | | | | | | | Signed-off-by: Dave Jones <davej@redhat.com>
| * [CPUFREQ] CPU_FREQ_TABLE shouldn't be a def_tristateAdrian Bunk2007-02-10
| | | | | | | | | | | | | | | | | | | | CPU_FREQ_TABLE enables helper code and gets select'ed when it's required. Building it as a module when it's not required doesn't seem to make much sense. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Jones <davej@redhat.com>
| * [CPUFREQ] ondemand governor use new cpufreq rwsem locking in work callbackVenkatesh Pallipadi2007-02-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Eliminate flush_workqueue in cpufreq_governor(STOP) callpath. Using flush there has a deadlock potential as in http://uwsg.iu.edu/hypermail/linux/kernel/0611.3/1223.html Also, cleanup the locking issues with do_dbs_timer delayed_work callback. As it changes the CPU frequency using __cpufreq_target, it needs to have policy_rwsem in write mode, which also protects it from hot plug. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Jones <davej@redhat.com>
| * [CPUFREQ] ondemand governor restructure the work callbackVenkatesh Pallipadi2007-02-10
| | | | | | | | | | | | | | | | | | | | | | | | | | Restructure the delayed_work callback in ondemand. This eliminates the need for smp_processor_id in the callback function and also helps in proper locking and avoiding flush_workqueue when stopping the governor (done in subsequent patch). Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Jones <davej@redhat.com>
| * [CPUFREQ] Rewrite lock in cpufreq to eliminate cpufreq/hotplug related issuesVenkatesh Pallipadi2007-02-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Yet another attempt to resolve cpufreq and hotplug locking issues. Patchset has 3 patches: * Rewrite the lock infrastructure of cpufreq using a per cpu rwsem. * Minor restructuring of work callback in ondemand driver. * Use the new cpufreq rwsem infrastructure in ondemand work. This patch: Convert policy->lock to rwsem and move it to per_cpu area. This rwsem will protect against both changing/accessing policy related parameters and CPU hot plug/unplug. [malattia@linux.it: fix oops in kref_put()] Cc: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Mattia Dongili <malattia@linux.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Jones <davej@redhat.com>
| * [CPUFREQ] Remove hotplug cpu crapDave Jones2007-02-10
| | | | | | | | | | | | | | | | | | The hotplug CPU locking in cpufreq is horrendous. No-one seems to care enough to fix it, so just remove it so that the 99.9% of the real world users of this code can use cpufreq without being bothered by warnings. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Jones <davej@redhat.com>
* | [PATCH] remove many unneeded #includes of sched.hTim Schmielau2007-02-14
|/ | | | | | | | | | | | | | | | | | | | | | | | After Al Viro (finally) succeeded in removing the sched.h #include in module.h recently, it makes sense again to remove other superfluous sched.h includes. There are quite a lot of files which include it but don't actually need anything defined in there. Presumably these includes were once needed for macros that used to live in sched.h, but moved to other header files in the course of cleaning it up. To ease the pain, this time I did not fiddle with any header files and only removed #includes from .c-files, which tend to cause less trouble. Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha, arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig, allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all configs in arch/arm/configs on arm. I also checked that no new warnings were introduced by the patch (actually, some warnings are removed that were emitted by unnecessarily included header files). Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [CPUFREQ] check sysfs_create_link return valueAhmed S. Darwish2007-01-29
| | | | | | | | Trivial patch to check sysfs_create_link return values. Fail gracefully if needed. Signed-off-by: Ahmed Darwish <darwish.07@gmail.com> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] Bug fix for acpi-cpufreq and cpufreq_stats oops on frequency ↵Venkatesh Pallipadi2006-12-22
