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* powerpc/smp: Wait until secondaries are active & onlineMichael Ellerman2015-03-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Anton has a busy ppc64le KVM box where guests sometimes hit the infamous "kernel BUG at kernel/smpboot.c:134!" issue during boot: BUG_ON(td->cpu != smp_processor_id()); Basically a per CPU hotplug thread scheduled on the wrong CPU. The oops output confirms it: CPU: 0 Comm: watchdog/130 The problem is that we aren't ensuring the CPU active bit is set for the secondary before allowing the master to continue on. The master unparks the secondary CPU's kthreads and the scheduler looks for a CPU to run on. It calls select_task_rq() and realises the suggested CPU is not in the cpus_allowed mask. It then ends up in select_fallback_rq(), and since the active bit isnt't set we choose some other CPU to run on. This seems to have been introduced by 6acbfb96976f "sched: Fix hotplug vs. set_cpus_allowed_ptr()", which changed from setting active before online to setting active after online. However that was in turn fixing a bug where other code assumed an active CPU was also online, so we can't just revert that fix. The simplest fix is just to spin waiting for both active & online to be set. We already have a barrier prior to set_cpu_online() (which also sets active), to ensure all other setup is completed before online & active are set. Fixes: 6acbfb96976f ("sched: Fix hotplug vs. set_cpus_allowed_ptr()") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* Merge tag 'powerpc-3.20-1' of ↵Linus Torvalds2015-02-11
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux Pull powerpc updates from Michael Ellerman: - Update of all defconfigs - Addition of a bunch of config options to modernise our defconfigs - Some PS3 updates from Geoff - Optimised memcmp for 64 bit from Anton - Fix for kprobes that allows 'perf probe' to work from Naveen - Several cxl updates from Ian & Ryan - Expanded support for the '24x7' PMU from Cody & Sukadev - Freescale updates from Scott: "Highlights include 8xx optimizations, some more work on datapath device tree content, e300 machine check support, t1040 corenet error reporting, and various cleanups and fixes" * tag 'powerpc-3.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (102 commits) cxl: Add missing return statement after handling AFU errror cxl: Fail AFU initialisation if an invalid configuration record is found cxl: Export optional AFU configuration record in sysfs powerpc/mm: Warn on flushing tlb page in kernel context powerpc/powernv: Add OPAL soft-poweroff routine powerpc/perf/hv-24x7: Document sysfs event description entries powerpc/perf/hv-gpci: add the remaining gpci requests powerpc/perf/{hv-gpci, hv-common}: generate requests with counters annotated powerpc/perf/hv-24x7: parse catalog and populate sysfs with events perf: define EVENT_DEFINE_RANGE_FORMAT_LITE helper perf: add PMU_EVENT_ATTR_STRING() helper perf: provide sysfs_show for struct perf_pmu_events_attr powerpc/kernel: Avoid initializing device-tree pointer twice powerpc: Remove old compile time disabled syscall tracing code powerpc/kernel: Make syscall_exit a local label cxl: Fix device_node reference counting powerpc/mm: bail out early when flushing TLB page powerpc: defconfigs: add MTD_SPI_NOR (new dependency for M25P80) perf/powerpc: reset event hw state when adding it to the PMU powerpc/qe: Use strlcpy() ...
| * powerpc: Remove some unused functionsMichael Ellerman2015-01-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove slice_set_psize() which is not used. It was added in 3a8247cc2c85 "powerpc: Only demote individual slices rather than whole process" but was never used. Remove vsx_assist_exception() which is not used. It was added in ce48b2100785 "powerpc: Add VSX context save/restore, ptrace and signal support" but was never used. Remove generic_mach_cpu_die() which is not used. Its last caller was removed in 375f561a4131 "powerpc/powernv: Always go into nap mode when CPU is offline". Remove mpc7448_hpc2_power_off() and mpc7448_hpc2_halt() which are unused. These were introduced in c5d56332fd6c "[POWERPC] Add general support for mpc7448hpc2 (Taiga) platform" but were never used. This was partially found by using a static code analysis program called cppcheck. Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se> [mpe: Update changelog with details on when/why they are unused] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | Revert "powerpc: Secondary CPUs must set cpu_callin_map after setting active ↵Michael Ellerman2014-12-28
|/ | | | | | | | | | | | and online" This reverts commit 7c5c92ed56d932b2c19c3f8aea86369509407d33. Although this did fix the bug it was aimed at, it also broke secondary startup on platforms that use give/take_timebase(). Unfortunately we didn't detect that while it was in next. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc: Secondary CPUs must set cpu_callin_map after setting active and onlineAnton Blanchard2014-12-09
