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* Merge branch 'x86/hyperv' of ↵Radim Krčmář2018-02-0185-2142/+2337
|\ | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Topic branch for stable KVM clockource under Hyper-V. Thanks to Christoffer Dall for resolving the ARM conflict.
| * Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2018-01-306-151/+321
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes in this cycle were: - Implement frequency/CPU invariance and OPP selection for SCHED_DEADLINE (Juri Lelli) - Tweak the task migration logic for better multi-tasking workload scalability (Mel Gorman) - Misc cleanups, fixes and improvements" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/deadline: Make bandwidth enforcement scale-invariant sched/cpufreq: Move arch_scale_{freq,cpu}_capacity() outside of #ifdef CONFIG_SMP sched/cpufreq: Remove arch_scale_freq_capacity()'s 'sd' parameter sched/cpufreq: Always consider all CPUs when deciding next freq sched/cpufreq: Split utilization signals sched/cpufreq: Change the worker kthread to SCHED_DEADLINE sched/deadline: Move CPU frequency selection triggering points sched/cpufreq: Use the DEADLINE utilization signal sched/deadline: Implement "runtime overrun signal" support sched/fair: Only immediately migrate tasks due to interrupts if prev and target CPUs share cache sched/fair: Correct obsolete comment about cpufreq_update_util() sched/fair: Remove impossible condition from find_idlest_group_cpu() sched/cpufreq: Don't pass flags to sugov_set_iowait_boost() sched/cpufreq: Initialize sg_cpu->flags to 0 sched/fair: Consider RT/IRQ pressure in capacity_spare_wake() sched/fair: Use 'unsigned long' for utilization, consistently sched/core: Rework and clarify prepare_lock_switch() sched/fair: Remove unused 'curr' parameter from wakeup_gran sched/headers: Constify object_is_on_stack()
| | * sched/deadline: Make bandwidth enforcement scale-invariantJuri Lelli2018-01-103-6/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Apply frequency and CPU scale-invariance correction factor to bandwidth enforcement (similar to what we already do to fair utilization tracking). Each delta_exec gets scaled considering current frequency and maximum CPU capacity; which means that the reservation runtime parameter (that need to be specified profiling the task execution at max frequency on biggest capacity core) gets thus scaled accordingly. Signed-off-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: alessio.balsini@arm.com Cc: bristot@redhat.com Cc: dietmar.eggemann@arm.com Cc: joelaf@google.com Cc: juri.lelli@redhat.com Cc: mathieu.poirier@linaro.org Cc: morten.rasmussen@arm.com Cc: patrick.bellasi@arm.com Cc: rjw@rjwysocki.net Cc: rostedt@goodmis.org Cc: tkjos@android.com Cc: tommaso.cucinotta@santannapisa.it Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/20171204102325.5110-9-juri.lelli@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/cpufreq: Move arch_scale_{freq,cpu}_capacity() outside of #ifdef ↵Juri Lelli2018-01-101-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CONFIG_SMP Currently, frequency and cpu capacity scaling is only performed on CONFIG_SMP systems (as CFS PELT signals are only present for such systems). However, other scheduling classes want to do freq/cpu scaling, and for !CONFIG_SMP configurations as well. arch_scale_freq_capacity() is useful to implement frequency scaling even on !CONFIG_SMP platforms, so we simply move it outside CONFIG_SMP ifdeffery. Even if arch_scale_cpu_capacity() is not useful on !CONFIG_SMP platforms, we make a default implementation available for such configurations anyway to simplify scheduler code doing CPU scale invariance. Signed-off-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: alessio.balsini@arm.com Cc: bristot@redhat.com Cc: claudio@evidence.eu.com Cc: dietmar.eggemann@arm.com Cc: joelaf@google.com Cc: juri.lelli@redhat.com Cc: luca.abeni@santannapisa.it Cc: mathieu.poirier@linaro.org Cc: morten.rasmussen@arm.com Cc: patrick.bellasi@arm.com Cc: rjw@rjwysocki.net Cc: tkjos@android.com Cc: tommaso.cucinotta@santannapisa.it Cc: vincent.guittot@linaro.org Cc: viresh.kumar@linaro.org Link: http://lkml.kernel.org/r/20171204102325.5110-8-juri.lelli@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/cpufreq: Remove arch_scale_freq_capacity()'s 'sd' parameterJuri Lelli2018-01-102-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 'sd' parameter is never used in arch_scale_freq_capacity() (and it's hard to see where information coming from scheduling domains might help doing frequency invariance scaling). Remove it; also in anticipation of moving arch_scale_freq_capacity() outside CONFIG_SMP. Signed-off-by: Juri Lelli <juri.lelli@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: alessio.balsini@arm.com Cc: bristot@redhat.com Cc: claudio@evidence.eu.com Cc: dietmar.eggemann@arm.com Cc: joelaf@google.com Cc: juri.lelli@redhat.com Cc: luca.abeni@santannapisa.it Cc: mathieu.poirier@linaro.org Cc: morten.rasmussen@arm.com Cc: patrick.bellasi@arm.com Cc: rjw@rjwysocki.net Cc: rostedt@goodmis.org Cc: tkjos@android.com Cc: tommaso.cucinotta@santannapisa.it Cc: vincent.guittot@linaro.org Cc: viresh.kumar@linaro.org Link: http://lkml.kernel.org/r/20171204102325.5110-7-juri.lelli@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/cpufreq: Always consider all CPUs when deciding next freqJuri Lelli2018-01-101-6/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No assumption can be made upon the rate at which frequency updates get triggered, as there are scheduling policies (like SCHED_DEADLINE) which don't trigger them so frequently. Remove such assumption from the code, by always considering SCHED_DEADLINE utilization signal as not stale. Signed-off-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: alessio.balsini@arm.com Cc: bristot@redhat.com Cc: dietmar.eggemann@arm.com Cc: joelaf@google.com Cc: juri.lelli@redhat.com Cc: mathieu.poirier@linaro.org Cc: morten.rasmussen@arm.com Cc: patrick.bellasi@arm.com Cc: rjw@rjwysocki.net Cc: rostedt@goodmis.org Cc: tkjos@android.com Cc: tommaso.cucinotta@santannapisa.it Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/20171204102325.5110-6-juri.lelli@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/cpufreq: Split utilization signalsJuri Lelli2018-01-101-14/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To be able to treat utilization signals of different scheduling classes in different ways (e.g., CFS signal might be stale while DEADLINE signal is never stale by design) we need to split sugov_cpu::util signal in two: util_cfs and util_dl. This patch does that by also changing sugov_get_util() parameter list. After this change, aggregation of the different signals has to be performed by sugov_get_util() users (so that they can decide what to do with the different signals). Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: alessio.balsini@arm.com Cc: bristot@redhat.com Cc: dietmar.eggemann@arm.com Cc: joelaf@google.com Cc: juri.lelli@redhat.com Cc: mathieu.poirier@linaro.org Cc: morten.rasmussen@arm.com Cc: patrick.bellasi@arm.com Cc: rjw@rjwysocki.net Cc: rostedt@goodmis.org Cc: tkjos@android.com Cc: tommaso.cucinotta@santannapisa.it Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/20171204102325.5110-5-juri.lelli@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/cpufreq: Change the worker kthread to SCHED_DEADLINEJuri Lelli2018-01-104-36/+129
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Worker kthread needs to be able to change frequency for all other threads. Make it special, just under STOP class. Signed-off-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: alessio.balsini@arm.com Cc: bristot@redhat.com Cc: dietmar.eggemann@arm.com Cc: joelaf@google.com Cc: juri.lelli@redhat.com Cc: mathieu.poirier@linaro.org Cc: morten.rasmussen@arm.com Cc: patrick.bellasi@arm.com Cc: rjw@rjwysocki.net Cc: rostedt@goodmis.org Cc: tkjos@android.com Cc: tommaso.cucinotta@santannapisa.it Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/20171204102325.5110-4-juri.lelli@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/deadline: Move CPU frequency selection triggering pointsJuri Lelli2018-01-102-9/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since SCHED_DEADLINE doesn't track utilization signal (but reserves a fraction of CPU bandwidth to tasks admitted to the system), there is no point in evaluating frequency changes during each tick event. Move frequency selection triggering points to where running_bw changes. Co-authored-by: Claudio Scordino <claudio@evidence.eu.com> Signed-off-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: alessio.balsini@arm.com Cc: bristot@redhat.com Cc: dietmar.eggemann@arm.com Cc: joelaf@google.com Cc: juri.lelli@redhat.com Cc: mathieu.poirier@linaro.org Cc: morten.rasmussen@arm.com Cc: patrick.bellasi@arm.com Cc: rjw@rjwysocki.net Cc: rostedt@goodmis.org Cc: tkjos@android.com Cc: tommaso.cucinotta@santannapisa.it Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/20171204102325.5110-3-juri.lelli@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/cpufreq: Use the DEADLINE utilization signalJuri Lelli2018-01-102-10/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SCHED_DEADLINE tracks active utilization signal with a per dl_rq variable named running_bw. Make use of that to drive CPU frequency selection: add up FAIR and DEADLINE contribution to get the required CPU capacity to handle both requirements (while RT still selects max frequency). Co-authored-by: Claudio Scordino <claudio@evidence.eu.com> Signed-off-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: alessio.balsini@arm.com Cc: bristot@redhat.com Cc: dietmar.eggemann@arm.com Cc: joelaf@google.com Cc: juri.lelli@redhat.com Cc: mathieu.poirier@linaro.org Cc: morten.rasmussen@arm.com Cc: patrick.bellasi@arm.com Cc: rjw@rjwysocki.net Cc: rostedt@goodmis.org Cc: tkjos@android.com Cc: tommaso.cucinotta@santannapisa.it Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/20171204102325.5110-2-juri.lelli@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/deadline: Implement "runtime overrun signal" supportJuri Lelli2018-01-103-2/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the possibility of getting the delivery of a SIGXCPU signal whenever there is a runtime overrun. The request is done through the sched_flags field within the sched_attr structure. Forward port of https://lkml.org/lkml/2009/10/16/170 Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Claudio Scordino <claudio@evidence.eu.com> Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it> 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: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1513077024-25461-1-git-send-email-claudio@evidence.eu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/fair: Only immediately migrate tasks due to interrupts if prev and ↵Mel Gorman2018-01-101-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | target CPUs share cache If waking from an idle CPU due to an interrupt then it's possible that the waker task will be pulled to wake on the current CPU. Unfortunately, depending on the type of interrupt and IRQ configuration, there may not be a strong relationship between the CPU an interrupt was delivered on and the CPU a task was running on. For example, the interrupts could all be delivered to CPUs on one particular node due to the machine topology or IRQ affinity configuration. Another example is an interrupt for an IO completion which can be delivered to any CPU where there is no guarantee the data is either cache hot or even local. This patch was motivated by the observation that an IO workload was being pulled cross-node on a frequent basis when IO completed. From a wakeup latency perspective, it's still useful to know that an idle CPU is immediately available for use but lets only consider an automatic migration if the CPUs share cache to limit damage due to NUMA migrations. Migrations may still occur if wake_affine_weight determines it's appropriate. These are the throughput results for dbench running on ext4 comparing 4.15-rc3 and this patch on a 2-socket machine where interrupts due to IO completions can happen on any CPU. 4.15.0-rc3 4.15.0-rc3 vanilla lessmigrate Hmean 1 854.64 ( 0.00%) 865.01 ( 1.21%) Hmean 2 1229.60 ( 0.00%) 1274.44 ( 3.65%) Hmean 4 1591.81 ( 0.00%) 1628.08 ( 2.28%) Hmean 8 1845.04 ( 0.00%) 1831.80 ( -0.72%) Hmean 16 2038.61 ( 0.00%) 2091.44 ( 2.59%) Hmean 32 2327.19 ( 0.00%) 2430.29 ( 4.43%) Hmean 64 2570.61 ( 0.00%) 2568.54 ( -0.08%) Hmean 128 2481.89 ( 0.00%) 2499.28 ( 0.70%) Stddev 1 14.31 ( 0.00%) 5.35 ( 62.65%) Stddev 2 21.29 ( 0.00%) 11.09 ( 47.92%) Stddev 4 7.22 ( 0.00%) 6.80 ( 5.92%) Stddev 8 26.70 ( 0.00%) 9.41 ( 64.76%) Stddev 16 22.40 ( 0.00%) 20.01 ( 10.70%) Stddev 32 45.13 ( 0.00%) 44.74 ( 0.85%) Stddev 64 93.10 ( 0.00%) 93.18 ( -0.09%) Stddev 128 184.28 ( 0.00%) 177.85 ( 3.49%) Note the small increase in throughput for low thread counts but also note that the standard deviation for each sample during the test run is lower. The throughput figures for dbench can be misleading so the benchmark is actually modified to time the latency of the processing of one load file with many samples taken. The difference in latency is 4.15.0-rc3 4.15.0-rc3 vanilla lessmigrate Amean 1 21.71 ( 0.00%) 21.47 ( 1.08%) Amean 2 30.89 ( 0.00%) 29.58 ( 4.26%) Amean 4 47.54 ( 0.00%) 46.61 ( 1.97%) Amean 8 82.71 ( 0.00%) 82.81 ( -0.12%) Amean 16 149.45 ( 0.00%) 145.01 ( 2.97%) Amean 32 265.49 ( 0.00%) 248.43 ( 6.42%) Amean 64 463.23 ( 0.00%) 463.55 ( -0.07%) Amean 128 933.97 ( 0.00%) 935.50 ( -0.16%) Stddev 1 1.58 ( 0.00%) 1.54 ( 2.26%) Stddev 2 2.84 ( 0.00%) 2.95 ( -4.15%) Stddev 4 6.78 ( 0.00%) 6.85 ( -0.99%) Stddev 8 16.85 ( 0.00%) 16.37 ( 2.85%) Stddev 16 41.59 ( 0.00%) 41.04 ( 1.32%) Stddev 32 111.05 ( 0.00%) 105.11 ( 5.35%) Stddev 64 285.94 ( 0.00%) 288.01 ( -0.72%) Stddev 128 803.39 ( 0.00%) 809.73 ( -0.79%) It's a small improvement which is not surprising given that migrations that migrate to a different node as not that common. However, it is noticeable in the CPU migration statistics which are reduced by 24%. There was a query for v1 of this patch about NAS so here are the results for C-class using MPI for parallelisation on the same machine nas-mpi 4.15.0-rc3 4.15.0-rc3 vanilla noirq Time cg.C 24.25 ( 0.00%) 23.17 ( 4.45%) Time ep.C 8.22 ( 0.00%) 8.29 ( -0.85%) Time ft.C 22.67 ( 0.00%) 20.34 ( 10.28%) Time is.C 1.42 ( 0.00%) 1.47 ( -3.52%) Time lu.C 55.62 ( 0.00%) 54.81 ( 1.46%) Time mg.C 7.93 ( 0.00%) 7.91 ( 0.25%) 4.15.0-rc3 4.15.0-rc3 vanilla noirq-v1r1 User 3799.96 3748.34 System 672.10 626.15 Elapsed 91.91 79.49 lu.C sees a small gain, ft.C a large gain and ep.C and is.C see small regressions but in terms of absolute time, the difference is small and likely within run-to-run variance. System CPU usage is slightly reduced. schbench from Facebook was also requested. This is a bit of a mixed bag but it's important to note that this workload should not be heavily impacted by wakeups from interrupt context. 4.15.0-rc3 4.15.0-rc3 vanilla noirq-v1r1 Lat 50.00th-qrtle-1 41.00 ( 0.00%) 41.00 ( 0.00%) Lat 75.00th-qrtle-1 42.00 ( 0.00%) 42.00 ( 0.00%) Lat 90.00th-qrtle-1 43.00 ( 0.00%) 44.00 ( -2.33%) Lat 95.00th-qrtle-1 44.00 ( 0.00%) 46.00 ( -4.55%) Lat 99.00th-qrtle-1 57.00 ( 0.00%) 58.00 ( -1.75%) Lat 99.50th-qrtle-1 59.00 ( 0.00%) 59.00 ( 0.00%) Lat 99.90th-qrtle-1 67.00 ( 0.00%) 78.00 ( -16.42%) Lat 50.00th-qrtle-2 40.00 ( 0.00%) 51.00 ( -27.50%) Lat 75.00th-qrtle-2 45.00 ( 0.00%) 56.00 ( -24.44%) Lat 90.00th-qrtle-2 53.00 ( 0.00%) 59.00 ( -11.32%) Lat 95.00th-qrtle-2 57.00 ( 0.00%) 61.00 ( -7.02%) Lat 99.00th-qrtle-2 67.00 ( 0.00%) 71.00 ( -5.97%) Lat 99.50th-qrtle-2 69.00 ( 0.00%) 74.00 ( -7.25%) Lat 99.90th-qrtle-2 83.00 ( 0.00%) 77.00 ( 7.23%) Lat 50.00th-qrtle-4 51.00 ( 0.00%) 51.00 ( 0.00%) Lat 75.00th-qrtle-4 57.00 ( 0.00%) 56.00 ( 1.75%) Lat 90.00th-qrtle-4 60.00 ( 0.00%) 59.00 ( 1.67%) Lat 95.00th-qrtle-4 62.00 ( 0.00%) 62.00 ( 0.00%) Lat 99.00th-qrtle-4 73.00 ( 0.00%) 72.00 ( 1.37%) Lat 99.50th-qrtle-4 76.00 ( 0.00%) 74.00 ( 2.63%) Lat 99.90th-qrtle-4 85.00 ( 0.00%) 78.00 ( 8.24%) Lat 50.00th-qrtle-8 54.00 ( 0.00%) 58.00 ( -7.41%) Lat 75.00th-qrtle-8 59.00 ( 0.00%) 62.00 ( -5.08%) Lat 90.00th-qrtle-8 65.00 ( 0.00%) 66.00 ( -1.54%) Lat 95.00th-qrtle-8 67.00 ( 0.00%) 70.00 ( -4.48%) Lat 99.00th-qrtle-8 78.00 ( 0.00%) 79.00 ( -1.28%) Lat 99.50th-qrtle-8 81.00 ( 0.00%) 80.00 ( 1.23%) Lat 99.90th-qrtle-8 116.00 ( 0.00%) 83.00 ( 28.45%) Lat 50.00th-qrtle-16 65.00 ( 0.00%) 64.00 ( 1.54%) Lat 75.00th-qrtle-16 77.00 ( 0.00%) 71.00 ( 7.79%) Lat 90.00th-qrtle-16 83.00 ( 0.00%) 82.00 ( 1.20%) Lat 95.00th-qrtle-16 87.00 ( 0.00%) 87.00 ( 0.00%) Lat 99.00th-qrtle-16 95.00 ( 0.00%) 96.00 ( -1.05%) Lat 99.50th-qrtle-16 99.00 ( 0.00%) 103.00 ( -4.04%) Lat 99.90th-qrtle-16 104.00 ( 0.00%) 122.00 ( -17.31%) Lat 50.00th-qrtle-32 71.00 ( 0.00%) 73.00 ( -2.82%) Lat 75.00th-qrtle-32 91.00 ( 0.00%) 92.00 ( -1.10%) Lat 90.00th-qrtle-32 108.00 ( 0.00%) 107.00 ( 0.93%) Lat 95.00th-qrtle-32 118.00 ( 0.00%) 115.00 ( 2.54%) Lat 99.00th-qrtle-32 134.00 ( 0.00%) 129.00 ( 3.73%) Lat 99.50th-qrtle-32 138.00 ( 0.00%) 133.00 ( 3.62%) Lat 99.90th-qrtle-32 149.00 ( 0.00%) 146.00 ( 2.01%) Lat 50.00th-qrtle-39 83.00 ( 0.00%) 81.00 ( 2.41%) Lat 75.00th-qrtle-39 105.00 ( 0.00%) 102.00 ( 2.86%) Lat 90.00th-qrtle-39 120.00 ( 0.00%) 119.00 ( 0.83%) Lat 95.00th-qrtle-39 129.00 ( 0.00%) 128.00 ( 0.78%) Lat 99.00th-qrtle-39 153.00 ( 0.00%) 149.00 ( 2.61%) Lat 99.50th-qrtle-39 166.00 ( 0.00%) 156.00 ( 6.02%) Lat 99.90th-qrtle-39 12304.00 ( 0.00%) 12848.00 ( -4.42%) When heavily loaded (e.g. 99.50th-qrtle-39 indicates 39 threads), there are small gains in many cases. Otherwise it depends on the quartile used where it can be bad -- e.g. 75.00th-qrtle-2. However, even these results are probably a co-incidence. For this workload, much depends on what node the threads get placed on and their relative locality and not wakeups from interrupt context. A larger component on how it behaves would be automatic NUMA balancing where a fault incurred to measure locality would be a much larger contributer to latency than the wakeup path. This is the results from an almost identical machine that happened to run the same test. They only differ in terms of storage which is irrelevant for this test. 4.15.0-rc3 4.15.0-rc3 vanilla noirq-v1r1 Lat 50.00th-qrtle-1 41.00 ( 0.00%) 41.00 ( 0.00%) Lat 75.00th-qrtle-1 42.00 ( 0.00%) 42.00 ( 0.00%) Lat 90.00th-qrtle-1 44.00 ( 0.00%) 43.00 ( 2.27%) Lat 95.00th-qrtle-1 53.00 ( 0.00%) 45.00 ( 15.09%) Lat 99.00th-qrtle-1 59.00 ( 0.00%) 58.00 ( 1.69%) Lat 99.50th-qrtle-1 60.00 ( 0.00%) 59.00 ( 1.67%) Lat 99.90th-qrtle-1 86.00 ( 0.00%) 61.00 ( 29.07%) Lat 50.00th-qrtle-2 52.00 ( 0.00%) 41.00 ( 21.15%) Lat 75.00th-qrtle-2 57.00 ( 0.00%) 46.00 ( 19.30%) Lat 90.00th-qrtle-2 60.00 ( 0.00%) 53.00 ( 11.67%) Lat 95.00th-qrtle-2 62.00 ( 0.00%) 57.00 ( 8.06%) Lat 99.00th-qrtle-2 73.00 ( 0.00%) 68.00 ( 6.85%) Lat 99.50th-qrtle-2 74.00 ( 0.00%) 71.00 ( 4.05%) Lat 99.90th-qrtle-2 90.00 ( 0.00%) 75.00 ( 16.67%) Lat 50.00th-qrtle-4 57.00 ( 0.00%) 52.00 ( 8.77%) Lat 75.00th-qrtle-4 60.00 ( 0.00%) 58.00 ( 3.33%) Lat 90.00th-qrtle-4 62.00 ( 0.00%) 62.00 ( 0.00%) Lat 95.00th-qrtle-4 65.00 ( 0.00%) 65.00 ( 0.00%) Lat 99.00th-qrtle-4 76.00 ( 0.00%) 75.00 ( 1.32%) Lat 99.50th-qrtle-4 77.00 ( 0.00%) 77.00 ( 0.00%) Lat 99.90th-qrtle-4 87.00 ( 0.00%) 81.00 ( 6.90%) Lat 50.00th-qrtle-8 59.00 ( 0.00%) 57.00 ( 3.39%) Lat 75.00th-qrtle-8 63.00 ( 0.00%) 62.00 ( 1.59%) Lat 90.00th-qrtle-8 66.00 ( 0.00%) 67.00 ( -1.52%) Lat 95.00th-qrtle-8 68.00 ( 0.00%) 70.00 ( -2.94%) Lat 99.00th-qrtle-8 79.00 ( 0.00%) 80.00 ( -1.27%) Lat 99.50th-qrtle-8 80.00 ( 0.00%) 84.00 ( -5.00%) Lat 99.90th-qrtle-8 84.00 ( 0.00%) 90.00 ( -7.14%) Lat 50.00th-qrtle-16 65.00 ( 0.00%) 65.00 ( 0.00%) Lat 75.00th-qrtle-16 77.00 ( 0.00%) 75.00 ( 2.60%) Lat 90.00th-qrtle-16 84.00 ( 0.00%) 83.00 ( 1.19%) Lat 95.00th-qrtle-16 88.00 ( 0.00%) 87.00 ( 1.14%) Lat 99.00th-qrtle-16 97.00 ( 0.00%) 96.00 ( 1.03%) Lat 99.50th-qrtle-16 100.00 ( 0.00%) 104.00 ( -4.00%) Lat 99.90th-qrtle-16 110.00 ( 0.00%) 126.00 ( -14.55%) Lat 50.00th-qrtle-32 70.00 ( 0.00%) 71.00 ( -1.43%) Lat 75.00th-qrtle-32 92.00 ( 0.00%) 94.00 ( -2.17%) Lat 90.00th-qrtle-32 110.00 ( 0.00%) 110.00 ( 0.00%) Lat 95.00th-qrtle-32 121.00 ( 0.00%) 118.00 ( 2.48%) Lat 99.00th-qrtle-32 135.00 ( 0.00%) 137.00 ( -1.48%) Lat 99.50th-qrtle-32 140.00 ( 0.00%) 146.00 ( -4.29%) Lat 99.90th-qrtle-32 150.00 ( 0.00%) 160.00 ( -6.67%) Lat 50.00th-qrtle-39 80.00 ( 0.00%) 71.00 ( 11.25%) Lat 75.00th-qrtle-39 102.00 ( 0.00%) 91.00 ( 10.78%) Lat 90.00th-qrtle-39 118.00 ( 0.00%) 108.00 ( 8.47%) Lat 95.00th-qrtle-39 128.00 ( 0.00%) 117.00 ( 8.59%) Lat 99.00th-qrtle-39 149.00 ( 0.00%) 133.00 ( 10.74%) Lat 99.50th-qrtle-39 160.00 ( 0.00%) 139.00 ( 13.12%) Lat 99.90th-qrtle-39 13808.00 ( 0.00%) 4920.00 ( 64.37%) Despite being nearly identical, it showed a variety of major gains so I'm not convinced that heavy emphasis should be placed on this particular workload in terms of evaluating this particular patch. Further evidence of this is the fact that testing on a UMA machine showed small gains/losses even though the patch should be a no-op on UMA. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20171219085947.13136-2-mgorman@techsingularity.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/fair: Correct obsolete comment about cpufreq_update_util()Joel Fernandes2018-01-101-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the remote cpufreq callback work, the cpufreq_update_util() call can happen from remote CPUs. The comment about local CPUs is thus obsolete. Update it accordingly. Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Android Kernel <kernel-team@android.com> Cc: Atish Patra <atish.patra@oracle.com> Cc: Chris Redpath <Chris.Redpath@arm.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: EAS Dev <eas-dev@lists.linaro.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Josef Bacik <jbacik@fb.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten Ramussen <morten.rasmussen@arm.com> Cc: Patrick Bellasi <patrick.bellasi@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Rohit Jain <rohit.k.jain@oracle.com> Cc: Saravana Kannan <skannan@quicinc.com> Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: Steve Muckle <smuckle@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vikram Mulukutla <markivx@codeaurora.org> Cc: Vincent Guittot <vincent.guittot@linaro.org> Link: http://lkml.kernel.org/r/20171215153944.220146-2-joelaf@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/fair: Remove impossible condition from find_idlest_group_cpu()Joel Fernandes2018-01-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | find_idlest_group_cpu() goes through CPUs of a group previous selected by find_idlest_group(). find_idlest_group() returns NULL if the local group is the selected one and doesn't execute find_idlest_group_cpu if the group to which 'cpu' belongs to is chosen. So we're always guaranteed to call find_idlest_group_cpu() with a group to which 'cpu' is non-local. This makes one of the conditions in find_idlest_group_cpu() an impossible one, which we can get rid off. Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Brendan Jackman <brendan.jackman@arm.com> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Cc: Android Kernel <kernel-team@android.com> Cc: Atish Patra <atish.patra@oracle.com> Cc: Chris Redpath <Chris.Redpath@arm.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: EAS Dev <eas-dev@lists.linaro.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Josef Bacik <jbacik@fb.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten Ramussen <morten.rasmussen@arm.com> Cc: Patrick Bellasi <patrick.bellasi@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Rohit Jain <rohit.k.jain@oracle.com> Cc: Saravana Kannan <skannan@quicinc.com> Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: Steve Muckle <smuckle@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vikram Mulukutla <markivx@codeaurora.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: http://lkml.kernel.org/r/20171215153944.220146-3-joelaf@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/cpufreq: Don't pass flags to sugov_set_iowait_boost()Viresh Kumar2018-01-101-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are already passing sg_cpu as argument to sugov_set_iowait_boost() helper and the same can be used to retrieve the flags value. Get rid of the redundant argument. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael Wysocki <rjw@rjwysocki.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: dietmar.eggemann@arm.com Cc: joelaf@google.com Cc: juri.lelli@redhat.com Cc: morten.rasmussen@arm.com Cc: tkjos@android.com Link: http://lkml.kernel.org/r/4ec5562b1a87e146ebab11fb5dde1ca9c763a7fb.1513158452.