| | | | | | | | | | | | | | | | | | | | | change notification Fixes the oops in cpufreq_stats with acpi_cpufreq driver. The issue was that the frequency was reported as 0 in acpi-cpufreq.c. The bug is due to different indicies for freq_table and ACPI perf table. Also adds a check in cpufreq_stats to check for error return from freq_table_get_index() and avoid using the error return value. Patch fixes the issue reported at http://www.ussg.iu.edu/hypermail/linux/kernel/0611.2/0629.html and also other similar issue here http://bugme.osdl.org/show_bug.cgi?id=7383 comment 53 Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] fixes typo in cpufreq.cDhaval Giani2006-12-13
| | | | | | | This patch fixes a typo in cpufreq.c From: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Dave Jones <davej@redhat.com>
* Merge ../linusDave Jones2006-12-12
|\ | | | | | | | | | | Conflicts: drivers/cpufreq/cpufreq.c
| * [PATCH] hotplug CPU: clean up hotcpu_notifier() useIngo Molnar2006-12-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There was lots of #ifdef noise in the kernel due to hotcpu_notifier(fn, prio) not correctly marking 'fn' as used in the !HOTPLUG_CPU case, and thus generating compiler warnings of unused symbols, hence forcing people to add #ifdefs. the compiler can skip truly unused functions just fine: text data bss dec hex filename 1624412 728710 3674856 6027978 5bfaca vmlinux.before 1624412 728710 3674856 6027978 5bfaca vmlinux.after [akpm@osdl.org: topology.c fix] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| * WorkStruct: make allyesconfigDavid Howells2006-11-22
| | | | | | | | | | | | Fix up for make allyesconfig. Signed-Off-By: David Howells <dhowells@redhat.com>
| * WorkStruct: Pass the work_struct pointer instead of context dataDavid Howells2006-11-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pass the work_struct pointer to the work function rather than context data. The work function can use container_of() to work out the data. For the cases where the container of the work_struct may go away the moment the pending bit is cleared, it is made possible to defer the release of the structure by deferring the clearing of the pending bit. To make this work, an extra flag is introduced into the management side of the work_struct. This governs auto-release of the structure upon execution. Ordinarily, the work queue executor would release the work_struct for further scheduling or deallocation by clearing the pending bit prior to jumping to the work function. This means that, unless the driver makes some guarantee itself that the work_struct won't go away, the work function may not access anything else in the work_struct or its container lest they be deallocated.. This is a problem if the auxiliary data is taken away (as done by the last patch). However, if the pending bit is *not* cleared before jumping to the work function, then the work function *may* access the work_struct and its container with no problems. But then the work function must itself release the work_struct by calling work_release(). In most cases, automatic release is fine, so this is the default. Special initiators exist for the non-auto-release case (ending in _NAR). Signed-Off-By: David Howells <dhowells@redhat.com>
| * [PATCH] Fix CPU_FREQ_GOV_ONDEMAND=y compile errorDave Jones2006-11-21
| | | | | | | | | | | | | | | | The ONDEMAND governor needs FREQ_TABLE Signed-off-by: Mattia Dongili <malattia@linux.it> Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| * Add "pure_initcall" for static variable initializationLinus Torvalds2006-11-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a quick hack to overcome the fact that SRCU currently does not allow static initializers, and we need to sometimes initialize those things before any other initializers (even "core" ones) can do so. Currently we don't allow this at all for modules, and the only user that needs is right now is cpufreq. As reported by Thomas Gleixner: "Commit b4dfdbb3c707474a2254c5b4d7e62be31a4b7da9 ("[PATCH] cpufreq: make the transition_notifier chain use SRCU breaks cpu frequency notification users, which register the callback > on core_init level." Cc: Thomas Gleixner <tglx@timesys.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Andrew Morton <akpm@osdl.org>, Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [CPUFREQ] Fix coding style issues in cpufreq.Gautham R Shenoy2006-11-06
| | | | | | | | | | | | | | | | Clean up cpufreq subsystem to fix coding style issues and to improve the readability. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Dave Jones <davej@redhat.com>
* | [CPUFREQ] handle sysfs errorsJeff Garzik2006-10-21
