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* Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2017-06-182-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Thomas Gleixner: "Two small fixes for the schedulre core: - Use the proper switch_mm() variant in idle_task_exit() because that code is not called with interrupts disabled. - Fix a confusing typo in a printk" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Idle_task_exit() shouldn't use switch_mm_irqs_off() sched/fair: Fix typo in printk message
| * sched/core: Idle_task_exit() shouldn't use switch_mm_irqs_off()Andy Lutomirski2017-06-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | idle_task_exit() can be called with IRQs on x86 on and therefore should use switch_mm(), not switch_mm_irqs_off(). This doesn't seem to cause any problems right now, but it will confuse my upcoming TLB flush changes. Nonetheless, I think it should be backported because it's trivial. There won't be any meaningful performance impact because idle_task_exit() is only used when offlining a CPU. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Fixes: f98db6013c55 ("sched/core: Add switch_mm_irqs_off() and use it in the scheduler") Link: http://lkml.kernel.org/r/ca3d1a9fa93a0b49f5a8ff729eda3640fb6abdf9.1497034141.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * sched/fair: Fix typo in printk messageMarcin Nowakowski2017-06-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | 'schedstats' kernel parameter should be set to enable/disable, so correct the printk hint saying that it should be set to 'enable' rather than 'enabled' to enable scheduler tracepoints. Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com> 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/1496995229-31245-1-git-send-email-marcin.nowakowski@imgtec.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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*-. \ Merge branches 'pm-cpufreq', 'pm-cpuidle' and 'pm-devfreq'Rafael J. Wysocki2017-06-159-323/+608
|\ \ \ | | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * pm-cpufreq: cpufreq: conservative: Allow down_threshold to take values from 1 to 10 Revert "cpufreq: schedutil: Reduce frequencies slower" * pm-cpuidle: cpuidle: dt: Add missing 'of_node_put()' * pm-devfreq: PM / devfreq: exynos-ppmu: Staticize event list PM / devfreq: exynos-ppmu: Handle return value of clk_prepare_enable PM / devfreq: exynos-nocp: Handle return value of clk_prepare_enable
| | *---. Merge branches 'intel_pstate', 'pm-cpufreq' and 'pm-cpufreq-sched'Rafael J. Wysocki2017-05-221-4/+3
| | |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * intel_pstate: cpufreq: intel_pstate: Document the current behavior and user interface * pm-cpufreq: cpufreq: dbx500: add a Kconfig symbol * pm-cpufreq-sched: cpufreq: schedutil: use now as reference when aggregating shared policy requests
| | | | | * cpufreq: schedutil: use now as reference when aggregating shared policy requestsJuri Lelli2017-05-051-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, sugov_next_freq_shared() uses last_freq_update_time as a reference to decide when to start considering CPU contributions as stale. However, since last_freq_update_time is set by the last CPU that issued a frequency transition, this might cause problems in certain cases. In practice, the detection of stale utilization values fails whenever the CPU with such values was the last to update the policy. For example (and please note again that the SCHED_CPUFREQ_RT flag is not the problem here, but only the detection of after how much time that flag has to be considered stale), suppose a policy with 2 CPUs: CPU0 | CPU1 | | RT task scheduled | SCHED_CPUFREQ_RT is set | CPU1->last_update = now | freq transition to max | last_freq_update_time = now | more than TICK_NSEC nsecs | a small CFS wakes up | CPU0->last_update = now1 | delta_ns(CPU0) < TICK_NSEC* | CPU0's util is considered | delta_ns(CPU1) = | last_freq_update_time - | CPU1->last_update = 0 | < TICK_NSEC | CPU1 is still considered | CPU1->SCHED_CPUFREQ_RT is set | we stay at max (until CPU1 | exits from idle) | * delta_ns is actually negative as now1 > last_freq_update_time While last_freq_update_time is a sensible reference for rate limiting, it doesn't seem to be useful for working around stale CPU states. Fix the problem by always considering now (time) as the reference for deciding when CPUs have stale contributions. Signed-off-by: Juri Lelli <juri.lelli@arm.com> Acked-by: Vincent Guittot <vincent.guittot@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| | * | | | sched/core: Call __schedule() from do_idle() without enabling preemptionSteven Rostedt (VMware)2017-05-153-1/+28
| | |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I finally got around to creating trampolines for dynamically allocated ftrace_ops with using synchronize_rcu_tasks(). For users of the ftrace function hook callbacks, like perf, that allocate the ftrace_ops descriptor via kmalloc() and friends, ftrace was not able to optimize the functions being traced to use a trampoline because they would also need to be allocated dynamically. The problem is that they cannot be freed when CONFIG_PREEMPT is set, as there's no way to tell if a task was preempted on the trampoline. That was before Paul McKenney implemented synchronize_rcu_tasks() that would make sure all tasks (except idle) have scheduled out or have entered user space. While testing this, I triggered this bug: BUG: unable to handle kernel paging request at ffffffffa0230077 ... RIP: 0010:0xffffffffa0230077 ... Call Trace: schedule+0x5/0xe0 schedule_preempt_disabled+0x18/0x30 do_idle+0x172/0x220 What happened was that the idle task was preempted on the trampoline. As synchronize_rcu_tasks() ignores the idle thread, there's nothing that lets ftrace know that the idle task was preempted on a trampoline. The idle task shouldn't need to ever enable preemption. The idle task is simply a loop that calls schedule or places the cpu into idle mode. In fact, having preemption enabled is inefficient, because it can happen when idle is just about to call schedule anyway, which would cause schedule to be called twice. Once for when the interrupt came in and was returning back to normal context, and then again in the normal path that the idle loop is running in, which would be pointless, as it had already scheduled. The only reason schedule_preempt_disable() enables preemption is to be able to call sched_submit_work(), which requires preemption enabled. As this is a nop when the task is in the RUNNING state, and idle is always in the running state, there's no reason that idle needs to enable preemption. But that means it cannot use schedule_preempt_disable() as other callers of that function require calling sched_submit_work(). Adding a new function local to kernel/sched/ that allows idle to call the scheduler without enabling preemption, fixes the synchronize_rcu_tasks() issue, as well as removes the pointless spurious schedule calls caused by interrupts happening in the brief window where preemption is enabled just before it calls schedule. Reviewed: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.