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/cpufreq: Initialize sg_cpu->flags to 0Viresh Kumar2018-01-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Initializing sg_cpu->flags to SCHED_CPUFREQ_RT has no obvious benefit. The flags field wouldn't be used until the utilization update handler is called for the first time, and once that is called we will overwrite flags anyway. Initialize it to 0. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael Wysocki <rjw@rjwysocki.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: dietmar.eggemann@arm.com Cc: joelaf@google.com Cc: morten.rasmussen@arm.com Cc: tkjos@android.com Link: http://lkml.kernel.org/r/763feda6424ced8486b25a0c52979634e6104478.1513158452.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/fair: Consider RT/IRQ pressure in capacity_spare_wake()Joel Fernandes2018-01-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | capacity_spare_wake() in the slow path influences choice of idlest groups, as we search for groups with maximum spare capacity. In scenarios where RT pressure is high, a sub optimal group can be chosen and hurt performance of the task being woken up. Fix this by using capacity_of() instead of capacity_orig_of() in capacity_spare_wake(). Tests results from improvements with this change are below. More tests were also done by myself and Matt Fleming to ensure no degradation in different benchmarks. 1) Rohit ran barrier.c test (details below) with following improvements: ------------------------------------------------------------------------ This was Rohit's original use case for a patch he posted at [1] however from his recent tests he showed my patch can replace his slow path changes [1] and there's no need to selectively scan/skip CPUs in find_idlest_group_cpu in the slow path to get the improvement he sees. barrier.c (open_mp code) as a micro-benchmark. It does a number of iterations and barrier sync at the end of each for loop. Here barrier,c is running in along with ping on CPU 0 and 1 as: 'ping -l 10000 -q -s 10 -f hostX' barrier.c can be found at: http://www.spinics.net/lists/kernel/msg2506955.html Following are the results for the iterations per second with this micro-benchmark (higher is better), on a 44 core, 2 socket 88 Threads Intel x86 machine: +--------+------------------+---------------------------+ |Threads | Without patch | With patch | | | | | +--------+--------+---------+-----------------+---------+ | | Mean | Std Dev | Mean | Std Dev | +--------+--------+---------+-----------------+---------+ |1 | 539.36 | 60.16 | 572.54 (+6.15%) | 40.95 | |2 | 481.01 | 19.32 | 530.64 (+10.32%)| 56.16 | |4 | 474.78 | 22.28 | 479.46 (+0.99%) | 18.89 | |8 | 450.06 | 24.91 | 447.82 (-0.50%) | 12.36 | |16 | 436.99 | 22.57 | 441.88 (+1.12%) | 7.39 | |32 | 388.28 | 55.59 | 429.4 (+10.59%)| 31.14 | |64 | 314.62 | 6.33 | 311.81 (-0.89%) | 11.99 | +--------+--------+---------+-----------------+---------+ 2) ping+hackbench test on bare-metal sever (by Rohit) ----------------------------------------------------- Here hackbench is running in threaded mode along with, running ping on CPU 0 and 1 as: 'ping -l 10000 -q -s 10 -f hostX' This test is running on 2 socket, 20 core and 40 threads Intel x86 machine: Number of loops is 10000 and runtime is in seconds (Lower is better). +--------------+-----------------+--------------------------+ |Task Groups | Without patch | With patch | | +-------+---------+----------------+---------+ |(Groups of 40)| Mean | Std Dev | Mean | Std Dev | +--------------+-------+---------+----------------+---------+ |1 | 0.851 | 0.007 | 0.828 (+2.77%)| 0.032 | |2 | 1.083 | 0.203 | 1.087 (-0.37%)| 0.246 | |4 | 1.601 | 0.051 | 1.611 (-0.62%)| 0.055 | |8 | 2.837 | 0.060 | 2.827 (+0.35%)| 0.031 | |16 | 5.139 | 0.133 | 5.107 (+0.63%)| 0.085 | |25 | 7.569 | 0.142 | 7.503 (+0.88%)| 0.143 | +--------------+-------+---------+----------------+---------+ [1] https://patchwork.kernel.org/patch/9991635/ Matt Fleming also ran several different hackbench tests and cyclic test to santiy-check that the patch doesn't harm other usecases. Tested-by: Matt Fleming <matt@codeblueprint.co.uk> Tested-by: Rohit Jain <rohit.k.jain@oracle.com> Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Atish Patra <atish.patra@oracle.com> Cc: Brendan Jackman <brendan.jackman@arm.com> Cc: Chris Redpath <Chris.Redpath@arm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten Ramussen <morten.rasmussen@arm.com> Cc: Patrick Bellasi <patrick.bellasi@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Saravana Kannan <skannan@quicinc.com> Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: Steve Muckle <smuckle@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vikram Mulukutla <markivx@codeaurora.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: http://lkml.kernel.org/r/20171214212158.188190-1-joelaf@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/fair: Use 'unsigned long' for utilization, consistentlyPatrick Bellasi2018-01-101-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Utilization and capacity are tracked as 'unsigned long', however some functions using them return an 'int' which is ultimately assigned back to 'unsigned long' variables. Since there is not scope on using a different and signed type, consolidate the signature of functions returning utilization to always use the native type. This change improves code consistency, and it also benefits code paths where utilizations should be clamped by avoiding further type conversions or ugly type casts. Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Chris Redpath <chris.redpath@arm.com> Reviewed-by: Brendan Jackman <brendan.jackman@arm.com> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Todd Kjos <tkjos@android.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: http://lkml.kernel.org/r/20171205171018.9203-2-patrick.bellasi@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * sched/core: Rework and clarify prepare_lock_switch()rodrigosiqueira2018-01-102-45/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The prepare_lock_switch() function has an unused parameter, and also the function name was not descriptive. To improve readability and remove the extra parameter, do the following changes: * Move prepare_lock_switch() from kernel/sched/sched.h to kernel/sched/core.c, rename it to prepare_task(), and remove the unused parameter. * Split the smp_store_release() out from finish_lock_switch() to a function named finish_task. * Comments ajdustments. Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.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/20171215140603.gxe5i2y6fg5ojfpp@smtp.gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * Merge branch 'sched/urgent' into sched/core, to pick up fixesIngo Molnar2018-01-1038-903/+489
