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* Merge branch 'smp-hotplug-for-linus' of ↵Linus Torvalds2016-12-124-124/+86
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull smp hotplug updates from Thomas Gleixner: "This is the final round of converting the notifier mess to the state machine. The removal of the notifiers and the related infrastructure will happen around rc1, as there are conversions outstanding in other trees. The whole exercise removed about 2000 lines of code in total and in course of the conversion several dozen bugs got fixed. The new mechanism allows to test almost every hotplug step standalone, so usage sites can exercise all transitions extensively. There is more room for improvement, like integrating all the pointlessly different architecture mechanisms of synchronizing, setting cpus online etc into the core code" * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits) tracing/rb: Init the CPU mask on allocation soc/fsl/qbman: Convert to hotplug state machine soc/fsl/qbman: Convert to hotplug state machine zram: Convert to hotplug state machine KVM/PPC/Book3S HV: Convert to hotplug state machine arm64/cpuinfo: Convert to hotplug state machine arm64/cpuinfo: Make hotplug notifier symmetric mm/compaction: Convert to hotplug state machine iommu/vt-d: Convert to hotplug state machine mm/zswap: Convert pool to hotplug state machine mm/zswap: Convert dst-mem to hotplug state machine mm/zsmalloc: Convert to hotplug state machine mm/vmstat: Convert to hotplug state machine mm/vmstat: Avoid on each online CPU loops mm/vmstat: Drop get_online_cpus() from init_cpu_node_state/vmstat_cpu_dead() tracing/rb: Convert to hotplug state machine oprofile/nmi timer: Convert to hotplug state machine net/iucv: Use explicit clean up labels in iucv_init() x86/pci/amd-bus: Convert to hotplug state machine x86/oprofile/nmi: Convert to hotplug state machine ...
| * tracing/rb: Init the CPU mask on allocationSebastian Andrzej Siewior2016-12-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before commit b32614c03413 ("tracing/rb: Convert to hotplug state machine") the allocated cpumask was initialized to the mask of online or possible CPUs. After the CPU hotplug changes the buffer initialization moved to trace_rb_cpu_prepare() but the cpumask is allocated with alloc_cpumask() and therefor has random content. As a consequence the cpu buffers are not initialized and a later access dereferences a NULL pointer. Use zalloc_cpumask() instead so trace_rb_cpu_prepare() initializes the buffers properly. Fixes: b32614c03413 ("tracing/rb: Convert to hotplug state machine") Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: rostedt@goodmis.org Link: http://lkml.kernel.org/r/20161207133133.hzkcqfllxcdi3joz@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * tracing/rb: Convert to hotplug state machineSebastian Andrzej Siewior2016-12-022-91/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Install the callbacks via the state machine. The notifier in struct ring_buffer is replaced by the multi instance interface. Upon __ring_buffer_alloc() invocation, cpuhp_state_add_instance() will invoke the trace_rb_cpu_prepare() on each CPU. This callback may now fail. This means __ring_buffer_alloc() will fail and cleanup (like previously) and during a CPU up event this failure will not allow the CPU to come up. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20161126231350.10321-7-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * sched/nohz: Convert to hotplug state machineSebastian Andrzej Siewior2016-11-221-19/+14
| | | | | | | | | | | | | | | | | | | | Install the callbacks via the state machine. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: rt@linuxtronix.de Link: http://lkml.kernel.org/r/20161117183541.8588-14-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * kernel/printk: Block cpuhotplug callback when tasks are frozenThomas Gleixner2016-11-171-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recent conversion of the console hotplug notifier to the state machine missed the fact, that the notifier only operated on the non frozen transitions. As a consequence the console_lock/unlock() pair is also invoked during suspend, which results in a lockdep warning. Restore the previous state by making the lock/unlock conditional on !tasks_frozen. Fixes: 90b14889d2f9 ("kernel/printk: Convert to hotplug state machine") Reported-and-tested-by: Borislav Petkov <bp@alien8.de> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1611171729320.3645@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
| * kernel/printk: Convert to hotplug state machineSebastian Andrzej Siewior2016-11-091-16/+13
| | | | | | | | | | | | | | | | | | | | | | | | Install the callbacks via the state machine. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20161103145021.28528-3-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds2016-12-121-7/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "The main changes in this development cycle were: - a large number of call stack dumping/printing improvements: higher robustness, better cross-context dumping, improved output, etc. (Josh Poimboeuf) - vDSO getcpu() performance improvement for future Intel CPUs with the RDPID instruction (Andy Lutomirski) - add two new Intel AVX512 features and the CPUID support infrastructure for it: AVX512IFMA and AVX512VBMI. (Gayatri Kammela, He Chen) - more copy-user unification (Borislav Petkov) - entry code assembly macro simplifications (Alexander Kuleshov) - vDSO C/R support improvements (Dmitry Safonov) - misc fixes and cleanups (Borislav Petkov, Paul Bolle)" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) scripts/decode_stacktrace.sh: Fix address line detection on x86 x86/boot/64: Use defines for page size x86/dumpstack: Make stack name tags more comprehensible selftests/x86: Add test_vdso to test getcpu() x86/vdso: Use RDPID in preference to LSL when available x86/dumpstack: Handle NULL stack pointer in show_trace_log_lvl() x86/cpufeatures: Enable new AVX512 cpu features x86/cpuid: Provide get_scattered_cpuid_leaf() x86/cpuid: Cleanup cpuid_regs definitions x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants x86/unwind: Ensure stack grows down x86/vdso: Set vDSO pointer only after success x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE x86/unwind: Detect bad stack return address x86/dumpstack: Warn on stack recursion x86/unwind: Warn on bad frame pointer x86/decoder: Use stderr if insn sanity test fails x86/decoder: Use stdout if insn decoder test is successful mm/page_alloc: Remove kernel address exposure in free_reserved_area() x86/dumpstack: Remove raw stack dump ...