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/20170414084809.3dacde2a@gandalf.local.home Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds2017-05-101-1/+1
| | |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The main changes are: - Debloat RCU headers - Parallelize SRCU callback handling (plus overlapping patches) - Improve the performance of Tree SRCU on a CPU-hotplug stress test - Documentation updates - Miscellaneous fixes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (74 commits) rcu: Open-code the rcu_cblist_n_lazy_cbs() function rcu: Open-code the rcu_cblist_n_cbs() function rcu: Open-code the rcu_cblist_empty() function rcu: Separately compile large rcu_segcblist functions srcu: Debloat the <linux/rcu_segcblist.h> header srcu: Adjust default auto-expediting holdoff srcu: Specify auto-expedite holdoff time srcu: Expedite first synchronize_srcu() when idle srcu: Expedited grace periods with reduced memory contention srcu: Make rcutorture writer stalls print SRCU GP state srcu: Exact tracking of srcu_data structures containing callbacks srcu: Make SRCU be built by default srcu: Fix Kconfig botch when SRCU not selected rcu: Make non-preemptive schedule be Tasks RCU quiescent state srcu: Expedite srcu_schedule_cbs_snp() callback invocation srcu: Parallelize callback handling kvm: Move srcu_struct fields to end of struct kvm rcu: Fix typo in PER_RCU_NODE_PERIOD header comment rcu: Use true/false in assignment to bool rcu: Use bool value directly ...
| | | * \ \ Merge branch 'for-mingo' of ↵Ingo Molnar2017-04-231-1/+1
| | | |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU updates from Paul E. McKenney: - Documentation updates. - Miscellaneous fixes. - Parallelize SRCU callback handling (plus overlapping patches). Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | | * | | rcu: Make non-preemptive schedule be Tasks RCU quiescent statePaul E. McKenney2017-04-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, a call to schedule() acts as a Tasks RCU quiescent state only if a context switch actually takes place. However, just the call to schedule() guarantees that the calling task has moved off of whatever tracing trampoline that it might have been one previously. This commit therefore plumbs schedule()'s "preempt" parameter into rcu_note_context_switch(), which then records the Tasks RCU quiescent state, but only if this call to schedule() was -not- due to a preemption. To avoid adding overhead to the common-case context-switch path, this commit hides the rcu_note_context_switch() check under an existing non-common-case check. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | | | | Merge branch 'for-linus' of ↵Linus Torvalds2017-05-021-1/+1
| | |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: tty: fix comment for __tty_alloc_driver() init/main: properly align the multi-line comment init/main: Fix double "the" in comment Fix dead URLs to ftp.kernel.org drivers: Clean up duplicated email address treewide: Fix typo in xml/driver-api/basics.xml tools/testing/selftests/powerpc: remove redundant CFLAGS in Makefile: "-Wall -O2 -Wall" -> "-O2 -Wall" selftests/timers: Spelling s/privledges/privileges/ HID: picoLCD: Spelling s/REPORT_WRTIE_MEMORY/REPORT_WRITE_MEMORY/ net: phy: dp83848: Fix Typo UBI: Fix typos Documentation: ftrace.txt: Correct nice value of 120 priority net: fec: Fix typo in error msg and comment treewide: Fix typos in printk
| | | * | | | | treewide: Fix typo in xml/driver-api/basics.xmlMasanari Iida2017-03-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fix spelling typos found in Documentation/output/xml/driver-api/basics.xml. It is because the xml file was generated from comments in source, so I had to fix the comments. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
| | * | | | | | Merge branch 'for-linus' of ↵Linus Torvalds2017-05-021-0/+4
| | |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching Pull livepatch updates from Jiri Kosina: - a per-task consistency model is being added for architectures that support reliable stack dumping (extending this, currently rather trivial set, is currently in the works). This extends the nature of the types of patches that can be applied by live patching infrastructure. The code stems from the design proposal made [1] back in November 2014. It's a hybrid of SUSE's kGraft and RH's kpatch, combining advantages of both: it uses kGraft's per-task consistency and syscall barrier switching combined with kpatch's stack trace switching. There are also a number of fallback options which make it quite flexible. Most of the heavy lifting done by Josh Poimboeuf with help from Miroslav Benes and Petr Mladek [1] https://lkml.kernel.org/r/20141107140458.GA21774@suse.cz - module load time patch optimization from Zhou Chengming - a few assorted small fixes * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching: livepatch: add missing printk newlines livepatch: Cancel transition a safe way for immediate patches livepatch: Reduce the time of finding module symbols livepatch: make klp_mutex proper part of API livepatch: allow removal of a disabled patch livepatch: add /proc/<pid>/patch_state livepatch: change to a per-task consistency model livepatch: store function sizes livepatch: use kstrtobool() in enabled_store() livepatch: move patching functions into patch.c livepatch: remove unnecessary object loaded check livepatch: separate enabled and patched states livepatch/s390: add TIF_PATCH_PENDING thread flag livepatch/s390: reorganize TIF thread flag bits livepatch/powerpc: add TIF_PATCH_PENDING thread flag livepatch/x86: add TIF_PATCH_PENDING thread flag livepatch: create temporary klp_update_patch_state() stub x86/entry: define _TIF_ALLWORK_MASK flags explicitly stacktrace/x86: add function for detecting reliable stack traces