| | | | | | | | | | | | | | | | | | | | | | | | I have a busy ppc64le KVM box where guests sometimes hit the infamous "kernel BUG at kernel/smpboot.c:134!" issue during boot: BUG_ON(td->cpu != smp_processor_id()); Basically a per CPU hotplug thread scheduled on the wrong CPU. The oops output confirms it: CPU: 0 Comm: watchdog/130 The problem is that we aren't ensuring the CPU active and online bits are set before allowing the master to continue on. The master unparks the secondary CPUs kthreads and the scheduler looks for a CPU to run on. It calls select_task_rq and realises the suggested CPU is not in the cpus_allowed mask. It then ends up in select_fallback_rq, and since the active and online bits aren't set we choose some other CPU to run on. Cc: stable@vger.kernel.org Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc: Replace __get_cpu_var usesChristoph Lameter2014-11-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This still has not been merged and now powerpc is the only arch that does not have this change. Sorry about missing linuxppc-dev before. V2->V2 - Fix up to work against 3.18-rc1 __get_cpu_var() is used for multiple purposes in the kernel source. One of them is address calculation via the form &__get_cpu_var(x). This calculates the address for the instance of the percpu variable of the current processor based on an offset. Other use cases are for storing and retrieving data from the current processors percpu area. __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment. __get_cpu_var() is defined as : __get_cpu_var() always only does an address determination. However, store and retrieve operations could use a segment prefix (or global register on other platforms) to avoid the address calculation. this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use optimized assembly code to read and write per cpu variables. This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr() or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided and less registers are used when code is generated. At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too. The patch set includes passes over all arches as well. Once these operations are used throughout then specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by f.e. using a global register that may be set to the per cpu base. Transformations done to __get_cpu_var() 1. Determine the address of the percpu instance of the current processor. DEFINE_PER_CPU(int, y); int *x = &__get_cpu_var(y); Converts to int *x = this_cpu_ptr(&y); 2. Same as #1 but this time an array structure is involved. DEFINE_PER_CPU(int, y[20]); int *x = __get_cpu_var(y); Converts to int *x = this_cpu_ptr(y); 3. Retrieve the content of the current processors instance of a per cpu variable. DEFINE_PER_CPU(int, y); int x = __get_cpu_var(y) Converts to int x = __this_cpu_read(y); 4. Retrieve the content of a percpu struct DEFINE_PER_CPU(struct mystruct, y); struct mystruct x = __get_cpu_var(y); Converts to memcpy(&x, this_cpu_ptr(&y), sizeof(x)); 5. Assignment to a per cpu variable DEFINE_PER_CPU(int, y) __get_cpu_var(y) = x; Converts to __this_cpu_write(y, x); 6. Increment/Decrement etc of a per cpu variable DEFINE_PER_CPU(int, y); __get_cpu_var(y)++ Converts to __this_cpu_inc(y) Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> Signed-off-by: Christoph Lameter <cl@linux.com> [mpe: Fix build errors caused by set/or_softirq_pending(), and rework assignment in __set_breakpoint() to use memcpy().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc: Only set numa node information for present cpus at boottimeLi Zhong2014-09-25
| | | | | | | | | | | | | | | | | | | | As Nish suggested, it makes more sense to init the numa node informatiion for present cpus at boottime, which could also avoid WARN_ON(1) in numa_setup_cpu(). With this change, we also need to change the smp_prepare_cpus() to set up numa information only on present cpus. For those possible, but not present cpus, their numa information will be set up after they are started, as the original code did before commit 2fabf084b6ad. Cc: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Acked-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> Tested-by: Cyril Bur <cyril.bur@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc: Ensure global functions include their prototypeAnton Blanchard2014-09-25
| | | | | | | | Fix a number of places where global functions were not including their prototype. This ensures the prototype and the function match. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc: reorder per-cpu NUMA information's initializationNishanth Aravamudan2014-08-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is an issue currently where NUMA information is used on powerpc (and possibly ia64) before it has been read from the device-tree, which leads to large slab consumption with CONFIG_SLUB and memoryless nodes. NUMA powerpc non-boot CPU's cpu_to_node/cpu_to_mem is only accurate after start_secondary(), similar to ia64, which is invoked via smp_init(). Commit 6ee0578b4daae ("workqueue: mark init_workqueues() as early_initcall()") made init_workqueues() be invoked via do_pre_smp_initcalls(), which is obviously before the secondary processors are online. Additionally, the following commits changed init_workqueues() to use cpu_to_node to determine the node to use for kthread_create_on_node: bce903809ab3f ("workqueue: add wq_numa_tbl_len and wq_numa_possible_cpumask[]") f3f90ad469342 ("workqueue: determine NUMA node of workers accourding to the allowed cpumask") Therefore, when init_workqueues() runs, it sees all CPUs as being on Node 0. On LPARs or KVM guests where Node 0 is memoryless, this leads to a high number of slab deactivations (http://www.spinics.net/lists/linux-mm/msg67489.html). Fix this by initializing the powerpc-specific CPU<->node/local memory node mapping as early as possible, which on powerpc is do_init_bootmem(). Currently that function initializes the mapping for the boot CPU, but we extend it to setup the mapping for all possible CPUs. Then, in smp_prepare_cpus(), we can correspondingly set the per-cpu values for all possible CPUs. That ensures that before the early_initcalls run (and really as early as possible), the per-cpu