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2018-04-03Merge branch 'syscalls-next' of ↵Linus Torvalds1-2/+6
git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux Pull removal of in-kernel calls to syscalls from Dominik Brodowski: "System calls are interaction points between userspace and the kernel. Therefore, system call functions such as sys_xyzzy() or compat_sys_xyzzy() should only be called from userspace via the syscall table, but not from elsewhere in the kernel. At least on 64-bit x86, it will likely be a hard requirement from v4.17 onwards to not call system call functions in the kernel: It is better to use use a different calling convention for system calls there, where struct pt_regs is decoded on-the-fly in a syscall wrapper which then hands processing over to the actual syscall function. This means that only those parameters which are actually needed for a specific syscall are passed on during syscall entry, instead of filling in six CPU registers with random user space content all the time (which may cause serious trouble down the call chain). Those x86-specific patches will be pushed through the x86 tree in the near future. Moreover, rules on how data may be accessed may differ between kernel data and user data. This is another reason why calling sys_xyzzy() is generally a bad idea, and -- at most -- acceptable in arch-specific code. This patchset removes all in-kernel calls to syscall functions in the kernel with the exception of arch/. On top of this, it cleans up the three places where many syscalls are referenced or prototyped, namely kernel/sys_ni.c, include/linux/syscalls.h and include/linux/compat.h" * 'syscalls-next' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux: (109 commits) bpf: whitelist all syscalls for error injection kernel/sys_ni: remove {sys_,sys_compat} from cond_syscall definitions kernel/sys_ni: sort cond_syscall() entries syscalls/x86: auto-create compat_sys_*() prototypes syscalls: sort syscall prototypes in include/linux/compat.h net: remove compat_sys_*() prototypes from net/compat.h syscalls: sort syscall prototypes in include/linux/syscalls.h kexec: move sys_kexec_load() prototype to syscalls.h x86/sigreturn: use SYSCALL_DEFINE0 x86: fix sys_sigreturn() return type to be long, not unsigned long x86/ioport: add ksys_ioperm() helper; remove in-kernel calls to sys_ioperm() mm: add ksys_readahead() helper; remove in-kernel calls to sys_readahead() mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to sys_mmap_pgoff() mm: add ksys_fadvise64_64() helper; remove in-kernel call to sys_fadvise64_64() fs: add ksys_fallocate() wrapper; remove in-kernel calls to sys_fallocate() fs: add ksys_p{read,write}64() helpers; remove in-kernel calls to syscalls fs: add ksys_truncate() wrapper; remove in-kernel calls to sys_truncate() fs: add ksys_sync_file_range helper(); remove in-kernel calls to syscall kernel: add ksys_setsid() helper; remove in-kernel call to sys_setsid() kernel: add ksys_unshare() helper; remove in-kernel calls to sys_unshare() ...
2018-04-03Merge branch 'sched-wait-for-linus' of ↵Linus Torvalds1-84/+26
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull wait_var_event updates from Ingo Molnar: "This introduces the new wait_var_event() API, which is a more flexible waiting primitive than wait_on_atomic_t(). All wait_on_atomic_t() users are migrated over to the new API and wait_on_atomic_t() is removed. The migration fixes one bug and should result in no functional changes for the other usecases" * 'sched-wait-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/wait: Improve __var_waitqueue() code generation sched/wait: Remove the wait_on_atomic_t() API sched/wait, arch/mips: Fix and convert wait_on_atomic_t() usage to the new wait_var_event() API sched/wait, fs/ocfs2: Convert wait_on_atomic_t() usage to the new wait_var_event() API sched/wait, fs/nfs: Convert wait_on_atomic_t() usage to the new wait_var_event() API sched/wait, fs/fscache: Convert wait_on_atomic_t() usage to the new wait_var_event() API sched/wait, fs/btrfs: Convert wait_on_atomic_t() usage to the new wait_var_event() API sched/wait, fs/afs: Convert wait_on_atomic_t() usage to the new wait_var_event() API sched/wait, drivers/media: Convert wait_on_atomic_t() usage to the new wait_var_event() API sched/wait, drivers/drm: Convert wait_on_atomic_t() usage to the new wait_var_event() API sched/wait: Introduce wait_var_event()
2018-04-02Merge branch 'sched-core-for-linus' of ↵Linus Torvalds32-1497/+2026