| | | * | | | | | livepatch: change to a per-task consistency modelJosh Poimboeuf2017-03-081-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change livepatch to use a basic per-task consistency model. This is the foundation which will eventually enable us to patch those ~10% of security patches which change function or data semantics. This is the biggest remaining piece needed to make livepatch more generally useful. This code stems from the design proposal made by Vojtech [1] in November 2014. It's a hybrid of kGraft and kpatch: it uses kGraft's per-task consistency and syscall barrier switching combined with kpatch's stack trace switching. There are also a number of fallback options which make it quite flexible. Patches are applied on a per-task basis, when the task is deemed safe to switch over. When a patch is enabled, livepatch enters into a transition state where tasks are converging to the patched state. Usually this transition state can complete in a few seconds. The same sequence occurs when a patch is disabled, except the tasks converge from the patched state to the unpatched state. An interrupt handler inherits the patched state of the task it interrupts. The same is true for forked tasks: the child inherits the patched state of the parent. Livepatch uses several complementary approaches to determine when it's safe to patch tasks: 1. The first and most effective approach is stack checking of sleeping tasks. If no affected functions are on the stack of a given task, the task is patched. In most cases this will patch most or all of the tasks on the first try. Otherwise it'll keep trying periodically. This option is only available if the architecture has reliable stacks (HAVE_RELIABLE_STACKTRACE). 2. The second approach, if needed, is kernel exit switching. A task is switched when it returns to user space from a system call, a user space IRQ, or a signal. It's useful in the following cases: a) Patching I/O-bound user tasks which are sleeping on an affected function. In this case you have to send SIGSTOP and SIGCONT to force it to exit the kernel and be patched. b) Patching CPU-bound user tasks. If the task is highly CPU-bound then it will get patched the next time it gets interrupted by an IRQ. c) In the future it could be useful for applying patches for architectures which don't yet have HAVE_RELIABLE_STACKTRACE. In this case you would have to signal most of the tasks on the system. However this isn't supported yet because there's currently no way to patch kthreads without HAVE_RELIABLE_STACKTRACE. 3. For idle "swapper" tasks, since they don't ever exit the kernel, they instead have a klp_update_patch_state() call in the idle loop which allows them to be patched before the CPU enters the idle state. (Note there's not yet such an approach for kthreads.) All the above approaches may be skipped by setting the 'immediate' flag in the 'klp_patch' struct, which will disable per-task consistency and patch all tasks immediately. This can be useful if the patch doesn't change any function or data semantics. Note that, even with this flag set, it's possible that some tasks may still be running with an old version of the function, until that function returns. There's also an 'immediate' flag in the 'klp_func' struct which allows you to specify that certain functions in the patch can be applied without per-task consistency. This might be useful if you want to patch a common function like schedule(), and the function change doesn't need consistency but the rest of the patch does. For architectures which don't have HAVE_RELIABLE_STACKTRACE, the user must set patch->immediate which causes all tasks to be patched immediately. This option should be used with care, only when the patch doesn't change any function or data semantics. In the future, architectures which don't have HAVE_RELIABLE_STACKTRACE may be allowed to use per-task consistency if we can come up with another way to patch kthreads. The /sys/kernel/livepatch/<patch>/transition file shows whether a patch is in transition. Only a single patch (the topmost patch on the stack) can be in transition at a given time. A patch can remain in transition indefinitely, if any of the tasks are stuck in the initial patch state. A transition can be reversed and effectively canceled by writing the opposite value to the /sys/kernel/livepatch/<patch>/enabled file while the transition is in progress. Then all the tasks will attempt to converge back to the original patch state. [1] https://lkml.kernel.org/r/20141107140458.GA21774@suse.cz Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Ingo Molnar <mingo@kernel.org> # for the scheduler changes Signed-off-by: Jiri Kosina <jkosina@suse.cz>
| | * | | | | | | Merge branch 'locking-core-for-linus' of ↵Linus Torvalds2017-05-011-11/+53
| | |\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "The main changes in this cycle were: - a big round of FUTEX_UNLOCK_PI improvements, fixes, cleanups and general restructuring - lockdep updates such as new checks for lock_downgrade() - introduce the new atomic_try_cmpxchg() locking API and use it to optimize refcount code generation - ... plus misc fixes, updates and cleanups" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits) MAINTAINERS: Add FUTEX SUBSYSTEM futex: Clarify mark_wake_futex memory barrier usage futex: Fix small (and harmless looking) inconsistencies futex: Avoid freeing an active timer rtmutex: Plug preempt count leak in rt_mutex_futex_unlock() rtmutex: Fix more prio comparisons rtmutex: Fix PI chain order integrity sched,tracing: Update trace_sched_pi_setprio() sched/rtmutex: Refactor rt_mutex_setprio() rtmutex: Clean up sched/deadline/rtmutex: Dont miss the dl_runtime/dl_period update sched/rtmutex/deadline: Fix a PI crash for deadline tasks rtmutex: Deboost before waking up the top waiter locking/ww-mutex: Limit stress test to 2 seconds locking/atomic: Fix atomic_try_cmpxchg() semantics lockdep: Fix per-cpu static objects futex: Drop hb->lock before enqueueing on the rtmutex futex: Futex_unlock_pi() determinism futex: Rework futex_lock_pi() to use rt_mutex_*_proxy_lock() futex,rt_mutex: Restructure rt_mutex_finish_proxy_lock() ...