| * \ Merge branch 'x86/cpufeature' into x86/asm, to pick up dependencyIngo Molnar2016-11-174-22/+11
| |\ \ | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * \ \ Merge branch 'linus' into x86/asm, to pick up fixesIngo Molnar2016-11-019-53/+89
| |\ \ \ | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | x86/dumpstack: Remove raw stack dumpJosh Poimboeuf2016-10-251-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For mostly historical reasons, the x86 oops dump shows the raw stack values: ... [registers] Stack: ffff880079af7350 ffff880079905400 0000000000000000 ffffc900008f3ae0 ffffffffa0196610 0000000000000001 00010000ffffffff 0000000087654321 0000000000000002 0000000000000000 0000000000000000 0000000000000000 Call Trace: ... This seems to be an artifact from long ago, and probably isn't needed anymore. It generally just adds noise to the dump, and it can be actively harmful because it leaks kernel addresses. Linus says: "The stack dump actually goes back to forever, and it used to be useful back in 1992 or so. But it used to be useful mainly because stacks were simpler and we didn't have very good call traces anyway. I definitely remember having used them - I just do not remember having used them in the last ten+ years. Of course, it's still true that if you can trigger an oops, you've likely already lost the security game, but since the stack dump is so useless, let's aim to just remove it and make games like the above harder." This also removes the related 'kstack=' cmdline option and the 'kstack_depth_to_print' sysctl. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/e83bd50df52d8fe88e94d2566426ae40d813bf8f.1477405374.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | Merge branch 'smp-urgent-for-linus' of ↵Linus Torvalds2016-12-121-1/+1
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull hotplug API fix from Ingo Molnar: "Late breaking fix from the v4.9 cycle: fix a hotplug register/ unregister notifier API asymmetry bug that can cause kernel warnings (and worse) with certain Kconfig combinations" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: hotplug: Make register and unregister notifier API symmetric
| * | | | | hotplug: Make register and unregister notifier API symmetricMichal Hocko2016-12-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Yu Zhao has noticed that __unregister_cpu_notifier only unregisters its notifiers when HOTPLUG_CPU=y while the registration might succeed even when HOTPLUG_CPU=n if MODULE is enabled. This means that e.g. zswap might keep a stale notifier on the list on the manual clean up during the pool tear down and thus corrupt the list. Resulting in the following [ 144.964346] BUG: unable to handle kernel paging request at ffff880658a2be78 [ 144.971337] IP: [<ffffffffa290b00b>] raw_notifier_chain_register+0x1b/0x40 <snipped> [ 145.122628] Call Trace: [ 145.125086] [<ffffffffa28e5cf8>] __register_cpu_notifier+0x18/0x20 [ 145.131350] [<ffffffffa2a5dd73>] zswap_pool_create+0x273/0x400 [ 145.137268] [<ffffffffa2a5e0fc>] __zswap_param_set+0x1fc/0x300 [ 145.143188] [<ffffffffa2944c1d>] ? trace_hardirqs_on+0xd/0x10 [ 145.149018] [<ffffffffa2908798>] ? kernel_param_lock+0x28/0x30 [ 145.154940] [<ffffffffa2a3e8cf>] ? __might_fault+0x4f/0xa0 [ 145.160511] [<ffffffffa2a5e237>] zswap_compressor_param_set+0x17/0x20 [ 145.167035] [<ffffffffa2908d3c>] param_attr_store+0x5c/0xb0 [ 145.172694] [<ffffffffa290848d>] module_attr_store+0x1d/0x30 [ 145.178443] [<ffffffffa2b2b41f>] sysfs_kf_write+0x4f/0x70 [ 145.183925] [<ffffffffa2b2a5b9>] kernfs_fop_write+0x149/0x180 [ 145.189761] [<ffffffffa2a99248>] __vfs_write+0x18/0x40 [ 145.194982] [<ffffffffa2a9a412>] vfs_write+0xb2/0x1a0 [ 145.200122] [<ffffffffa2a9a732>] SyS_write+0x52/0xa0 [ 145.205177] [<ffffffffa2ff4d97>] entry_SYSCALL_64_fastpath+0x12/0x17 This can be even triggered manually by changing /sys/module/zswap/parameters/compressor multiple times. Fix this issue by making unregister APIs symmetric to the register so there are no surprises. Fixes: 47e627bc8c9a ("[PATCH] hotplug: Allow modules to use the cpu hotplug notifiers even if !CONFIG_HOTPLUG_CPU") Reported-and-tested-by: Yu Zhao <yuzhao@google.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: linux-mm@kvack.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Streetman <ddstreet@ieee.org> Link: http://lkml.kernel.org/r/20161207135438.4310-1-mhocko@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | | | Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2016-12-1210-330/+669
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main scheduler changes in this cycle were: - support Intel Turbo Boost Max Technology 3.0 (TBM3) by introducig a notion of 'better cores', which the scheduler will prefer to schedule single threaded workloads on. (Tim Chen, Srinivas Pandruvada) - enhance the handling of asymmetric capacity CPUs further (Morten Rasmussen) - improve/fix load handling when moving tasks between task groups (Vincent Guittot) - simplify and clean up the cputime code (Stanislaw Gruszka) - improve mass fork()ed task spread a.k.a. hackbench speedup (Vincent Guittot) - make struct kthread kmalloc()ed and related fixes (Oleg Nesterov) - add uaccess atomicity debugging (when using access_ok() in the wrong context), under CONFIG_DEBUG_ATOMIC_SLEEP=y (Peter Zijlstra) - implement various fixes, cleanups and other enhancements (Daniel Bristot de Oliveira, Martin Schwidefsky, Rafael