| | |\ | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | sched/fair: Remove unused 'curr' parameter from wakeup_granCheng Jian2017-12-081-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The first parameter of wakeup_gran(), 'curr', is unnecessary now. Signed-off-by: Cheng Jian <cj.chengjian@huawei.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: huawei.libin@huawei.com Cc: xiexiuqi@huawei.com Link: http://lkml.kernel.org/r/1512653443-179848-1-git-send-email-cj.chengjian@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | Merge branch 'perf-core-for-linus' of ↵Linus Torvalds2018-01-303-34/+39
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "Kernel side changes: - Clean up the x86 instruction decoder (Masami Hiramatsu) - Add new uprobes optimization for PUSH instructions on x86 (Yonghong Song) - Add MSR_IA32_THERM_STATUS to the MSR events (Stephane Eranian) - Fix misc bugs, update documentation, plus various cleanups (Jiri Olsa) There's a large number of tooling side improvements: - Intel-PT/BTS improvements (Adrian Hunter) - Numerous 'perf trace' improvements (Arnaldo Carvalho de Melo) - Introduce an errno code to string facility (Hendrik Brueckner) - Various build system improvements (Jiri Olsa) - Add support for CoreSight trace decoding by making the perf tools use the external openCSD (Mathieu Poirier, Tor Jeremiassen) - Add ARM Statistical Profiling Extensions (SPE) support (Kim Phillips) - libtraceevent updates (Steven Rostedt) - Intel vendor event JSON updates (Andi Kleen) - Introduce 'perf report --mmaps' and 'perf report --tasks' to show info present in 'perf.data' (Jiri Olsa, Arnaldo Carvalho de Melo) - Add infrastructure to record first and last sample time to the perf.data file header, so that when processing all samples in a 'perf record' session, such as when doing build-id processing, or when specifically requesting that that info be recorded, use that in 'perf report --time', that also got support for percent slices in addition to absolute ones. I.e. now it is possible to ask for the samples in the 10%-20% time slice of a perf.data file (Jin Yao) - Allow system wide 'perf stat --per-thread', sorting the result (Jin Yao) E.g.: [root@jouet ~]# perf stat --per-thread --metrics IPC ^C Performance counter stats for 'system wide': make-22229 23,012,094,032 inst_retired.any # 0.8 IPC cc1-22419 692,027,497 inst_retired.any # 0.8 IPC gcc-22418 328,231,855 inst_retired.any # 0.9 IPC cc1-22509 220,853,647 inst_retired.any # 0.8 IPC gcc-22486 199,874,810 inst_retired.any # 1.0 IPC as-22466 177,896,365 inst_retired.any # 0.9 IPC cc1-22465 150,732,374 inst_retired.any # 0.8 IPC gcc-22508 112,555,593 inst_retired.any # 0.9 IPC cc1-22487 108,964,079 inst_retired.any # 0.7 IPC qemu-system-x86-2697 21,330,550 inst_retired.any # 0.3 IPC systemd-journal-551 20,642,951 inst_retired.any # 0.4 IPC docker-containe-17651 9,552,892 inst_retired.any # 0.5 IPC dockerd-current-9809 7,528,586 inst_retired.any # 0.5 IPC make-22153 12,504,194,380 inst_retired.any # 0.8 IPC python2-22429 12,081,290,954 inst_retired.any # 0.8 IPC <SNIP> python2-22429 15,026,328,103 cpu_clk_unhalted.thread cc1-22419 826,660,193 cpu_clk_unhalted.thread gcc-22418 365,321,295 cpu_clk_unhalted.thread cc1-22509 279,169,362 cpu_clk_unhalted.thread gcc-22486 210,156,950 cpu_clk_unhalted.thread <SNIP> 5.638075538 seconds time elapsed [root@jouet ~]# - Improve shell auto-completion of perf events (Jin Yao) - 'perf probe' improvements (Masami Hiramatsu) - Improve PMU infrastructure to support amp64's ThunderX2 implementation defined core events (Ganapatrao Kulkarni) - Various annotation related improvements and fixes (Thomas Richter) - Clarify usage of 'overwrite' and 'backward' in the evlist/mmap code, removing the 'overwrite' parameter from several functions as it was always used it as 'false' (Wang Nan) - Fix/improve 'perf record' reverse recording support (Wang Nan) - Improve command line options documentation (Sihyeon Jang) - Optimize sample parsing for ordering events, where we don't need to parse all the PERF_SAMPLE_ bits, just the ones leading to the timestamp needed to reorder events (Jiri Olsa) - Generalize the annotation code to support other source information besides objdump/DWARF obtained ones, starting with python scripts, that will is slated to be merged soon (Jiri Olsa) - ... and a lot more that I failed to list, see the shortlog and changelog for details" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (262 commits) perf trace beauty flock: Move to separate object file perf evlist: Remove fcntl.h from evlist.h perf trace beauty futex: Beautify FUTEX_BITSET_MATCH_ANY perf trace: Do not print from time delta for interrupted syscall lines perf trace: Add --print-sample perf bpf: Remove misplaced __maybe_unused attribute MAINTAINERS: Adding entry for CoreSight trace decoding perf tools: Add mechanic to synthesise CoreSight trace packets perf tools: Add full support for CoreSight trace decoding pert tools: Add queue management functionality perf tools: Add functionality to communicate with the openCSD decoder perf tools: Add support for decoding CoreSight trace data perf tools: Add decoder mechanic to support dumping trace data perf tools: Add processing of coresight metadata perf tools: Add initial entry point for decoder CoreSight traces perf tools: Integrating the CoreSight decoding library perf vendor events intel: Update IvyTown files to V20 perf vendor events intel: Update IvyBridge files to V20 perf vendor events intel: Update BroadwellDE events to V7 perf vendor events intel: Update SkylakeX events to V1.06 ...