| | | * \ \ \ \ \ \ Merge branch 'linus' into locking/core, to pick up fixesIngo Molnar2017-04-142-32/+34
| | | |\ \ \ \ \ \ \ | | | | | |_|/ / / / | | | | |/| | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched,tracing: Update trace_sched_pi_setprio()Peter Zijlstra2017-04-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pass the PI donor task, instead of a numerical priority. Numerical priorities are not sufficient to describe state ever since SCHED_DEADLINE. Annotate all sched tracepoints that are currently broken; fixing them will bork userspace. *hate*. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: juri.lelli@arm.com Cc: bigeasy@linutronix.de Cc: xlpang@redhat.com Cc: mathieu.desnoyers@efficios.com Cc: jdesfossez@efficios.com Cc: bristot@redhat.com Link: http://lkml.kernel.org/r/20170323150216.353599881@infradead.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | | * | | | | | | sched/rtmutex: Refactor rt_mutex_setprio()Peter Zijlstra2017-04-041-13/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the introduction of SCHED_DEADLINE the whole notion that priority is a single number is gone, therefore the @prio argument to rt_mutex_setprio() doesn't make sense anymore. So rework the code to pass a pi_task instead. Note this also fixes a problem with pi_top_task caching; previously we would not set the pointer (call rt_mutex_update_top_task) if the priority didn't change, this could lead to a stale pointer. As for the XXX, I think its fine to use pi_task->prio, because if it differs from waiter->prio, a PI chain update is immenent. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: juri.lelli@arm.com Cc: bigeasy@linutronix.de Cc: xlpang@redhat.com Cc: rostedt@goodmis.org Cc: mathieu.desnoyers@efficios.com Cc: jdesfossez@efficios.com Cc: bristot@redhat.com Link: http://lkml.kernel.org/r/20170323150216.303827095@infradead.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | | * | | | | | | sched/rtmutex/deadline: Fix a PI crash for deadline tasksXunlei Pang2017-04-041-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A crash happened while I was playing with deadline PI rtmutex. BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: [<ffffffff810eeb8f>] rt_mutex_get_top_task+0x1f/0x30 PGD 232a75067 PUD 230947067 PMD 0 Oops: 0000 [#1] SMP CPU: 1 PID: 10994 Comm: a.out Not tainted Call Trace: [<ffffffff810b658c>] enqueue_task+0x2c/0x80 [<ffffffff810ba763>] activate_task+0x23/0x30 [<ffffffff810d0ab5>] pull_dl_task+0x1d5/0x260 [<ffffffff810d0be6>] pre_schedule_dl+0x16/0x20 [<ffffffff8164e783>] __schedule+0xd3/0x900 [<ffffffff8164efd9>] schedule+0x29/0x70 [<ffffffff8165035b>] __rt_mutex_slowlock+0x4b/0xc0 [<ffffffff81650501>] rt_mutex_slowlock+0xd1/0x190 [<ffffffff810eeb33>] rt_mutex_timed_lock+0x53/0x60 [<ffffffff810ecbfc>] futex_lock_pi.isra.18+0x28c/0x390 [<ffffffff810ed8b0>] do_futex+0x190/0x5b0 [<ffffffff810edd50>] SyS_futex+0x80/0x180 This is because rt_mutex_enqueue_pi() and rt_mutex_dequeue_pi() are only protected by pi_lock when operating pi waiters, while rt_mutex_get_top_task(), will access them with rq lock held but not holding pi_lock. In order to tackle it, we introduce new "pi_top_task" pointer cached in task_struct, and add new rt_mutex_update_top_task() to update its value, it can be called by rt_mutex_setprio() which held both owner's pi_lock and rq lock. Thus "pi_top_task" can be safely accessed by enqueue_task_dl() under rq lock. Originally-From: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Xunlei Pang <xlpang@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: juri.lelli@arm.com Cc: bigeasy@linutronix.de Cc: mathieu.desnoyers@efficios.com Cc: jdesfossez@efficios.com Cc: bristot@redhat.com Link: http://lkml.kernel.org/r/20170323150216.157682758@infradead.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * | | | | | | | Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2017-05-016-291/+494
| | |\ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes in this cycle were: - another round of rq-clock handling debugging, robustization and fixes - PELT accounting improvements - CPU hotplug related ->cpus_allowed affinity handling fixes all around the tree - ... plus misc fixes, cleanups and updates" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits) sched/x86: Update reschedule warning text crypto: N2 - Replace racy task affinity logic cpufreq/sparc-us2e: Replace racy task affinity logic cpufreq/sparc-us3: Replace racy task affinity logic cpufreq/sh: Replace racy task affinity logic cpufreq/ia64: Replace racy task affinity logic ACPI/processor: Replace racy task affinity logic ACPI/processor: Fix error handling in __acpi_processor_start() sparc/sysfs: Replace racy task affinity logic powerpc/smp: Replace open coded task affinity logic ia64/sn/hwperf: Replace racy task affinity logic ia64/salinfo: Replace racy task affinity logic workqueue: Provide work_on_cpu_safe() ia64/topology: Remove cpus_allowed manipulation sched/fair: Move the PELT constants into a generated header sched/fair: Increase PELT accuracy for small tasks sched/fair: Fix comments sched/Documentation: Add 'sched-pelt' tool sched/fair: Fix corner case in __accumulate_sum() sched/core: Remove 'task' parameter and rename tsk_restore_flags() to current_restore_flags() ...