J. Wysocki)" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits) sched/core: Use load_avg for selecting idlest group sched/core: Fix find_idlest_group() for fork kthread: Don't abuse kthread_create_on_cpu() in __kthread_create_worker() kthread: Don't use to_live_kthread() in kthread_[un]park() kthread: Don't use to_live_kthread() in kthread_stop() Revert "kthread: Pin the stack via try_get_task_stack()/put_task_stack() in to_live_kthread() function" kthread: Make struct kthread kmalloc'ed x86/uaccess, sched/preempt: Verify access_ok() context sched/x86: Make CONFIG_SCHED_MC_PRIO=y easier to enable sched/x86: Change CONFIG_SCHED_ITMT to CONFIG_SCHED_MC_PRIO x86/sched: Use #include <linux/mutex.h> instead of #include <asm/mutex.h> cpufreq/intel_pstate: Use CPPC to get max performance acpi/bus: Set _OSC for diverse core support acpi/bus: Enable HWP CPPC objects x86/sched: Add SD_ASYM_PACKING flags to x86 ITMT CPU x86/sysctl: Add sysctl for ITMT scheduling feature x86: Enable Intel Turbo Boost Max Technology 3.0 x86/topology: Define x86's arch_update_cpu_topology sched: Extend scheduler's asym packing sched/fair: Clean up the tunable parameter definitions ...
| * | | | | | sched/core: Use load_avg for selecting idlest groupVincent Guittot2016-12-111-11/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | find_idlest_group() only compares the runnable_load_avg when looking for the least loaded group. But on fork intensive use case like hackbench where tasks blocked quickly after the fork, this can lead to selecting the same CPU instead of other CPUs, which have similar runnable load but a lower load_avg. When the runnable_load_avg of 2 CPUs are close, we now take into account the amount of blocked load as a 2nd selection factor. There is now 3 zones for the runnable_load of the rq: - [0 .. (runnable_load - imbalance)]: Select the new rq which has significantly less runnable_load - [(runnable_load - imbalance) .. (runnable_load + imbalance)]: The runnable loads are close so we use load_avg to chose between the 2 rq - [(runnable_load + imbalance) .. ULONG_MAX]: Keep the current rq which has significantly less runnable_load The scale factor that is currently used for comparing runnable_load, doesn't work well with small value. As an example, the use of a scaling factor fails as soon as this_runnable_load == 0 because we always select local rq even if min_runnable_load is only 1, which doesn't really make sense because they are just the same. So instead of scaling factor, we use an absolute margin for runnable_load to detect CPUs with similar runnable_load and we keep using scaling factor for blocked load. For use case like hackbench, this enable the scheduler to select different CPUs during the fork sequence and to spread tasks across the system. Tests have been done on a Hikey board (ARM based octo cores) for several kernel. The result below gives min, max, avg and stdev values of 18 runs with each configuration. The patches depend on the "no missing update_rq_clock()" work. hackbench -P -g 1 ea86cb4b7621 7dc603c9028e v4.8 v4.8+patches min 0.049 0.050 0.051 0,048 avg 0.057 0.057(0%) 0.057(0%) 0,055(+5%) max 0.066 0.068 0.070 0,063 stdev +/-9% +/-9% +/-8% +/-9% More performance numbers here: https://lkml.kernel.org/r/20161203214707.GI20785@codeblueprint.co.uk Tested-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dietmar.eggemann@arm.com Cc: kernellwp@gmail.com Cc: umgwanakikbuti@gmail.com Cc: yuyang.du@intel.comc Link: http://lkml.kernel.org/r/1481216215-24651-3-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | sched/core: Fix find_idlest_group() for forkVincent Guittot2016-12-111-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During fork, the utilization of a task is init once the rq has been selected because the current utilization level of the rq is used to set the utilization of the fork task. As the task's utilization is still 0 at this step of the fork sequence, it doesn't make sense to look for some spare capacity that can fit the task's utilization. Furthermore, I can see perf regressions for the test: hackbench -P -g 1 because the least loaded policy is always bypassed and tasks are not spread during fork. With this patch and the fix below, we are back to same performances as for v4.8. The fix below is only a temporary one used for the test until a smarter solution is found because we can't simply remove the test which is useful for others benchmarks | @@ -5708,13 +5708,6 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t | | avg_cost = this_sd->avg_scan_cost; | | - /* | - * Due to large variance we need a large fuzz factor; hackbench in | - * particularly is sensitive here. | - */ | - if ((avg_idle / 512) < avg_cost) | - return -1; | - | time = local_clock(); | | for_each_cpu_wrap(cpu, sched_domain_span(sd), target, wrap) { Tested-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Acked-by: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dietmar.eggemann@arm.com Cc: kernellwp@gmail.com Cc: umgwanakikbuti@gmail.com Cc: yuyang.du@intel.comc Link: http://lkml.kernel.org/r/1481216215-24651-2-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | Merge branch 'linus' into sched/core, to pick up fixesIngo Molnar2016-12-118-64/+152