NUMA mapping is accurate. While testing memoryless nodes on PowerKVM guests with a fix to the workqueue logic to use cpu_to_mem() instead of cpu_to_node(), with a guest topology of: available: 2 nodes (0-1) node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 node 0 size: 0 MB node 0 free: 0 MB node 1 cpus: 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 node 1 size: 16336 MB node 1 free: 15329 MB node distances: node 0 1 0: 10 40 1: 40 10 the slab consumption decreases from Slab: 932416 kB SUnreclaim: 902336 kB to Slab: 395264 kB SUnreclaim: 359424 kB And we a corresponding increase in the slab efficiency from slab mem objs slabs used active active ------------------------------------------------------------ kmalloc-16384 337 MB 11.28% 100.00% task_struct 288 MB 9.93% 100.00% to slab mem objs slabs used active active ------------------------------------------------------------ kmalloc-16384 37 MB 100.00% 100.00% task_struct 31 MB 100.00% 100.00% Powerpc didn't support memoryless nodes until recently (64bb80d87f01 "powerpc/numa: Enable CONFIG_HAVE_MEMORYLESS_NODES" and 8c272261194d "powerpc/numa: Enable USE_PERCPU_NUMA_NODE_ID"). Those commits also helped improve memory consumption with these kind of environments. Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* sched: Fix compiler warningsGuenter Roeck2014-07-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 143e1e28cb (sched: Rework sched_domain topology definition) introduced a number of functions with a return value of 'const int'. gcc doesn't know what to do with that and, if the kernel is compiled with W=1, complains with the following warnings whenever sched.h is included. include/linux/sched.h:875:25: warning: type qualifiers ignored on function return type include/linux/sched.h:882:25: warning: type qualifiers ignored on function return type include/linux/sched.h:889:25: warning: type qualifiers ignored on function return type include/linux/sched.h:1002:21: warning: type qualifiers ignored on function return type Commits fb2aa855 (sched, ARM: Create a dedicated scheduler topology table) and 607b45e9a (sched, powerpc: Create a dedicated topology table) introduce the same warning in the arm and powerpc code. Drop 'const' from the function declarations to fix the problem. The fix for all three patches has to be applied together to avoid compilation failures for the affected architectures. Acked-by: Vincent Guittot <vincent.guittot@linaro.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1403658329-13196-1-git-send-email-linux@roeck-us.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2014-06-12
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more scheduler updates from Ingo Molnar: "Second round of scheduler changes: - try-to-wakeup and IPI reduction speedups, from Andy Lutomirski - continued power scheduling cleanups and refactorings, from Nicolas Pitre - misc fixes and enhancements" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/deadline: Delete extraneous extern for to_ratio() sched/idle: Optimize try-to-wake-up IPI sched/idle: Simplify wake_up_idle_cpu() sched/idle: Clear polling before descheduling the idle thread sched, trace: Add a tracepoint for IPI-less remote wakeups cpuidle: Set polling in poll_idle sched: Remove redundant assignment to "rt_rq" in update_curr_rt(...) sched: Rename capacity related flags sched: Final power vs. capacity cleanups sched: Remove remaining dubious usage of "power" sched: Let 'struct sched_group_power' care about CPU capacity sched/fair: Disambiguate existing/remaining "capacity" usage sched/fair: Change "has_capacity" to "has_free_capacity" sched/fair: Remove "power" from 'struct numa_stats' sched: Fix signedness bug in yield_to() sched/fair: Use time_after() in record_wakee() sched/balancing: Reduce the rate of needless idle load balancing sched/fair: Fix unlocked reads of some cfs_b->quota/period
| * sched: Rename capacity related flagsNicolas Pitre2014-06-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is better not to think about compute capacity as being equivalent to "CPU power". The upcoming "power aware" scheduler work may create confusion with the notion of energy consumption if "power" is used too liberally. Let's rename the following feature flags since they do relate to capacity: SD_SHARE_CPUPOWER -> SD_SHARE_CPUCAPACITY ARCH_POWER -> ARCH_CAPACITY NONTASK_POWER -> NONTASK_CAPACITY Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: linaro-kernel@lists.linaro.org Cc: Andy Fleming <afleming@freescale.com> Cc: Anton Blanchard <anton@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Grant Likely <grant.likely@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/n/tip-e93lpnxb87owfievqatey6b5@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'next' of ↵Linus Torvalds2014-06-10