| | | * | | | | | | | sched/fair: Move the PELT constants into a generated headerPeter Zijlstra2017-04-142-18/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we have a tool to generate the PELT constants in C form, use its output as a separate header. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | | sched/fair: Increase PELT accuracy for small tasksPeter Zijlstra2017-04-141-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We truncate (and loose) the lower 10 bits of runtime in ___update_load_avg(), this means there's a consistent bias to under-account tasks. This is esp. significant for small tasks. Cure this by only forwarding last_update_time to the point we've actually accounted for, leaving the remainder for the next time. Reported-by: Morten Rasmussen <morten.rasmussen@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | | sched/fair: Fix commentsPeter Zijlstra2017-04-141-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Historically our periods (or p) argument in PELT denoted the number of full periods (what is now d2). However recent patches have changed this to the total decay (previously p+1), leading to a confusing discrepancy between comments and code. Try and clarify things by making periods (in code) and p (in comments) be the same thing (again). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | | sched/fair: Fix corner case in __accumulate_sum()Peter Zijlstra2017-04-141-56/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Paul noticed that in the (periods >= LOAD_AVG_MAX_N) case in __accumulate_sum(), the returned contribution value (LOAD_AVG_MAX) is incorrect. This is because at this point, the decay_load() on the old state -- the first step in accumulate_sum() -- will not have resulted in 0, and will therefore result in a sum larger than the maximum value of our series. Obviously broken. Note that: decay_load(LOAD_AVG_MAX, LOAD_AVG_MAX_N) = 1 (345 / 32) 47742 * - ^ = ~27 2 Not to mention that any further contribution from the d3 segment (our new period) would also push it over the maximum. Solve this by noting that we can write our c2 term: p c2 = 1024 \Sum y^n n=1 In terms of our maximum value: inf inf p max = 1024 \Sum y^n = 1024 ( \Sum y^n + \Sum y^n + y^0 ) n=0 n=p+1 n=1 Further note that: inf inf inf ( \Sum y^n ) y^p = \Sum y^(n+p) = \Sum y^n n=0 n=0 n=p Combined that gives us: p c2 = 1024 \Sum y^n n=1 inf inf = 1024 ( \Sum y^n - \Sum y^n - y^0 ) n=0 n=p+1 = max - (max y^(p+1)) - 1024 Further simplify things by dealing with p=0 early on. Reported-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yuyang Du <yuyang.du@intel.com> Cc: linux-kernel@vger.kernel.org Fixes: a481db34b9be ("sched/fair: Optimize ___update_sched_avg()") Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | | Merge tag 'v4.11-rc6' into sched/core, to pick up fixesIngo Molnar2017-04-112-32/+34
| | | |\ \ \ \ \ \ \ \ | | | | |/ / / / / / / | | | |/| / / / / / / | | | | |/ / / / / / Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched/fair: Optimize ___update_sched_avg()Yuyang Du2017-03-301-94/+118
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The main PELT function ___update_load_avg(), which implements the accumulation and progression of the geometric average series, is implemented along the following lines for the scenario where the time delta spans all 3 possible sections (see figure below): 1. add the remainder of the last incomplete period 2. decay old sum 3. accumulate new sum in full periods since last_update_time 4. accumulate the current incomplete period 5. update averages Or: d1 d2 d3 ^ ^ ^ | | | |<->|<----------------->|<--->| ... |---x---|------| ... |------|-----x (now) load_sum' = (load_sum + weight * scale * d1) * y^(p+1) + (1,2) p weight * scale * 1024 * \Sum y^n + (3) n=1 weight * scale * d3 * y^0 (4) load_avg' = load_sum' / LOAD_AVG_MAX (5) Where: d1 - is the delta part completing the remainder of the last incomplete period, d2 - is the delta part spannind complete periods, and d3 - is the delta part starting the current incomplete period. We can simplify the code in two steps; the first step is to separate the first term into new and old parts like: (load_sum + weight * scale * d1) * y^(p+1) = load_sum * y^(p+1) + weight * scale * d1 * y^(p+1) Once we've done that, its easy to see that all new terms carry the common factors: weight * scale If we factor those out, we arrive at the form: load_sum' = load_sum * y^(p+1) + weight * scale * (d1 * y^(p+1) + p 1024 * \Sum y^n + n=1 d3 * y^0) Which results in a simpler, smaller and faster implementation. Signed-off-by: Yuyang Du <yuyang.du@intel.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: bsegall@google.com Cc: dietmar.eggemann@arm.com Cc: matt@codeblueprint.co.uk Cc: morten.rasmussen@arm.com Cc: pjt@google.com Cc: umgwanakikbuti@gmail.com Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/1486935863-25251-3-git-send-email-yuyang.du@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched/fair: Explicitly generate __update_load_avg() instancesPeter Zijlstra2017-03-301-18/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __update_load_avg() function is an __always_inline because its used with constant propagation to generate different variants of the code without having to duplicate it (which would be prone to bugs). Explicitly instantiate the 3 variants. Note that most of this is called from rather hot paths, so reducing branches is good. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched/fair: Prefer sibiling only if local group is under-utilizedSrikar Dronamraju2017-03-271-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the child domain prefers tasks to go siblings, the local group could end up pulling tasks to itself even if the local group is almost equally loaded as the source group. Lets assume a 4 core,smt==2 machine running 5 thread ebizzy workload. Everytime, local group has capacity and source group has atleast 2 threads, local group tries to pull the task. This causes the threads to constantly move between different cores. This is even more profound if the cores have more threads, like in Power 8, smt 8 mode. Fix this by only allowing local group to pull a task, if the source group has more number of tasks than the local group. Here are the relevant perf stat numbers of a 22 core,smt 8 Power 8 machine. Without patch: Performance counter stats for 'ebizzy -t 22 -S 100' (5 runs): 1,440 context-switches # 0.001 K/sec ( +- 1.26% ) 366 cpu-migrations # 0.000 K/sec ( +- 5.58% ) 3,933 page-faults # 0.002 K/sec ( +- 11.08% ) Performance counter stats for 'ebizzy -t 48 -S 100' (5 runs): 6,287 context-switches # 0.001 K/sec ( +- 3.65% ) 3,776 cpu-migrations # 0.001 K/sec ( +- 4.84% ) 5,702 page-faults # 0.001 K/sec ( +- 9.36% ) Performance counter stats for 'ebizzy -t 96 -S 100' (5 runs): 8,776 context-switches # 0.001 K/sec ( +- 0.73% ) 2,790 cpu-migrations # 0.000 K/sec ( +- 0.98% ) 10,540 page-faults # 0.001 K/sec ( +- 3.12% ) With patch: Performance counter stats for 'ebizzy -t 22 -S 100' (5 runs): 1,133 context-switches # 0.001 K/sec ( +- 4.72% ) 123 cpu-migrations # 0.000 K/sec ( +- 3.42% ) 3,858 page-faults # 0.002 K/sec ( +- 8.52% ) Performance counter stats for 'ebizzy -t 48 -S 100' (5 runs): 2,169 context-switches # 0.000 K/sec ( +- 6.19% ) 189 cpu-migrations # 0.000 K/sec ( +- 12.75% ) 5,917 page-faults # 0.001 K/sec ( +- 8.09% ) Performance counter stats for 'ebizzy -t 96 -S 100' (5 runs): 5,333 context-switches # 0.001 K/sec ( +- 5.91% ) 506 cpu-migrations # 0.000 K/sec ( +- 3.35% ) 10,792 page-faults # 0.001 K/sec ( +- 7.75% ) Which show that in these workloads CPU migrations get reduced significantly. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincent Guittot <vincent.guittot@linaro.org> Link: http://lkml.kernel.org/r/1490205470-10249-1-git-send-email-srikar@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched/fair: Fix FTQ noise bench regressionVincent Guittot2017-03-231-3/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A regression of the FTQ noise has been reported by Ying Huang, on the following hardware: 8 threads Intel(R) Core(TM)i7-4770 CPU @ 3.40GHz with 8G memory ... which was caused by this commit: commit 4e5160766fcc ("sched/fair: Propagate asynchrous detach") The only part of the patch that can increase the noise is the update of blocked load of group entity in update_blocked_averages(). We can optimize this call and skip the update of group entity if its load and utilization are already null and there is no pending propagation of load in the task group. This optimization partly restores the noise score. A more agressive optimization has been tried but has shown worse score. Reported-by: ying.huang@linux.intel.com Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dietmar.eggemann@arm.com Cc: ying.huang@intel.com Fixes: 4e5160766fcc ("sched/fair: Propagate asynchrous detach") Link: http://lkml.kernel.org/r/1489758442-2877-1-git-send-email-vincent.guittot@linaro.org [ Fixed typos, improved layout. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched/core: Fix rq lock pinning warning after call balance callbacksWanpeng Li2017-03-231-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This can be reproduced by running rt-migrate-test: WARNING: CPU: 2 PID: 2195 at kernel/locking/lockdep.c:3670 lock_unpin_lock() unpinning an unpinned lock ... Call Trace: dump_stack() __warn() warn_slowpath_fmt() lock_unpin_lock() __balance_callback() __schedule() schedule() futex_wait_queue_me() futex_wait() do_futex() SyS_futex() do_syscall_64() entry_SYSCALL64_slow_path() Revert the rq_lock_irqsave() usage here, the whole point of the balance_callback() was to allow dropping rq->lock. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 8a8c69c32778 ("sched/core: Add rq->lock wrappers") Link: http://lkml.kernel.org/r/1489718719-3951-1-git-send-email-wanpeng.li@hotmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched/core: Avoid double update_rq_clock() in move_queued_task()Peter Zijlstra2017-03-161-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Address this case: WARNING: CPU: 0 PID: 2070 at ../kernel/sched/core.c:109 update_rq_clock+0x74/0x80 rq->clock_update_flags & RQCF_UPDATED Call Trace: update_rq_clock() move_queued_task() __set_cpus_allowed_ptr() ... Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched/core: Fix double update_rq_clock) calls in attach_task()/detach_task()Peter Zijlstra2017-03-161-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched/core: Avoid obvious double update_rq_clock()Peter Zijlstra2017-03-161-8/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add DEQUEUE_NOCLOCK to all places where we just did an update_rq_clock() already. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched/core: Simplify update_rq_clock() in __schedule()Peter Zijlstra2017-03-161-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of relying on deactivate_task() to call update_rq_clock() and handling the case where it didn't happen (task_on_rq_queued), unconditionally do update_rq_clock() and skip any further updates. This also avoids a double update on deactivate_task() + ttwu_local(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched/core: Make sched_ttwu_pending() atomic in timePeter Zijlstra2017-03-161-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since all tasks on the wake_list are woken under a single rq->lock avoid calling update_rq_clock() for each task. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched/core: Add ENQUEUE_NOCLOCK to ENQUEUE_RESTOREPeter Zijlstra2017-03-161-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In all cases, ENQUEUE_RESTORE should also have ENQUEUE_NOCLOCK because DEQUEUE_SAVE will have done an update_rq_clock(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched/core: Add {EN,DE}QUEUE_NOCLOCK flagsPeter Zijlstra2017-03-162-5/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently {en,de}queue_task() do an unconditional update_rq_clock(). However since we want to avoid duplicate updates, so that each rq->lock section appears atomic in time, we need to be able to skip these clock updates. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched/core: Add rq->lock wrappersPeter Zijlstra2017-03-163-112/+171