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | kthread: Don't abuse kthread_create_on_cpu() in __kthread_create_worker()Oleg Nesterov2016-12-081-15/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kthread_create_on_cpu() sets KTHREAD_IS_PER_CPU and kthread->cpu, this only makes sense if this kthread can be parked/unparked by cpuhp code. kthread workers never call kthread_parkme() so this has no effect. Change __kthread_create_worker() to simply call kthread_bind(task, cpu). The very fact that kthread_create_on_cpu() doesn't accept a generic fmt shows that it should not be used outside of smpboot.c. Now, the only reason we can not unexport this helper and move it into smpboot.c is that it sets kthread->cpu and struct kthread is not exported. And the only reason we can not kill kthread->cpu is that kthread_unpark() is used by drivers/gpu/drm/amd/scheduler/gpu_scheduler.c and thus we can not turn _unpark into kthread_unpark(struct smp_hotplug_thread *, cpu). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Tested-by: Petr Mladek <pmladek@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Chunming Zhou <David1.Zhou@amd.com> Cc: Roman Pen <roman.penyaev@profitbricks.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Tejun Heo <tj@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20161129175110.GA5342@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | | kthread: Don't use to_live_kthread() in kthread_[un]park()Oleg Nesterov2016-12-081-45/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that to_kthread() is always validm change kthread_park() and kthread_unpark() to use it and kill to_live_kthread(). The conversion of kthread_unpark() is trivial. If KTHREAD_IS_PARKED is set then the task has called complete(&self->parked) and there the function cannot race against a concurrent kthread_stop() and exit. kthread_park() is more tricky, because its semantics are not well defined. It returns -ENOSYS if the thread exited but this can never happen and as Roman pointed out kthread_park() can obviously block forever if it would race with the exiting kthread. The usage of kthread_park() in cpuhp code (cpu.c, smpboot.c, stop_machine.c) is fine. It can never see an exiting/exited kthread, smpboot_destroy_threads() clears *ht->store, smpboot_park_thread() checks it is not NULL under the same smpboot_threads_lock. cpuhp_threads and cpu_stop_threads never exit, so other callers are fine too. But it has two more users: - watchdog_park_threads(): The code is actually correct, get_online_cpus() ensures that kthread_park() can't race with itself (note that kthread_park() can't handle this race correctly), but it should not use kthread_park() directly. - drivers/gpu/drm/amd/scheduler/gpu_scheduler.c should not use kthread_park() either. kthread_park() must not be called after amd_sched_fini() which does kthread_stop(), otherwise even to_live_kthread() is not safe because task_struct can be already freed and sched->thread can point to nowhere. The usage of kthread_park/unpark should either be restricted to core code which is properly protected against the exit race or made more robust so it is safe to use it in drivers. To catch eventual exit issues, add a WARN_ON(PF_EXITING) for now. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chunming Zhou <David1.Zhou@amd.com> Cc: Roman Pen <roman.penyaev@profitbricks.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Tejun Heo <tj@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20161129175107.GA5339@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | | kthread: Don't use to_live_kthread() in kthread_stop()Oleg Nesterov2016-12-081-7/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kthread_stop() had to use to_live_kthread() simply because it was not possible to access kthread->exited after the exiting task clears task_struct->vfork_done. Now that to_kthread() is always valid, wake_up_process() + wait_for_completion() can be done ununconditionally. It's not an issue anymore if the task has already issued complete_vfork_done() or died. The exiting task can get the spurious wakeup after mm_release() but this is possible without this change too and is fine; do_task_dead() ensures that this can't make any harm. As a further enhancement this could be converted to task_work_add() later, so ->vfork_done can be avoided completely. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chunming Zhou <David1.Zhou@amd.com> Cc: Roman Pen <roman.penyaev@profitbricks.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Tejun Heo <tj@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20161129175103.GA5336@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | | Revert "kthread: Pin the stack via try_get_task_stack()/put_task_stack() in ↵Oleg Nesterov2016-12-081-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | to_live_kthread() function" This reverts commit 23196f2e5f5d810578a772785807dcdc2b9fdce9. Now that struct kthread is kmalloc'ed and not longer on the task stack there is no need anymore to pin the stack. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chunming Zhou <David1.Zhou@amd.com> Cc: Roman Pen <roman.penyaev@profitbricks.