| | * \ \ Merge branch 'perf/urgent' into perf/core, to pick up fixesIngo Molnar2018-01-178-27/+154
| | |\ \ \ | | | | | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | perf: Return empty callchain instead of NULLJiri Olsa2018-01-081-18/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It simplifies the code a bit, because we dump the callchain Link: http://lkml.kernel.org/n/tip-uqp7qd6aif47g39glnbu95yl@git.kernel.org even if it's empty. With 'empty' callchain we can remove all the NULL-checking code paths. Original-patch-from: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/20180107160356.28203-7-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | | perf: Make perf_callchain function staticJiri Olsa2018-01-083-19/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | And move it to core.c, because there's no caller of this function other than the one in core.c Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180107160356.28203-6-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | | perf: Allocate context task_ctx_data for child eventJiri Olsa2018-01-081-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we use perf_event_context::task_ctx_data to save and restore the LBR status when the task is scheduled out and in. We don't allocate it for child contexts, which results in shorter task's LBR stack, because we don't save the history from previous run and start over every time we schedule the task in. I made a test to generate samples with LBR call stack and got higher numbers on bigger chain depths: before: after: LBR call chain: nr: 1 60561 498127 LBR call chain: nr: 2 0 0 LBR call chain: nr: 3 107030 2172 LBR call chain: nr: 4 466685 62758 LBR call chain: nr: 5 2307319 878046 LBR call chain: nr: 6 48713 495218 LBR call chain: nr: 7 1040 4551 LBR call chain: nr: 8 481 172 LBR call chain: nr: 9 878 120 LBR call chain: nr: 10 2377 6698 LBR call chain: nr: 11 28830 151487 LBR call chain: nr: 12 29347 339867 LBR call chain: nr: 13 4 22 LBR call chain: nr: 14 3 53 Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Fixes: 4af57ef28c2c ("perf: Add pmu specific data for perf task context") Link: http://lkml.kernel.org/r/20180107160356.28203-4-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | | Merge branch 'locking-core-for-linus' of ↵Linus Torvalds2018-01-301-42/+47
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "The main changes relate to making lock_is_held() et al (and external wrappers of them) work on const data types - this requires const propagation through the depths of lockdep. This removes a number of ugly type hacks the external helpers used" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep: Convert some users to const lockdep: Make lockdep checking constant lockdep: Assign lock keys on registration
| | * | | | | lockdep: Make lockdep checking constantMatthew Wilcox2018-01-181-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are several places in the kernel which would like to pass a const pointer to lockdep_is_held(). Constify the entire path so nobody has to trick the compiler. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "David S. Miller" <davem@davemloft.net> Link: https://lkml.kernel.org/r/20180117151414.23686-3-willy@infradead.org
| | * | | | | lockdep: Assign lock keys on registrationMatthew Wilcox2018-01-181-36/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lockdep is assigning lock keys when a lock was looked up. This is unnecessary; if the lock has never been registered then it is known that it is not locked. It also complicates the calling convention. Switch to assigning the lock key in register_lock_class(). Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "David S. Miller" <davem@davemloft.net> Link: https://lkml.kernel.org/r/20180117151414.23686-2-willy@infradead.org
| * | | | | | Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds2018-01-3018-418/+311
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The main RCU changes in this cycle were: - Updates to use cond_resched() instead of cond_resched_rcu_qs() where feasible (currently everywhere except in kernel/rcu and in kernel/torture.c). Also a couple of fixes to avoid sending IPIs to offline CPUs. - Updates to simplify RCU's dyntick-idle handling. - Updates to remove almost all uses of smp_read_barrier_depends() and read_barrier_depends(). - Torture-test updates. - Miscellaneous fixes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits) torture: Save a line in stutter_wait(): while -> for torture: Eliminate torture_runnable and perf_runnable torture: Make stutter less vulnerable to compilers and races locking/locktorture: Fix num reader/writer corner cases locking/locktorture: Fix rwsem reader_delay torture: Place all torture-test modules in one MAINTAINERS group rcutorture/kvm-build.sh: Skip build directory check rcutorture: Simplify functions.sh include path rcutorture: Simplify logging rcutorture/kvm-recheck-*: Improve result directory readability check rcutorture/kvm.sh: Support execution from any directory rcutorture/kvm.sh: Use consistent help text for --qemu-args rcutorture/kvm.sh: Remove unused variable, `alldone` rcutorture: Remove unused script, config2frag.sh rcutorture/configinit: Fix build directory error message rcutorture: Preempt RCU-preempt readers more vigorously torture: Reduce #ifdefs for preempt_schedule() rcu: Remove have_rcu_nocb_mask from tree_plugin.h rcu: Add comment giving debug strategy for double call_rcu() tracing, rcu: Hide trace event rcu_nocb_wake when not used ...