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The missing update_rq_clock() check can work with partial rq->lock wrappery, since a missing wrapper can cause the warning to not be emitted when it should have, but cannot cause the warning to trigger when it should not have. The duplicate update_rq_clock() check however can cause false warnings to trigger. Therefore add more comprehensive rq->lock wrappery. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched/core: Add WARNING for multiple update_rq_clock() callsPeter Zijlstra2017-03-162-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we have no missing calls, add a warning to find multiple calls. By having only a single update_rq_clock() call per rq-lock section, the section appears 'atomic' wrt time. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | * | | | | | | sched/rt: Add comments describing the RT IPI pull methodSteven Rostedt (VMware)2017-03-161-0/+81
| | | | |_|/ / / / | | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While looking into optimizations for the RT scheduler IPI logic, I realized that the comments are lacking to describe it efficiently. It deserves a lengthy description describing its design. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Clark Williams <williams@redhat.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170228155030.30c69068@gandalf.local.home [ Small typographical edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | | | | Merge tag 'pm-4.12-rc1' of ↵Linus Torvalds2017-05-011-28/+54
| | |\ \ \ \ \ \ \ | | | | |_|_|_|/ / | | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "This time the majority of changes go to the cpufreq subsystem (and to the intel_pstate driver in particular) and there are some updates in the generic power domains framework, cpuidle, tools and a couple of other places. One thing worth mentioning is that the intel_pstate's sysfs interface has been reworked to be more consistent with the general expectations of the cpufreq core and less confusing, hopefully for the better. Also, we have a new cpufreq driver for Tegra186 and new hardware support in intel_pstata and the Mediatek cpufreq driver. Apart from that, the AnalyzeSuspend utility for system suspend profiling gets a companion called AnalyzeBoot for the analogous profiling of system boot and they both go into one place under tools/power/pm-graph/. The rest is mostly fixes, cleanups and code reorganization. Specifics: - Rework the intel_pstate driver's sysfs interface to make it more straightforward and more intuitive (Rafael Wysocki). - Make intel_pstate support all processors which advertise HWP (hardware-managed P-states) to the kernel in all operation modes and make it use the load-based P-state selection algorithm on a wider range of systems in the active mode (Rafael Wysocki). - Add cpufreq driver for Tegra186 (Mikko Perttunen). - Add support for Gemini Lake SoCs to intel_pstate (David Box). - Add support for MT8176 and MT817x to the Mediatek cpufreq driver and clean up that driver a bit (Daniel Kurtz). - Clean up intel_pstate and optimize it slightly (Rafael Wysocki). - Update the schedutil cpufreq governor, mostly to fix a couple of issues with it related to specific workloads, and rework its sysfs tunable and initialization a bit (Rafael Wysocki, Viresh Kumar). - Fix minor issues in the imx6q, dbx500 and qoriq cpufreq drivers (Christophe Jaillet, Irina Tirdea, Leonard Crestez, Viresh Kumar, YuanTian Tang). - Add file patterns for cpufreq DT bindings to MAINTAINERS (Geert Uytterhoeven). - Add support for "always on" power domains to the genpd (generic power domains) framework and clean up that code somewhat (Ulf Hansson, Lina Iyer, Viresh Kumar). - Fix minor issues in the powernv cpuidle driver and clean it up (Anton Blanchard, Gautham Shenoy). - Move the AnalyzeSuspend utility under tools/power/pm-graph/ and add an analogous boot-profiling utility called AnalyzeBoot to it (Todd Brandt). - Add rk3328 support to the rockchip-io AVS (Adaptive Voltage Scaling) driver (David Wu). - Fix minor issues in the cpuidle core, the intel_pstate_tracer utility, the devfreq framework and the PM core documentation (Chanwoo Choi, Doug Smythies, Johan Hovold, Marcin Nowakowski)" * tag 'pm-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (56 commits) PM / runtime: Document autosuspend-helper side effects PM / runtime: Fix autosuspend documentation tools: power: pm-graph: Package makefile and man pages tools: power: pm-graph: AnalyzeBoot v2.0 tools: power: pm-graph: AnalyzeSuspend v4.6 cpufreq: Add Tegra186 cpufreq driver cpufreq: imx6q: Fix error handling code cpufreq: imx6q: Set max suspend_freq to avoid changes during suspend cpufreq: imx6q: Fix handling EPROBE_DEFER from regulator cpuidle: powernv: Avoid a branch in the core snooze_loop() loop cpuidle: powernv: Don't continually set thread priority in snooze_loop() cpuidle: powernv: Don't bounce between low and very low thread priority cpuidle: cpuidle-cps: remove unused variable tools/power/x86/intel_pstate_tracer: Adjust directory ownership cpufreq: schedutil: Use policy-dependent transition delays cpufreq: schedutil: Reduce frequencies slower PM / devfreq: Move struct devfreq_governor to devfreq directory PM / Domains: Ignore domain-idle-states that are not compatible cpufreq: intel_pstate: Add support for Gemini Lake powernv-cpuidle: Validate DT property array size ...