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Tejun Heo <tj@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20161129175100.GA5333@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | | kthread: Make struct kthread kmalloc'edOleg Nesterov2016-12-082-13/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 23196f2e5f5d "kthread: Pin the stack via try_get_task_stack() / put_task_stack() in to_live_kthread() function" is a workaround for the fragile design of struct kthread being allocated on the task stack. struct kthread in its current form should be removed, but this needs cleanups outside of kthread.c. As a first step move struct kthread away from the task stack by making it kmalloc'ed. This allows to access kthread.exited without the magic of trying to pin task stack and the try logic in to_live_kthread(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chunming Zhou <David1.Zhou@amd.com> Cc: Roman Pen <roman.penyaev@profitbricks.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Tejun Heo <tj@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20161129175057.GA5330@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | | sched: Extend scheduler's asym packingTim Chen2016-11-243-17/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We generalize the scheduler's asym packing to provide an ordering of the cpu beyond just the cpu number. This allows the use of the ASYM_PACKING scheduler machinery to move loads to preferred CPU in a sched domain. The preference is defined with the cpu priority given by arch_asym_cpu_priority(cpu). We also record the most preferred cpu in a sched group when we build the cpu's capacity for fast lookup of preferred cpu during load balancing. Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: linux-pm@vger.kernel.org Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Cc: linux-acpi@vger.kernel.org Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: bp@suse.de Link: http://lkml.kernel.org/r/0e73ae12737dfaafa46c07066cc7c5d3f1675e46.1479844244.git.tim.c.chen@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | | sched/fair: Clean up the tunable parameter definitionsIngo Molnar2016-11-231-22/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No change in functionality: - align the default values vertically to make them easier to scan - standardize the 'default:' lines - fix minor whitespace typos Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | sched/dl: Fix comment in pick_next_task_dl()T.Zhou2016-11-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix cut & paste oversight: s/pull_rt_task/pull_dl_task Signed-off-by: T.Zhou <t1zhou@163.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: juri.lelli@gmail.com Link: http://lkml.kernel.org/r/20161123004832.GA2983@geo Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | Merge branch 'linus' into sched/core, to pick up fixesIngo Molnar2016-11-234-34/+93
| |\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | sched/fair: Fix task group initializationVincent Guittot2016-11-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The moves of tasks are now propagated down to root and the utilization of cfs_rq reflects reality so it doesn't need to be estimated at init. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bsegall@google.com Cc: kernellwp@gmail.com Cc: pjt@google.com Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1478598827-32372-7-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | sched/fair: Propagate asynchrous detachVincent Guittot2016-11-161-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A task can be asynchronously detached from cfs_rq when migrating between CPUs. The load of the migrated task is then removed from source cfs_rq during its next update. We use this event to set propagation flag. During the load balance, we take advantage of the update of blocked load to propagate any pending changes. The propagation relies on patch: "sched: Fix hierarchical order in rq->leaf_cfs_rq_list" ... which orders children and parents, to ensure that it's done in one pass. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bsegall@google.com Cc: kernellwp@gmail.com Cc: pjt@google.com Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1478598827-32372-6-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | sched/fair: Propagate load during synchronous attach/detachVincent Guittot2016-11-162-1/+188
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a task moves from/to a cfs_rq, we set a flag which is then used to propagate the change at parent level (sched_entity and cfs_rq) during next update. If the cfs_rq is throttled, the flag will stay pending until the cfs_rq is unthrottled. For propagating the utilization, we copy the utilization of group cfs_rq to the sched_entity. For propagating the load, we have to take into account the load of the whole task group in order to evaluate the load of the sched_entity. Similarly to what was done before the rewrite of PELT, we add a correction factor in case the task group's load is greater than its share so it will contribute the same load of a task of equal weight. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bsegall@google.com Cc: kernellwp@gmail.com Cc: pjt@google.com Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1478598827-32372-5-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | sched/fair: Factorize PELT updateVincent Guittot2016-11-161-51/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Every time we modify load/utilization of sched_entity, we start to sync it with its cfs_rq. This update is done in different ways: - when attaching/detaching a sched_entity, we update cfs_rq and then we sync the entity with the cfs_rq. - when enqueueing/dequeuing the sched_entity, we update both sched_entity and cfs_rq metrics to now. Use update_load_avg() everytime we have to update and sync cfs_rq and sched_entity before changing the state of a sched_enity. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bsegall@google.com Cc: kernellwp@gmail.com Cc: pjt@google.com Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1478598827-32372-4-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | sched/fair: Fix hierarchical order in rq->leaf_cfs_rq_listVincent Guittot2016-11-163-7/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the insertion of cfs_rq in rq->leaf_cfs_rq_list to ensure that a child will always be called before its parent. The hierarchical order in shares update list has been introduced by commit: 67e86250f8ea ("sched: Introduce hierarchal order on shares update list") With the current implementation a child can be still put after its parent. Lets take the example of: root \ b /\ c d* | e* with root -> b -> c already enqueued but not d -> e so the leaf_cfs_rq_list looks like: head -> c -> b -> root -> tail The branch d -> e will be added the first time that they are enqueued, starting with e then d. When e is added, its parents is not already on the list so e is put at the tail : head -> c -> b -> root -> e -> tail Then, d is added at the head because its parent is already on the list: head -> d -> c -> b -> root -> e -> tail e is not placed at the right position and will be called the last whereas it should be called at the beginning. Because it follows the bottom-up enqueue sequence, we are sure that we will finished to add either a cfs_rq without parent or a cfs_rq with a parent that is already on the list. We can use this event to detect when we have finished to add a new branch. For the others, whose parents are not already added, we have to ensure that they will be added after their children that have just been inserted the steps before, and after any potential parents that are already in the list. The easiest way is to put the cfs_rq just after the last inserted one and to keep track of it untl the branch is fully added. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bsegall@google.com Cc: kernellwp@gmail.com Cc: pjt@google.com Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1478598827-32372-3-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | sched/fair: Factorize attach/detach entityVincent Guittot2016-11-161-22/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Factorize post_init_entity_util_avg() and part of attach_task_cfs_rq() in one function attach_entity_cfs_rq(). Create symmetric detach_entity_cfs_rq() function. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bsegall@google.com Cc: kernellwp@gmail.com Cc: pjt@google.com Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1478598827-32372-2-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | sched/fair: Fix incorrect comment for capacity_marginMorten Rasmussen2016-11-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The comment for capacity_margin introduced in: 3273163c6775 ("sched/fair: Let asymmetric CPU configurations balance at wake-up") ... got its usage the wrong way round - fix it. Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dietmar.eggemann@arm.com Cc: freedom.tan@mediatek.com Cc: keita.kobayashi.ym@renesas.com Cc: mgalbraith@suse.de Cc: sgurrappadi@nvidia.com Cc: vincent.guittot@linaro.org Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1476452472-24740-7-git-send-email-morten.rasmussen@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | sched/fair: Avoid pulling tasks from non-overloaded higher capacity groupsMorten Rasmussen2016-11-161-0/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For asymmetric CPU capacity systems it is counter-productive for throughput if low capacity CPUs are pulling tasks from non-overloaded CPUs with higher capacity. The assumption is that higher CPU capacity is preferred over running alone in a group with lower CPU capacity. This patch rejects higher CPU capacity groups with one or less task per CPU as potential busiest group which could otherwise lead to a series of failing load-balancing attempts leading to a force-migration. Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dietmar.eggemann@arm.com Cc: freedom.tan@mediatek.com Cc: keita.kobayashi.ym@renesas.com Cc: mgalbraith@suse.de Cc: sgurrappadi@nvidia.com Cc: vincent.guittot@linaro.org Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1476452472-24740-5-git-send-email-morten.rasmussen@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | sched/fair: Add per-CPU min capacity to sched_group_capacityMorten Rasmussen2016-11-163-7/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | struct sched_group_capacity currently represents the compute capacity sum of all CPUs in the sched_group. Unless it is divided by the group_weight to get the average capacity per CPU, it hides differences in CPU capacity for mixed capacity systems (e.g. high RT/IRQ utilization or ARM big.LITTLE). But even the average may not be sufficient if the group covers CPUs of different capacities. Instead, by extending struct sched_group_capacity to indicate min per-CPU capacity in the group a suitable group for a given task utilization can more easily be found such that CPUs with reduced capacity can be avoided for tasks with high utilization (not implemented by this patch). Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dietmar.eggemann@arm.com Cc: freedom.tan@mediatek.com Cc: keita.kobayashi.ym@renesas.com Cc: mgalbraith@suse.de Cc: sgurrappadi@nvidia.com Cc: vincent.guittot@linaro.org Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1476452472-24740-4-git-send-email-morten.rasmussen@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | sched/fair: Consider spare capacity in find_idlest_group()Morten Rasmussen2016-11-161-5/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In low-utilization scenarios comparing relative loads in find_idlest_group() doesn't always lead to the most optimum choice. Systems with groups containing different numbers of cpus and/or cpus of different compute capacity are significantly better off when considering spare capacity rather than relative load in those scenarios. In addition to existing load based search an alternative spare capacity based candidate sched_group is found and selected instead if sufficient spare capacity exists. If not, existing behaviour is preserved. Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dietmar.eggemann@arm.com Cc: freedom.tan@mediatek.com Cc: keita.kobayashi.ym@renesas.com Cc: mgalbraith@suse.de Cc: sgurrappadi@nvidia.com Cc: vincent.guittot@linaro.org Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1476452472-24740-3-git-send-email-morten.rasmussen@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | sched/fair: Compute task/cpu utilization at wake-up correctlyMorten Rasmussen2016-11-161-4/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At task wake-up load-tracking isn't updated until the task is enqueued. The task's own view of its utilization contribution may therefore not be aligned with its contribution to the cfs_rq load-tracking which may have been updated in the meantime. Basically, the task's own utilization hasn't yet accounted for the sleep decay, while the cfs_rq may have (partially). Estimating the cfs_rq utilization in case the task is migrated at wake-up as task_rq(p)->cfs.avg.util_avg - p->se.avg.util_avg is therefore incorrect as the two load-tracking signals aren't time synchronized (different last update). To solve this problem, this patch synchronizes the task utilization with its previous rq before the task utilization is used in the wake-up path. Currently the update/synchronization is done _after_ the task has been placed by select_task_rq_fair(). The synchronization is done without having to take the rq lock using the existing mechanism used in remove_entity_load_avg(). Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dietmar.eggemann@arm.com Cc: freedom.tan@mediatek.com Cc: keita.kobayashi.ym@renesas.com Cc: mgalbraith@suse.de Cc: sgurrappadi@nvidia.com Cc: vincent.guittot@linaro.org Cc: yuyang.du@intel.com Link: http://lkml.kernel.org/r/1476452472-24740-2-git-send-email-morten.rasmussen@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | sched/cpuacct: Avoid %lld seq_printf warningMartin Schwidefsky2016-11-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For s390 kernel builds I keep getting this warning: kernel/sched/cpuacct.c: In function 'cpuacct_stats_show': kernel/sched/cpuacct.c:298:25: warning: format '%lld' expects argument of type 'long long int', but argument 4 has type 'clock_t {aka long int}' [-Wformat=] seq_printf(sf, "%s %lld\n", Silence the warning by adding an explicit cast. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161111142749.6545-1-schwidefsky@de.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | Merge branch 'linus' into sched/core, to pick up fixesIngo Molnar2016-11-167-30/+39
| |\ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | sched/cputime: Simplify task_cputime()Stanislaw Gruszka2016-11-152-44/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now since fetch_task_cputime() has no other users than task_cputime(), its code could be used directly in task_cputime(). Moreover since only 2 task_cputime() calls of 17 use a NULL argument, we can add dummy variables to those calls and remove NULL checks from task_cputimes(). Also remove NULL checks from task_cputimes_scaled(). Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1479175612-14718-5-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | sched/cputime, powerpc, s390: Make scaled cputime arch specificStanislaw Gruszka2016-11-152-46/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Only s390 and powerpc have hardware facilities allowing to measure cputimes scaled by frequency. On all other architectures utimescaled/stimescaled are equal to utime/stime (however they are accounted separately). Remove {u,s}timescaled accounting on all architectures except powerpc and s390, where those values are explicitly accounted in the proper places. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161031162143.GB12646@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | sched/cputime, powerpc: Remove cputime_to_scaled()Stanislaw Gruszka2016-11-151-14/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently cputime_to_scaled() just return it's argument on all implementations, we don't need to call this function. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1479175612-14718-3-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | sched/deadline: Fix typo in a commentDaniel Bristot de Oliveira2016-11-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the comment: /* * The task might have changed its scheduling policy to something * different than SCHED_DEADLINE (through switched_fromd_dl()). */ s/fromd/from/ Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@unitn.it> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/5408b3b3f9ee197a7b7f10fb834341100a4f2c88.1478599881.git.bristot@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | Merge branch 'linus' into sched/core, to pick up fixesIngo Molnar2016-11-1110-62/+96