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull powerpc updates from Ben Herrenschmidt: "Here is the bulk of the powerpc changes for this merge window. It got a bit delayed in part because I wasn't paying attention, and in part because I discovered I had a core PCI change without a PCI maintainer ack in it. Bjorn eventually agreed it was ok to merge it though we'll probably improve it later and I didn't want to rebase to add his ack. There is going to be a bit more next week, essentially fixes that I still want to sort through and test. The biggest item this time is the support to build the ppc64 LE kernel with our new v2 ABI. We previously supported v2 userspace but the kernel itself was a tougher nut to crack. This is now sorted mostly thanks to Anton and Rusty. We also have a fairly big series from Cedric that add support for 64-bit LE zImage boot wrapper. This was made harder by the fact that traditionally our zImage wrapper was always 32-bit, but our new LE toolchains don't really support 32-bit anymore (it's somewhat there but not really "supported") so we didn't want to rely on it. This meant more churn that just endian fixes. This brings some more LE bits as well, such as the ability to run in LE mode without a hypervisor (ie. under OPAL firmware) by doing the right OPAL call to reinitialize the CPU to take HV interrupts in the right mode and the usual pile of endian fixes. There's another series from Gavin adding EEH improvements (one day we *will* have a release with less than 20 EEH patches, I promise!). Another highlight is the support for the "Split core" functionality on P8 by Michael. This allows a P8 core to be split into "sub cores" of 4 threads which allows the subcores to run different guests under KVM (the HW still doesn't support a partition per thread). And then the usual misc bits and fixes ..." [ Further delayed by gmail deciding that BenH is a dirty spammer. Google knows. ] * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (155 commits) powerpc/powernv: Add missing include to LPC code selftests/powerpc: Test the THP bug we fixed in the previous commit powerpc/mm: Check paca psize is up to date for huge mappings powerpc/powernv: Pass buffer size to OPAL validate flash call powerpc/pseries: hcall functions are exported to modules, need _GLOBAL_TOC() powerpc: Exported functions __clear_user and copy_page use r2 so need _GLOBAL_TOC() powerpc/powernv: Set memory_block_size_bytes to 256MB powerpc: Allow ppc_md platform hook to override memory_block_size_bytes powerpc/powernv: Fix endian issues in memory error handling code powerpc/eeh: Skip eeh sysfs when eeh is disabled powerpc: 64bit sendfile is capped at 2GB powerpc/powernv: Provide debugfs access to the LPC bus via OPAL powerpc/serial: Use saner flags when creating legacy ports powerpc: Add cpu family documentation powerpc/xmon: Fix up xmon format strings powerpc/powernv: Add calls to support little endian host powerpc: Document sysfs DSCR interface powerpc: Fix regression of per-CPU DSCR setting powerpc: Split __SYSFS_SPRSETUP macro arch: powerpc/fadump: Cleaning up inconsistent NULL checks ...
| * powerpc: Check cpu_thread_in_subcore() in __cpu_up()Michael Ellerman2014-05-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To support split core we need to change the check in __cpu_up() that determines if a cpu is allowed to come online. Currently we refuse to online cpus which are not the primary thread within their core. On POWER8 with split core support this check needs to instead refuse to online cpus which are not the primary thread within their *sub* core. On POWER7 and other systems that do not support split core, threads_per_subcore == threads_per_core and so the check is equivalent. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * powerpc/kvm/book3s_hv: Rework the secondary inhibit codeMichael Ellerman2014-05-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As part of the support for split core on POWER8, we want to be able to block splitting of the core while KVM VMs are active. The logic to do that would be exactly the same as the code we currently have for inhibiting onlining of secondaries. Instead of adding an identical mechanism to block split core, rework the secondary inhibit code to be a "HV KVM is active" check. We can then use that in both the cpu hotplug code and the upcoming split core code. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michael Neuling <mikey@neuling.org> Acked-by: Alexander Graf <agraf@suse.de> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * powerpc/numa: Enable CONFIG_HAVE_MEMORYLESS_NODESNishanth Aravamudan2014-05-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based off fd1197f1 for ia64, enable CONFIG_HAVE_MEMORYLESS_NODES if NUMA. Initialize the local memory node in start_secondary. With this commit and the preceding to enable CONFIG_USER_PERCPU_NUMA_NODE_ID, which is a prerequisite, in a PowerKVM guest with the following topology: numactl --hardware available: 3 nodes (0-2) node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 node 0 size: 1998 MB node 0 free: 521 MB node 1 cpus: 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 node 1 size: 0 MB node 1 free: 0 MB node 2 cpus: node 2 size: 2039 MB node 2 free: 1739 MB node distances: node 0 1 2 0: 10 40 40 1: 40 10 40 2: 40 40 10 the unreclaimable slab is reduced by close to 130M: Before: Slab: 418176 kB SReclaimable: 26624 kB SUnreclaim: 391552 kB After: Slab: 298944 kB SReclaimable: 31744 kB SUnreclaim: 267200 kB Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * powerpc/numa: Enable USE_PERCPU_NUMA_NODE_IDNishanth Aravamudan2014-05-27
| | | | | | | | | | | | | | | | | | | | | | | | Based off 3bccd996 for ia64, convert powerpc to use the generic per-CPU topology tracking, specifically: initialize per cpu numa_node entry in start_secondary remove the powerpc cpu_to_node() define CONFIG_USE_PERCPU_NUMA_NODE_ID if NUMA Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | sched, powerpc: Create a dedicated topology tableVincent Guittot2014-05-07