| | | | | | | | | | | | Signed-off-by: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Dave Jones <davej@redhat.com>
* | [CPUFREQ][8/8] acpi-cpufreq: Add support for freq feedback from hardwareVenkatesh Pallipadi2006-10-15
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enable ondemand governor and acpi-cpufreq to use IA32_APERF and IA32_MPERF MSR to get active frequency feedback for the last sampling interval. This will make ondemand take right frequency decisions when hardware coordination of frequency is going on. Without APERF/MPERF, ondemand can take wrong decision at times due to underlying hardware coordination or TM2. Example: * CPU 0 and CPU 1 are hardware cooridnated. * CPU 1 running at highest frequency. * CPU 0 was running at highest freq. Now ondemand reduces it to some intermediate frequency based on utilization. * Due to underlying hardware coordination with other CPU 1, CPU 0 continues to run at highest frequency (as long as other CPU is at highest). * When ondemand samples CPU 0 again next time, without actual frequency feedback from APERF/MPERF, it will think that previous frequency change was successful and can go to wrong target frequency. This is because it thinks that utilization it has got this sampling interval is when running at intermediate frequency, rather than actual highest frequency. More information about IA32_APERF IA32_MPERF MSR: Refer to IA-32 Intel® Architecture Software Developer's Manual at http://developer.intel.com Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
* [PATCH] cpufreq: make the transition_notifier chain use SRCUAlan Stern2006-10-04
| | | | | | | | | | | | | | | | | | | | | | This patch (as762) changes the cpufreq_transition_notifier_list from a blocking_notifier_head to an srcu_notifier_head. This will prevent errors caused attempting to call down_read() to access the notifier chain at a time when interrupts must remain disabled, during system suspend. It's not clear to me whether this is really necessary; perhaps the chain could be made into an atomic_notifier. However a couple of the callout routines do use blocking operations, so this approach seems safer. The head of the notifier chain needs to be initialized before use; this is done by an __init routine at core_initcall time. If this turns out not to be a good choice, it can easily be changed. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Jesse Brandeburg <jesse.brandeburg@gmail.com> Cc: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [CPUFREQ] Fix cut-n-paste bug in suspend printkDave Jones2006-09-26
| | | | Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] Fix some more CPU hotplug locking.Dave Jones2006-09-22
| | | | | | | | | | | | | | | | | | | | | | | Lukewarm IQ detected in hotplug locking BUG: warning at kernel/cpu.c:38/lock_cpu_hotplug() [<b0134a42>] lock_cpu_hotplug+0x42/0x65 [<b02f8af1>] cpufreq_update_policy+0x25/0xad [<b0358756>] kprobe_flush_task+0x18/0x40 [<b0355aab>] schedule+0x63f/0x68b [<b01377c2>] __link_module+0x0/0x1f [<b0119e7d>] __cond_resched+0x16/0x34 [<b03560bf>] cond_resched+0x26/0x31 [<b0355b0e>] wait_for_completion+0x17/0xb1 [<f965c547>] cpufreq_stat_cpu_callback+0x13/0x20 [cpufreq_stats] [<f9670074>] cpufreq_stats_init+0x74/0x8b [cpufreq_stats] [<b0137872>] sys_init_module+0x91/0x174 [<b0102c81>] sysenter_past_esp+0x56/0x79 As there are other places that call cpufreq_update_policy without the hotplug lock, it seems better to keep the hotplug locking at the lower level for the time being until this is revamped. Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] Fix sparse warning in ondemandDave Jones2006-09-05
| | | | | | drivers/cpufreq/cpufreq_ondemand.c:323:2: warning: Using plain integer as NULL pointer Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] make drivers/cpufreq/cpufreq_ondemand.c:powersave_bias_target() staticAdrian Bunk2006-08-14