| | * | | | | | | Merge branch 'for-4.12' of ↵Linus Torvalds2017-05-011-2/+2
| | |\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Nothing major. Two notable fixes are Li's second stab at fixing the long-standing race condition in the mount path and suppression of spurious warning from cgroup_get(). All other changes are trivial" * 'for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: mark cgroup_get() with __maybe_unused cgroup: avoid attaching a cgroup root to two different superblocks, take 2 cgroup: fix spurious warnings on cgroup_is_dead() from cgroup_sk_alloc() cgroup: move cgroup_subsys_state parent field for cache locality cpuset: Remove cpuset_update_active_cpus()'s parameter. cgroup: switch to BUG_ON() cgroup: drop duplicate header nsproxy.h kernel: convert css_set.refcount from atomic_t to refcount_t kernel: convert cgroup_namespace.count from atomic_t to refcount_t
| | | * | | | | | | cpuset: Remove cpuset_update_active_cpus()'s parameter.Rakib Mullick2017-04-111-2/+2
| | | | |_|_|/ / / | | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In cpuset_update_active_cpus(), cpu_online isn't used anymore. Remove it. Signed-off-by: Rakib Mullick<rakib.mullick@gmail.com> Acked-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| | * | | | | | | sched/cputime: Fix ksoftirqd cputime accounting regressionFrederic Weisbecker2017-04-272-13/+23
| | | |_|_|/ / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | irq_time_read() returns the irqtime minus the ksoftirqd time. This is necessary because irq_time_read() is used to substract the IRQ time from the sum_exec_runtime of a task. If we were to include the softirq time of ksoftirqd, this task would substract its own CPU time everytime it updates ksoftirqd->sum_exec_runtime which would therefore never progress. But this behaviour got broken by: a499a5a14db ("sched/cputime: Increment kcpustat directly on irqtime account") ... which now includes ksoftirqd softirq time in the time returned by irq_time_read(). This has resulted in wrong ksoftirqd cputime reported to userspace through /proc/stat and thus "top" not showing ksoftirqd when it should after intense networking load. ksoftirqd->stime happens to be correct but it gets scaled down by sum_exec_runtime through task_cputime_adjusted(). To fix this, just account the strict IRQ time in a separate counter and use it to report the IRQ time. Reported-and-tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1493129448-5356-1-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | | | | | Revert "cpufreq: schedutil: Reduce frequencies slower"Rafael J. Wysocki2017-06-121-3/+0
| |_|_|/ / / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Revert commit 39b64aa1c007 (cpufreq: schedutil: Reduce frequencies slower) that introduced unintentional changes in behavior leading to adverse effects on some systems. Reported-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | | | | | | Merge schedutil governor updates for v4.12.Rafael J. Wysocki2017-04-281-28/+54
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| * | | | | cpufreq: schedutil: Use policy-dependent transition delaysRafael J. Wysocki2017-04-171-5/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make the schedutil governor take the initial (default) value of the rate_limit_us sysfs attribute from the (new) transition_delay_us policy parameter (to be set by the scaling driver). That will allow scaling drivers to make schedutil use smaller default values of rate_limit_us and reduce the default average time interval between consecutive frequency changes. Make intel_pstate set transition_delay_us to 500. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
| * | | | | cpufreq: schedutil: Reduce frequencies slowerRafael J. Wysocki2017-04-131-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The schedutil governor reduces frequencies too fast in some situations which cases undesirable performance drops to appear. To address that issue, make schedutil reduce the frequency slower by setting it to the average of the value chosen during the previous iteration of governor computations and the new one coming from its frequency selection formula. Link: https://bugzilla.kernel.org/show_bug.cgi?id=194963 Reported-by: John <john.ettedgui@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
| * | | | | Merge back schedutil governor updates for 4.12.Rafael J. Wysocki2017-03-251-23/+41
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| | * | | | cpufreq: schedutil: Trace frequency only if it has changedRafael J. Wysocki2017-03-241-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sugov_update_commit() calls trace_cpu_frequency() to record the current CPU frequency if it has not changed in the fast switch case to prevent utilities from getting confused (they may report that the CPU is idle if the frequency has not been recorded for too long, for example). However, that may cause the tracepoint to be triggered quite often for no real reason (if the frequency doesn't change, we will not modify the last update time stamp and governor computations may run again shortly when that happens), so don't do that (arguably, it is done to work around a utilities bug anyway). That allows code duplication in sugov_update_commit() to be reduced somewhat too. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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