| | * \ \ \ \ \ Merge branch 'for-mingo' of ↵Ingo Molnar2018-01-0318-418/+311
| | |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU updates from Paul E. McKenney: - Updates to use cond_resched() instead of cond_resched_rcu_qs() where feasible (currently everywhere except in kernel/rcu and in kernel/torture.c). Also a couple of fixes to avoid sending IPIs to offline CPUs. - Updates to simplify RCU's dyntick-idle handling. - Updates to remove almost all uses of smp_read_barrier_depends() and read_barrier_depends(). - Miscellaneous fixes. - Torture-test updates. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | | | \ \ \ \ \
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| | | *-----. \ \ \ \ \ Merge branches 'cond_resched.2017.12.04a', 'dyntick.2017.11.28a', ↵Paul E. McKenney2017-12-1113-413/+305
| | | |\ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'fixes.2017.12.11a', 'srbd.2017.12.05a' and 'torture.2017.12.11a' into HEAD cond_resched.2017.12.04a: Convert cond_resched_rcu_qs() to cond_resched() dyntick.2017.11.28a: Make RCU dynticks handle interrupts from NMI fixes.2017.12.11a: Miscellaneous fixes srbd.2017.12.05a: Remove now-redundant smp_read_barrier_depends() torture.2017.12.11a: Torture-testing update
| | | | | | | * | | | | | torture: Save a line in stutter_wait(): while -> forPaul E. McKenney2017-12-111-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | | | * | | | | | torture: Eliminate torture_runnable and perf_runnablePaul E. McKenney2017-12-114-19/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The purpose of torture_runnable is to allow rcutorture and locktorture to be started and stopped via sysfs when they are built into the kernel (as in not compiled as loadable modules). However, the 0444 permissions for both instances of torture_runnable prevent this use case from ever being put into practice. Given that there have been no complaints about this deficiency, it is reasonable to conclude that no one actually makes use of this sysfs capability. The perf_runnable module parameter for rcuperf is in the same situation. This commit therefore removes both torture_runnable instances as well as perf_runnable. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | | | * | | | | | torture: Make stutter less vulnerable to compilers and racesPaul E. McKenney2017-12-111-16/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The stutter_wait() function repeatedly fetched stutter_pause_test, and should really just fetch it once on each pass. The races should be harmless, but why have the races? Also, the whole point of the value "2" for stutter_pause_test is to get everyone to start at very nearly the same time, but the value "2" was the first jiffy of the stutter rather than the last jiffy of the stutter. This commit rearranges the code to be more sensible. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | | | * | | | | | locking/locktorture: Fix num reader/writer corner casesDavidlohr Bueso2017-12-111-32/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Things can explode for locktorture if the user does combinations of nwriters_stress=0 nreaders_stress=0. Fix this by not assuming we always want to torture writer threads. Reported-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Jeremy Linton <jeremy.linton@arm.com> Tested-by: Jeremy Linton <jeremy.linton@arm.com>
| | | | | | | * | | | | | locking/locktorture: Fix rwsem reader_delayDavidlohr Bueso2017-12-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We should account for nreader threads, not writers in this callback. Could even trigger a div by 0 if the user explicitly disables writers. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | | | * | | | | | rcutorture: Preempt RCU-preempt readers more vigorouslyPaul E. McKenney2017-12-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit attempts to make a very rare rcutorture failure happen more often by increasing the fraction of RCU-preempt read-side critical sections that are preempted. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | | | * | | | | | torture: Reduce #ifdefs for preempt_schedule()Paul E. McKenney2017-12-112-21/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds a torture_preempt_schedule() that is nothingness in !PREEMPT builds and is preempt_schedule() otherwise. Then torture_preempt_schedule() is used to eliminate several ugly #ifdefs, both in rcutorture and in locktorture. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | | | * | | | | | torture: Suppress CPU stall warnings during shutdown ftrace dumpPaul E. McKenney2017-11-281-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The torture_shutdown() function directly invokes ftrace_dump(), which can result in RCU CPU stall warnings when the ftrace buffer is large, which it usually is. This commit therefore invoks rcu_ftrace_dump() in place of ftrace_dump(), suppressing RCU CPU stall warnings during this time. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | | * | | | | | | tracepoint: Remove smp_read_barrier_depends() from commentPaul E. McKenney2017-12-041-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The comment in tracepoint_add_func() mentions smp_read_barrier_depends(), whose use should be quite restricted. This commit updates the comment to instead mention the smp_store_release() and rcu_dereference_sched() that the current code actually uses. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
| | | | | | * | | | | | | locking: Remove smp_read_barrier_depends() from queued_spin_lock_slowpath()Paul E. McKenney2017-12-041-7/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Queued spinlocks are not used by DEC Alpha, and furthermore operations such as READ_ONCE() and release/relaxed RMW atomics are being changed to imply smp_read_barrier_depends(). This commit therefore removes the now-redundant smp_read_barrier_depends() from queued_spin_lock_slowpath(), and adjusts the comments accordingly. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com>
| | | | | | * | | | | | | uprobes: Remove now-redundant smp_read_barrier_depends()Paul E. McKenney2017-12-041-6/+6
| | | | | | |/ / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that READ_ONCE() implies smp_read_barrier_depends(), the get_xol_area() and get_trampoline_vaddr() no longer need their smp_read_barrier_depends() calls, which this commit removes. While we are here, convert the corresponding smp_wmb() to an smp_store_release(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
| | | | | * | | | | | | rcu: Remove have_rcu_nocb_mask from tree_plugin.hRakib Mullick2017-12-111-7/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently have_rcu_nocb_mask is used to avoid double allocation of rcu_nocb_mask during boot up. Due to different representation of cpumask_var_t on different kernel config CPUMASK=y(or n) it was okay. But now we have a helper cpumask_available(), which can be utilized to check whether rcu_nocb_mask has been allocated or not without using a variable. Removing the variable also reduces vmlinux size. Unpatched version: text data bss dec hex filename 13050393 7852470 14543408 35446271 21cddff vmlinux Patched version: text data bss dec hex filename 13050390 7852438 14543408 35446236 21cdddc vmlinux Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | * | | | | | | rcu: Add comment giving debug strategy for double call_rcu()Paul E. McKenney2017-12-111-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following statement has for some reason proven non-intuitive: WARN_ON_ONCE(rcu_segcblist_empty(&rdp->cblist) != (count == 0)); This commit therefore adds a comment that states that this warning usually triggers in response to a double call_rcu(), which is sort of like a double free. The comment also suggests building with CONFIG_DEBUG_OBJECTS_RCU_HEAD=y to track down the double call_rcu(). Reported-by: David Howells <dhowells@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | * | | | | | | srcu: Prohibit call_srcu() use under raw spinlocksPaul E. McKenney2017-11-281-41/+68
| | | | | |/ / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Invoking queue_delayed_work() while holding a raw spinlock is forbidden in -rt kernels, which is exactly what __call_srcu() does, indirectly via srcu_funnel_gp_start(). This commit therefore downgrades Tree SRCU's locking from raw to non-raw spinlocks, which works because call_srcu() is not ever called while holding a raw spinlock. Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | * | | | | | | rcu: Simplify rcu_eqs_{enter,exit}() non-idle task debug codePaul E. McKenney2017-11-281-22/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The code that checks for non-idle non-nohz_idle-usermode tasks invoking rcu_eqs_enter() and rcu_eqs_exit() prints a considerable quantity of helpful information. However, these checks fire rarely, so the extra complexity is no longer worth it. This commit therefore replaces this debug code with simple WARN_ON_ONCE() statements. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | * | | | | | | rcu: Fold rcu_eqs_exit_common() into rcu_eqs_exit()Paul E. McKenney2017-11-281-32/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is now only one call to rcu_eqs_exit_common() and there is no other reason to keep it separate. This commit therefore inlines it into its sole call site, saving a few lines of code in the process. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | * | | | | | | rcu: Fold rcu_eqs_enter_common() into rcu_eqs_enter()Paul E. McKenney2017-11-281-27/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is now only one call to rcu_eqs_enter_common() and there is no other reason to keep it separate. This commit therefore inlines it into its sole call site, saving a few lines of code in the process. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | * | | | | | | rcu: Avoid ->dynticks_nesting store tearingPaul E. McKenney2017-11-281-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Although ->dynticks_nesting is updated only by process level, it is accessed from hardirq to check for interrupt-from-idle quiescent states. Store tearing is thus possible, so this commit applies WRITE_ONCE() to ->dynticks_nesting stores. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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