| | | | | | | This patch makes the needlessly global powersave_bias_target() static. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ][2/2] ondemand: updated add powersave_bias tunableAlexey Starikovskiy2006-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ondemand selects the minimum frequency that can retire a workload with negligible idle time -- ideally resulting in the highest performance/power efficiency with negligible performance impact. But on some systems and some workloads, this algorithm is more performance biased than necessary, and de-tuning it a bit to allow some performance impact can save measurable power. This patch adds a "powersave_bias" tunable to ondemand to allow it to reduce its target frequency by a specified percent. By default, the powersave_bias is 0 and has no effect. powersave_bias is in units of 0.1%, so it has an effective range of 1 through 1000, resulting in 0.1% to 100% impact. In practice, users will not be able to detect a difference between 0.1% increments, but 1.0% increments turned out to be too large. Also, the max value of 1000 (100%) would simply peg the system in its deepest power saving P-state, unless the processor really has a hardware P-state at 0Hz:-) For example, If ondemand requests 2.0GHz based on utilization, and powersave_bias=100, this code will knock 10% off the target and seek a target of 1.8GHz instead of 2.0GHz until the next sampling. If 1.8 is an exact match with an hardware frequency we use it, otherwise we average our time between the frequency next higher than 1.8 and next lower than 1.8. Note that a user or administrative program can change powersave_bias at run-time depending on how they expect the system to be used. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi at intel.com> Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy at intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ][1/2] ondemand: updated tune for hardware coordinationAlexey Starikovskiy2006-08-11
| | | | | | | | | Try to make dbs_check_cpu() call on all CPUs at the same jiffy. This will help when multiple cores share P-states via Hardware Coordination. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi at intel.com> Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy at intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] Fix typo.Dave Jones2006-08-11
| | | | Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] [2/2] demand load governor modules.Jeremy Fitzhardinge2006-07-31
| | | | | | | Demand-load cpufreq governor modules if needed. Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] [1/2] add __find_governor helper and clean up some error handling.Jeremy Fitzhardinge2006-07-31
| | | | | | | | | Adds a __find_governor() helper function to look up a governor by name. Also restructures some error handling to conform to the "single-exit" model which is generally preferred for kernel code. Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] return error when failing to set minfreqMattia Dongili2006-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I just stumbled on this bug/feature, this is how to reproduce it: # echo 450000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq # echo 450000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq # echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor # cpufreq-info -p 450000 450000 powersave # echo 1800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq ; echo $? 0 # cpufreq-info -p 450000 450000 powersave Here it is. The kernel refuses to set a min_freq higher than the max_freq but it allows a max_freq lower than min_freq (lowering min_freq also). This behaviour is pretty straightforward (but undocumented) and it doesn't return an error altough failing to accomplish the requested action (set min_freq). The problem (IMO) is basically that userspace is not allowed to set a full policy atomically while the kernel always does that thus it must enforce an ordering on operations. The attached patch returns -EINVAL if trying to increase frequencies starting from scaling_min_freq and documents the correct ordering of writes. Signed-off-by: Mattia Dongili <malattia@linux.it> Signed-off-by: Dominik Brodowski <linux at dominikbrodowski.net> Signed-off-by: Dave Jones <davej@redhat.com> --
* [PATCH] Reorganize the cpufreq cpu hotplug locking to not be totally bizareArjan van de Ven2006-07-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The patch below moves the cpu hotplugging higher up in the cpufreq layering; this is needed to avoid recursive taking of the cpu hotplug lock and to otherwise detangle the mess. The new rules are: 1. you must do lock_cpu_hotplug() around the following functions: __cpufreq_driver_target __cpufreq_governor (for CPUFREQ_GOV_LIMITS operation only) __cpufreq_set_policy 2. governer methods (.governer) must NOT take the lock_cpu_hotplug() lock in any way; they are called with the lock taken already 3. if your governer spawns a thread that does things, like calling __cpufreq_driver_target, your thread must honor rule #1. 