| |\ \ \ \ \ \ \ \ \ | | | |_|_|_|_|_|_|/ | | |/| | | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | sched/core: Explain sleep/wakeup in a better wayPeter Zijlstra2016-10-251-8/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There were a few questions wrt. how sleep-wakeup works. Try and explain it more. Requested-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | sched/fair: Kill the unused 'sched_shares_window_ns' tunableMatt Fleming2016-10-202-14/+0
| | |_|_|_|_|/ / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The last user of this tunable was removed in 2012 in commit: 82958366cfea ("sched: Replace update_shares weight distribution with per-entity computation") Delete it since its very existence confuses people. Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161019141059.26408-1-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | | | Merge branch 'locking-core-for-linus' of ↵Linus Torvalds2016-12-1215-335/+400
|\ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "The tree got pretty big in this development cycle, but the net effect is pretty good: 115 files changed, 673 insertions(+), 1522 deletions(-) The main changes were: - Rework and generalize the mutex code to remove per arch mutex primitives. (Peter Zijlstra) - Add vCPU preemption support: add an interface to query the preemption status of vCPUs and use it in locking primitives - this optimizes paravirt performance. (Pan Xinhui, Juergen Gross, Christian Borntraeger) - Introduce cpu_relax_yield() and remov cpu_relax_lowlatency() to clean up and improve the s390 lock yielding machinery and its core kernel impact. (Christian Borntraeger) - Micro-optimize mutexes some more. (Waiman Long) - Reluctantly add the to-be-deprecated mutex_trylock_recursive() interface on a temporary basis, to give the DRM code more time to get rid of its locking hacks. Any other users will be NAK-ed on sight. (We turned off the deprecation warning for the time being to not pollute the build log.) (Peter Zijlstra) - Improve the rtmutex code a bit, in light of recent long lived bugs/races. (Thomas Gleixner) - Misc fixes, cleanups" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/paravirt: Fix bool return type for PVOP_CALL() x86/paravirt: Fix native_patch() locking/ww_mutex: Use relaxed atomics locking/rtmutex: Explain locking rules for rt_mutex_proxy_unlock()/init_proxy_locked() locking/rtmutex: Get rid of RT_MUTEX_OWNER_MASKALL x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted() locking/mutex: Break out of expensive busy-loop on {mutex,rwsem}_spin_on_owner() when owner vCPU is preempted locking/osq: Break out of spin-wait busy waiting loop for a preempted vCPU in osq_lock() Documentation/virtual/kvm: Support the vCPU preemption check x86/xen: Support the vCPU preemption check x86/kvm: Support the vCPU preemption check x86/kvm: Support the vCPU preemption check kvm: Introduce kvm_write_guest_offset_cached() locking/core, x86/paravirt: Implement vcpu_is_preempted(cpu) for KVM and Xen guests locking/spinlocks, s390: Implement vcpu_is_preempted(cpu) locking/core, powerpc: Implement vcpu_is_preempted(cpu) sched/core: Introduce the vcpu_is_preempted(cpu) interface sched/wake_q: Rename WAKE_Q to DEFINE_WAKE_Q locking/core: Provide common cpu_relax_yield() definition locking/mutex: Don't mark mutex_trylock_recursive() as deprecated, temporarily ...
| * \ \ \ \ \ \ \ \ Merge branch 'linus' into locking/core, to pick up fixesIngo Molnar2016-12-116-70/+80
| |\ \ \ \ \ \ \ \ \ | | | |_|_|_|/ / / / | | |/| | | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | locking/rtmutex: Explain locking rules for ↵Thomas Gleixner2016-12-021-4/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rt_mutex_proxy_unlock()/init_proxy_locked() While debugging the unlock vs. dequeue race which resulted in state corruption of futexes the lockless nature of rt_mutex_proxy_unlock() caused some confusion. Add commentry to explain why it is safe to do this lockless. Add matching comments to rt_mutex_init_proxy_locked() for completeness sake. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David Daney <ddaney@caviumnetworks.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/20161130210030.591941927@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | locking/rtmutex: Get rid of RT_MUTEX_OWNER_MASKALLThomas Gleixner2016-12-021-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a left over from the original rtmutex implementation which used both bit0 and bit1 in the owner pointer. Commit: 8161239a8bcc ("rtmutex: Simplify PI algorithm and make highest prio task get lock") ... removed the usage of bit1, but kept the extra mask around. This is confusing at best. Remove it and just use RT_MUTEX_HAS_WAITERS for the masking. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David Daney <ddaney@caviumnetworks.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/20161130210030.509567906@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | | | | | Merge branch 'locking/urgent' into locking/core, to pick up dependent fixesIngo Molnar2016-12-025-12/+111
| |\ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
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