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Create a dedicated topology table for handling asymetric feature of powerpc. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Andy Fleming <afleming@freescale.com> Cc: Anton Blanchard <anton@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Grant Likely <grant.likely@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Preeti U. Murthy <preeti@linux.vnet.ibm.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Cc: tony.luck@intel.com Cc: fenghua.yu@intel.com Cc: schwidefsky@de.ibm.com Cc: cmetcalf@tilera.com Cc: dietmar.eggemann@arm.com Cc: devicetree@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/1397209481-28542-4-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* powerpc: Implement tick broadcast IPI as a fixed IPI messageSrivatsa S. Bhat2014-03-04
| | | | | | | | | | | | | | | | | | | For scalability and performance reasons, we want the tick broadcast IPIs to be handled as efficiently as possible. Fixed IPI messages are one of the most efficient mechanisms available - they are faster than the smp_call_function mechanism because the IPI handlers are fixed and hence they don't involve costly operations such as adding IPI handlers to the target CPU's function queue, acquiring locks for synchronization etc. Luckily we have an unused IPI message slot, so use that to implement tick broadcast IPIs efficiently. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> [Functions renamed to tick_broadcast* and Changelog modified by Preeti U. Murthy<preeti@linux.vnet.ibm.com>] Signed-off-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com> Acked-by: Geoff Levand <geoff@infradead.org> [For the PS3 part] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Free up the slot of PPC_MSG_CALL_FUNC_SINGLE IPI messageSrivatsa S. Bhat2014-03-04
| | | | | | | | | | | | | | | | The IPI handlers for both PPC_MSG_CALL_FUNC and PPC_MSG_CALL_FUNC_SINGLE map to a common implementation - generic_smp_call_function_single_interrupt(). So, we can consolidate them and save one of the IPI message slots, (which are precious on powerpc, since only 4 of those slots are available). So, implement the functionality of PPC_MSG_CALL_FUNC_SINGLE using PPC_MSG_CALL_FUNC itself and release its IPI message slot, so that it can be used for something else in the future, if desired. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com> Acked-by: Geoff Levand <geoff@infradead.org> [For the PS3 part] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* Merge branch 'merge' into nextBenjamin Herrenschmidt2013-12-29
|\ | | | | | | | | | | | | Merge a pile of fixes that went into the "merge" branch (3.13-rc's) such as Anton Little Endian fixes. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * powerpc: Fix topology core_id endian issue on LE buildsAnton Blanchard2013-12-12
| | | | | | | | | | | | | | | | | | | | cpu_to_core_id() is missing a byteswap: cat /sys/devices/system/cpu/cpu63/topology/core_id 201326592 Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | powerpc: kernel: remove useless code which related with 'max_cpus'Chen Gang2013-12-01
|/ | | | | | | | | | | | | | | | | Since not need 'max_cpus' after the related commit, the related code are useless too, need be removed. The related commit: c1aa687 powerpc: Clean up obsolete code relating to decrementer and timebase The related warning: arch/powerpc/kernel/smp.c:323:43: warning: parameter ‘max_cpus’ set but not used [-Wunused-but-set-parameter] Signed-off-by: Chen Gang <gang.chen@asianux.com> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Make cpu_to_chip_id() available when SMP=nMichael Ellerman2013-11-20
| | | | | | | | | | | | | | | | | Up until now we have only used cpu_to_chip_id() in the topology code, which is only used on SMP builds. However my recent commit a4da0d5 "Implement arch_get_random_long/int() for powernv" added a usage when SMP=n, breaking the build. Move cpu_to_chip_id() into prom.c so it is available for SMP=n builds. We would move the extern to prom.h, but that breaks the include in topology.h. Instead we leave it in smp.h, but move it out of the CONFIG_SMP #ifdef. We also need to include asm/smp.h in rng.c, because the linux version skips asm/smp.h on UP. What a mess. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* hotplug, powerpc, x86: Remove cpu_hotplug_driver_lock()Toshi Kani2013-09-30
| | | | | | | | | | | | | | | | | | | | | | cpu_hotplug_driver_lock() serializes CPU online/offline operations when ARCH_CPU_PROBE_RELEASE is set. This lock interface is no longer necessary with the following reason: - lock_device_hotplug() now protects CPU online/offline operations, including the probe & release interfaces enabled by ARCH_CPU_PROBE_RELEASE. The use of cpu_hotplug_driver_lock() is redundant. - cpu_hotplug_driver_lock() is only valid when ARCH_CPU_PROBE_RELEASE is defined, which is misleading and is only enabled on powerpc. This patch removes the cpu_hotplug_driver_lock() interface. As a result, ARCH_CPU_PROBE_RELEASE only enables / disables the cpu probe & release interface as intended. There is no functional change in this patch. Signed-off-by: Toshi Kani <toshi.kani@hp.com> Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* powerpc: Export cpu_to_chip_id() to fix build errorGuenter Roeck2013-09-10
| | | | | | | | | | | | | | | | powerpc allmodconfig build fails with: ERROR: ".cpu_to_chip_id" [drivers/block/mtip32xx/mtip32xx.ko] undefined! The problem was introduced with commit 15863ff3b (powerpc: Make chip-id information available to userspace). Export the missing symbol. Cc: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Cc: Shivaprasad G Bhat <sbhat@linux.vnet.ibm.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Little endian SMP IPI demuxAnton Blanchard2013-08-14
| | | | | | | Add little endian support for demuxing SMP IPIs Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Make chip-id information available to userspaceVasant Hegde2013-08-14