4. the policy lock and other cpufreq internal locks nest within the lock_cpu_hotplug() lock. I'm not entirely happy about how the __cpufreq_governor rule ended up (conditional locking rule depending on the argument) but basically all callers pass this as a constant so it's not too horrible. The patch also removes the cpufreq_governor() function since during the locking audit it turned out to be entirely unused (so no need to fix it) The patch works on my testbox, but it could use more testing (otoh... it can't be much worse than the current code) Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [cpufreq] ondemand: make shutdown sequence more robustLinus Torvalds2006-07-23
| | | | | | | | | | | Shutting down the ondemand policy was fraught with potential problems, causing issues for SMP suspend (which wants to hot- unplug) all but the last CPU. This should fix at least the worst problems (divide-by-zero and infinite wait for the workqueue to shut down). Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Fix cpufreq vs hotplug lockdep recursion.Dave Jones2006-07-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | [ There's some not quite baked bits in cpufreq-git right now so sending this on as a patch instead ] On Thu, 2006-07-06 at 07:58 -0700, Tom London wrote: > After installing .2356 I get this each time I boot: > ======================================================= > [ INFO: possible circular locking dependency detected ] > ------------------------------------------------------- > S06cpuspeed/1620 is trying to acquire lock: > (dbs_mutex){--..}, at: [<c060d6bb>] mutex_lock+0x21/0x24 > > but task is already holding lock: > (cpucontrol){--..}, at: [<c060d6bb>] mutex_lock+0x21/0x24 > > which lock already depends on the new lock. > make sure the cpu hotplug recursive mutex (yuck) is taken early in the cpufreq codepaths to avoid a AB-BA deadlock. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreqLinus Torvalds2006-07-04
|\ | | | | | | | | | | | | | | | | * master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq: Move workqueue exports to where the functions are defined. [CPUFREQ] Misc cleanups in ondemand. [CPUFREQ] Make ondemand sampling per CPU and remove the mutex usage in sampling path. [CPUFREQ] Add queue_delayed_work_on() interface for workqueues. [CPUFREQ] Remove slowdown from ondemand sampling path.
| * [CPUFREQ] Misc cleanups in ondemand.Venkatesh Pallipadi2006-06-30
| | | | | | | | | | | | | | | | | | Misc cleanups in ondemand. Should have zero functional impact. Also adding Alexey as author. Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
| * [CPUFREQ] Make ondemand sampling per CPU and remove the mutex usage in ↵Venkatesh Pallipadi2006-06-30
| | | | | | | | | | | | | | | | | | | | sampling path. Make ondemand sampling per CPU and remove the mutex usage in sampling path. Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
| * [CPUFREQ] Remove slowdown from ondemand sampling path.Venkatesh Pallipadi2006-06-30
| | | | | | | | | | | | | | | | | | | | | | Remove slowdown from ondemand sampling path. This reduces the code path length in dbs_check_cpu() by half. slowdown was not used by ondemand by default. If there are any user level tools that were using this tunable, they may report error now. Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
* | Remove obsolete #include <linux/config.h>Jörn Engel2006-06-30
|/ | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PATCH] cpu hotplug: make cpu_notifier related notifier blocks __cpuinit onlyChandra Seetharaman2006-06-27
| | | | | | | | | | | | Make notifier_blocks associated with cpu_notifier as __cpuinitdata. __cpuinitdata makes sure that the data is init time only unless CONFIG_HOTPLUG_CPU is defined. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] cpu hotplug: make [un]register_cpu_notifier init time onlyChandra Seetharaman2006-06-27
| | | | | | | | | | | | | | | | CPUs come online only at init time (unless CONFIG_HOTPLUG_CPU is defined). So, cpu_notifier functionality need to be available only at init time. This patch makes register_cpu_notifier() available only at init time, unless CONFIG_HOTPLUG_CPU is defined. This patch exports register_cpu_notifier() and unregister_cpu_notifier() only if CONFIG_HOTPLUG_CPU is defined. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-19 01:32:34 -0500