| | | | | | | | | | | | | So far "/sys/devices/system/cpu/cpuX/topology/physical_package_id" was always default (-1) on ppc64 architecture. Now, some systems have an ibm,chip-id property in the cpu nodes in the device tree. On these systems, we now use this information to display physical_package_id. Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Shivaprasad G Bhat <sbhat@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Use ibm, chip-id property to compute cpu_core_mask if availablePaul Mackerras2013-08-14
| | | | | | | | | | | Some systems have an ibm,chip-id property in the cpu nodes in the device tree. On these systems, we now use that to compute the cpu_core_mask (i.e. the set of core siblings) rather than looking at cache properties. Signed-off-by: Paul Mackerras <paulus@samba.org> Tested-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Pull out cpu_core_mask updates into a separate functionPaul Mackerras2013-08-14
| | | | | | | | | This factors out the details of updating cpu_core_mask into a separate function, to make it easier to change how the mask is calculated later. This makes no functional change. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Add smp_generic_cpu_bootableAndy Fleming2013-08-14
| | | | | | | | | | Cell and PSeries both implemented their own versions of a cpu_bootable smp_op which do the same thing (well, the PSeries one has support for more than 2 threads). Copy the PSeries one to generic code, and rename it smp_generic_cpu_bootable. Signed-off-by: Andy Fleming <afleming@freescale.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Fix a number of sparse warningsAnton Blanchard2013-08-13
| | | | | | | Address some of the trivial sparse warnings in arch/powerpc. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Set cpu sibling mask before online cpuLi Zhong2013-06-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It seems following race is possible: cpu0 cpux smp_init->cpu_up->_cpu_up __cpu_up kick_cpu(1) ------------------------------------------------------------------------- waiting online ... ... notify CPU_STARTING set cpux active set cpux online ------------------------------------------------------------------------- finish waiting online ... sched_init_smp init_sched_domains(cpu_active_mask) build_sched_domains set cpux sibling info ------------------------------------------------------------------------- Execution of cpu0 and cpux could be concurrent between two separator lines. So if the cpux sibling information was set too late (normally impossible, but could be triggered by adding some delay in start_secondary, after setting cpu online), build_sched_domains() running on cpu0 might see cpux active, with an empty sibling mask, then cause some bad address accessing like following: [ 0.099855] Unable to handle kernel paging request for data at address 0xc00000038518078f [ 0.099868] Faulting instruction address: 0xc0000000000b7a64 [ 0.099883] Oops: Kernel access of bad area, sig: 11 [#1] [ 0.099895] PREEMPT SMP NR_CPUS=16 DEBUG_PAGEALLOC NUMA pSeries [ 0.099922] Modules linked in: [ 0.099940] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.10.0-rc1-00120-gb973425-dirty #16 [ 0.099956] task: c0000001fed80000 ti: c0000001fed7c000 task.ti: c0000001fed7c000 [ 0.099971] NIP: c0000000000b7a64 LR: c0000000000b7a40 CTR: c0000000000b4934 [ 0.099985] REGS: c0000001fed7f760 TRAP: 0300 Not tainted (3.10.0-rc1-00120-gb973425-dirty) [ 0.099997] MSR: 8000000000009032 <SF,EE,ME,IR,DR,RI> CR: 24272828 XER: 20000003 [ 0.100045] SOFTE: 1 [ 0.100053] CFAR: c000000000445ee8 [ 0.100064] DAR: c00000038518078f, DSISR: 40000000 [ 0.100073] GPR00: 0000000000000080 c0000001fed7f9e0 c000000000c84d48 0000000000000010 GPR04: 0000000000000010 0000000000000000 c0000001fc55e090 0000000000000000 GPR08: ffffffffffffffff c000000000b80b30 c000000000c962d8 00000003845ffc5f GPR12: 0000000000000000 c00000000f33d000 c00000000000b9e4 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000001 0000000000000000 GPR20: c000000000ccf750 0000000000000000 c000000000c94d48 c0000001fc504000 GPR24: c0000001fc504000 c0000001fecef848 c000000000c94d48 c000000000ccf000 GPR28: c0000001fc522090 0000000000000010 c0000001fecef848 c0000001fed7fae0 [ 0.100293] NIP [c0000000000b7a64] .get_group+0x84/0xc4 [ 0.100307] LR [c0000000000b7a40] .get_group+0x60/0xc4 [ 0.100318] Call Trace: [ 0.100332] [c0000001fed7f9e0] [c0000000000dbce4] .lock_is_held+0xa8/0xd0 (unreliable) [ 0.100354] [c0000001fed7fa70] [c0000000000bf62c] .build_sched_domains+0x728/0xd14 [ 0.100375] [c0000001fed7fbe0] [c000000000af67bc] .sched_init_smp+0x4fc/0x654 [ 0.100394] [c0000001fed7fce0] [c000000000adce24] .kernel_init_freeable+0x17c/0x30c [ 0.100413] [c0000001fed7fdb0] [c00000000000ba08] .kernel_init+0x24/0x12c [ 0.100431] [c0000001fed7fe30] [c000000000009f74] .ret_from_kernel_thread+0x5c/0x68 [ 0.100445] Instruction dump: [ 0.100456] 38800010 38a00000 4838e3f5 60000000 7c6307b4 2fbf0000 419e0040 3d220001 [ 0.100496] 78601f24 39491590 e93e0008 7d6a002a <7d69582a> f97f0000 7d4a002a e93e0010 [ 0.100559] ---[ end trace 31fd0ba7d8756001 ]--- This patch tries to move the sibling maps updating before notify_cpu_starting() and cpu online, and a write barrier there to make sure sibling maps are updated before active and online mask. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Delete __cpuinit usage from all usersPaul Gortmaker2013-06-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the powerpc uses of the __cpuinit macros. There are no __CPUINIT users in assembly files in powerpc. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Josh Boyer <jwboyer@gmail.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Use generic idle loopThomas Gleixner2013-04-08
| | | | | | | | | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Link: http://lkml.kernel.org/r/20130321215235.026838003@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* powerpc: fix ics_rtas_init and start_secondary section mismatchDaniel Borkmann2013-02-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | It seems, we're fine with just annotating the two functions. Thus, this fixes the following build warnings on ppc64: WARNING: arch/powerpc/sysdev/xics/built-in.o(.text+0x1664): The function .ics_rtas_init() references the function __init .xics_register_ics(). This is often because .ics_rtas_init lacks a __init annotation or the annotation of .xics_register_ics is wrong. WARNING: arch/powerpc/sysdev/built-in.o(.text+0x6044): The function .ics_rtas_init() references the function __init .xics_register_ics(). This is often because .ics_rtas_init lacks a __init annotation or the annotation of .xics_register_ics is wrong. WARNING: arch/powerpc/kernel/built-in.o(.text+0x2db30): The function .start_secondary() references the function __cpuinit .vdso_getcpu_init(). This is often because .start_secondary lacks a __cpuinit annotation or the annotation of .vdso_getcpu_init is wrong. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* POWERPC: drivers: remove __dev* attributes.Greg Kroah-Hartman2013-01-03
| | | | | | | | | | | | | | | | CONFIG_HOTPLUG is going away as an option. As a result, the __dev* markings need to be removed. This change removes the use of __devinit, __devexit_p, __devinitdata, __devinitconst, and __devexit from these drivers. Based on patches originally written by Bill Pemberton, but redone by me in order to handle some of the coding style issues better, by hand. Cc: Bill Pemberton <wfp5p@virginia.edu> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge commit 'origin/queue' into for-queueAlexander Graf2012-10-31
|\ | | | | | | | | | | Conflicts: arch/powerpc/include/asm/Kbuild arch/powerpc/include/uapi/asm/Kbuild
| * powerpc/smp: Do not disable IPI interrupts during suspendZhao Chenhui2012-09-19
| | | | | | | | | | | | | | | | | | | | | | During suspend, all interrupts including IPI will be disabled. In this case, the suspend process will hang in SMP. To prevent this, pass the flag IRQF_NO_SUSPEND when requesting IPI irq. Signed-off-by: Zhao Chenhui <chenhui.zhao@freescale.com> Signed-off-by: Li Yang <leoli@freescale.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
| * powerpc/smp: add generic_set_cpu_up() to set cpu_state as CPU_UP_PREPAREZhao Chenhui2012-09-12
| | | | | | | | | | | | | | | | | | | | In the case of cpu hotplug, the cpu_state should be set to CPU_UP_PREPARE when kicking cpu. Otherwise, the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(), which makes the delay in generic_cpu_die() not happen. Signed-off-by: Zhao Chenhui <chenhui.zhao@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
* | KVM: PPC: Book3S HV: Allow KVM guests to stop secondary threads coming onlinePaul Mackerras2012-10-30
|/ | | | | | | | | | | | | | | | | | | | | | When a Book3S HV KVM guest is running, we need the host to be in single-thread mode, that is, all of the cores (or at least all of the cores where the KVM guest could run) to be running only one active hardware thread. This is because of the hardware restriction in POWER processors that all of the hardware threads in the core must be in the same logical partition. Complying with this restriction is much easier if, from the host kernel's point of view, only one hardware thread is active. This adds two hooks in the SMP hotplug code to allow the KVM code to make sure that secondary threads (i.e. hardware threads other than thread 0) cannot come online while any KVM guest exists. The KVM code still has to check that any core where it runs a guest has the secondary threads offline, but having done that check it can now be sure that they will not come online while the guest is running. Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Alexander Graf <agraf@suse.de>
* powerpc: Make sure IPI handlers see data written by IPI sendersPaul Mackerras2012-09-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have been observing hangs, both of KVM guest vcpu tasks and more generally, where a process that is woken doesn't properly wake up and continue to run, but instead sticks in TASK_WAKING state. This happens because the update of rq->wake_list in ttwu_queue_remote() is not ordered with the update of ipi_message in smp_muxed_ipi_message_pass(), and the reading of rq->wake_list in scheduler_ipi() is not ordered with the reading of ipi_message in smp_ipi_demux(). Thus it is possible for the IPI receiver not to see the updated rq->wake_list and therefore conclude that there is nothing for it to do. In order to make sure that anything done before smp_send_reschedule() is ordered before anything done in the resulting call to scheduler_ipi(), this adds barriers in smp_muxed_message_pass() and smp_ipi_demux(). The barrier in smp_muxed_message_pass() is a full barrier to ensure that there is a full ordering between the smp_send_reschedule() caller and scheduler_ipi(). In smp_ipi_demux(), we use xchg() rather than xchg_local() because xchg() includes release and acquire barriers. Using xchg() rather than xchg_local() makes sense given that ipi_message is not just accessed locally. This moves the barrier between setting the message and calling the cause_ipi() function into the individual cause_ipi implementations. Most of them -- those that used outb, out_8 or similar -- already had a full barrier because out_8 etc. include a sync before the MMIO store. This adds an explicit barrier in the two remaining cases. These changes made no measurable difference to the speed of IPIs as measured using a simple ping-pong latency test across two CPUs on different cores of a POWER7 machine. The analysis of the reason why processes were not waking up properly is due to Milton Miller. Cc: stable@vger.kernel.org # v3.0+ Reported-by: Milton Miller <miltonm@bga.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Add VDSO version of getcpuAnton Blanchard2012-07-11
| | | | | | | | | | | | | | | | | | | We have a request for a fast method of getting CPU and NUMA node IDs from userspace. This patch implements a getcpu VDSO function, similar to x86. Ben suggested we use SPRG3 which is userspace readable. SPRG3 can be modified by a KVM guest, so we save the SPRG3 value in the paca and restore it when transitioning from the guest to the host. I have a glibc patch that implements sched_getcpu on top of this. Testing on a POWER7: baseline: 538 cycles vdso: 30 cycles Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/smp: remove call to ipi_call_lock()/ipi_call_unlock()Yong Zhang2012-07-03
| | | | | | | | | | | | | | | | 1) call_function.lock used in smp_call_function_many() is just to protect call_function.queue and &data->refs, cpu_online_mask is outside of the lock. And it's not necessary to protect cpu_online_mask, because data->cpumask is pre-calculate and even if a cpu is brougt up when calling arch_send_call_function_ipi_mask(), it's harmless because validation test in generic_smp_call_function_interrupt() will take care of it. 2) For cpu down issue, stop_machine() will guarantee that no concurrent smp_call_fuction() is processing. Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Use generic idle thread allocationThomas Gleixner2012-04-26
| | | | | | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Link: http://lkml.kernel.org/r/20120420124557.311212868@linutronix.de
* smp: Add task_struct argument to __cpu_up()Thomas Gleixner2012-04-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Preparatory patch to make the idle thread allocation for secondary cpus generic. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: David S. Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Richard Weinberger <richard@nod.at> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/20120420124556.964170564@linutronix.de
* Disintegrate asm/system.h for PowerPCDavid Howells2012-03-28
| | | | | | | | Disintegrate asm/system.h for PowerPC. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> cc: linuxppc-dev@lists.ozlabs.org
* Merge branch 'driver-core-next' of ↵Linus Torvalds2012-01-07
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core * 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (73 commits) arm: fix up some samsung merge sysdev conversion problems firmware: Fix an oops on reading fw_priv->fw in sysfs loading file Drivers:hv: Fix a bug in vmbus_driver_unregister() driver core: remove __must_check from device_create_file debugfs: add missing #ifdef HAS_IOMEM arm: time.h: remove device.h #include driver-core: remove sysdev.h usage. clockevents: remove sysdev.h arm: convert sysdev_class to a regular subsystem arm: leds: convert sysdev_class to a regular subsystem kobject: remove kset_find_obj_hinted() m86k: gpio - convert sysdev_class to a regular subsystem mips: txx9_sram - convert sysdev_class to a regular subsystem mips: 7segled - convert sysdev_class to a regular subsystem sh: dma - convert sysdev_class to a regular subsystem sh: intc - convert sysdev_class to a regular subsystem power: suspend - convert sysdev_class to a regular subsystem power: qe_ic - convert sysdev_class to a regular subsystem power: cmm - convert sysdev_class to a regular subsystem s390: time - convert sysdev_class to a regular subsystem ... Fix up conflicts with 'struct sysdev' removal from various platform drivers that got changed: - arch/arm/mach-exynos/cpu.c - arch/arm/mach-exynos/irq-eint.c - arch/arm/mach-s3c64xx/common.c - arch/arm/mach-s3c64xx/cpu.c - arch/arm/mach-s5p64x0/cpu.c - arch/arm/mach-s5pv210/common.c - arch/arm/plat-samsung/include/plat/cpu.h - arch/powerpc/kernel/sysfs.c and fix up cpu_is_hotpluggable() as per Greg in include/linux/cpu.h
| * Merge branch 'driver-core-next' into Linux 3.2Greg Kroah-Hartman2012-01-06
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This resolves the conflict in the arch/arm/mach-s3c64xx/s3c6400.c file, and it fixes the build error in the arch/x86/kernel/microcode_core.c file, that the merge did not catch. The microcode_core.c patch was provided by Stephen Rothwell <sfr@canb.auug.org.au> who was invaluable in the merge issues involved with the large sysdev removal process in the driver-core tree. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| | * cpu: convert 'cpu' and 'machinecheck' sysdev_class to a regular subsystemKay Sievers2011-12-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This moves the 'cpu sysdev_class' over to a regular 'cpu' subsystem and converts the devices to regular devices. The sysdev drivers are implemented as subsystem interfaces now. After all sysdev classes are ported to regular driver core entities, the sysdev implementation will be entirely removed from the kernel. Userspace relies on events and generic sysfs subsystem infrastructure from sysdev devices, which are made available with this conversion. Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <bp@amd64.org> Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk> Cc: Len Brown <lenb@kernel.org> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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