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main scheduler changes in this cycle were: - NUMA balancing improvements (Mel Gorman) - Further load tracking improvements (Patrick Bellasi) - Various NOHZ balancing cleanups and optimizations (Peter Zijlstra) - Improve blocked load handling, in particular we can now reduce and eventually stop periodic load updates on 'very idle' CPUs. (Vincent Guittot) - On isolated CPUs offload the final 1Hz scheduler tick as well, plus related cleanups and reorganization. (Frederic Weisbecker) - Core scheduler code cleanups (Ingo Molnar)" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits) sched/core: Update preempt_notifier_key to modern API sched/cpufreq: Rate limits for SCHED_DEADLINE sched/fair: Update util_est only on util_avg updates sched/cpufreq/schedutil: Use util_est for OPP selection sched/fair: Use util_est in LB and WU paths sched/fair: Add util_est on top of PELT sched/core: Remove TASK_ALL sched/completions: Use bool in try_wait_for_completion() sched/fair: Update blocked load when newly idle sched/fair: Move idle_balance() sched/nohz: Merge CONFIG_NO_HZ_COMMON blocks sched/fair: Move rebalance_domains() sched/nohz: Optimize nohz_idle_balance() sched/fair: Reduce the periodic update duration sched/nohz: Stop NOHZ stats when decayed sched/cpufreq: Provide migration hint sched/nohz: Clean up nohz enter/exit sched/fair: Update blocked load from NEWIDLE sched/fair: Add NOHZ stats balancing sched/fair: Restructure nohz_balance_kick() ...
2018-04-02sched: add do_sched_yield() helper; remove in-kernel call to sched_yield()Dominik Brodowski1-2/+6
Using the sched-internal do_sched_yield() helper allows us to get rid of the sched-internal call to the sys_sched_yield() syscall. This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Ingo Molnar <mingo@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-03-27sched/core: Update preempt_notifier_key to modern APIDavidlohr Bueso1-6/+6
No changes in refcount semantics, use DEFINE_STATIC_KEY_FALSE() for initialization and replace: static_key_slow_inc|dec() => static_branch_inc|dec() static_key_false() => static_branch_unlikely() Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Link: http://lkml.kernel.org/r/20180326210929.5244-4-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-25Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds1-12/+17
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Two sched debug output related fixes: a console output fix and formatting fixes" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/debug: Adjust newlines for better alignment sched/debug: Fix per-task line continuation for console output
2018-03-24sched/cpufreq: Rate limits for SCHED_DEADLINEClaudio Scordino1-0/+14
When the SCHED_DEADLINE scheduling class increases the CPU utilization, it should not wait for the rate limit, otherwise it may miss some deadline. Tests using rt-app on Exynos5422 with up to 10 SCHED_DEADLINE tasks have shown reductions of even 10% of deadline misses with a negligible increase of energy consumption (measured through Baylibre Cape). Signed-off-by: Claudio Scordino <claudio@evidence.eu.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: linux-pm@vger.kernel.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Patrick Bellasi <patrick.bellasi@arm.com> Cc: Todd Kjos <tkjos@android.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Link: https://lkml.kernel.org/r/1520937340-2755-1-git-send-email-claudio@evidence.eu.com
2018-03-20sched/debug: Adjust newlines for better alignmentJoe Lawrence1-11/+16
Scheduler debug stats include newlines that display out of alignment when prefixed by timestamps. For example, the dmesg utility: % echo t > /proc/sysrq-trigger % dmesg ... [ 83.124251] runnable tasks: S task PID tree-key switches prio wait-time sum-exec sum-sleep ----------------------------------------------------------------------------------------------------------- At the same time, some syslog utilities (like rsyslog by default) don't like the additional newlines control characters, saving lines like this to /var/log/messages: Mar 16 16:02:29 localhost kernel: #012runnable tasks:#012 S task PID tree-key ... ^^^^ ^^^^ Clean these up by moving newline characters to their own SEQ_printf invocation. This leaves the /proc/sched_debug unchanged, but brings the entire output into alignment when prefixed: % echo t > /proc/sysrq-trigger % dmesg ... [ 62.410368] runnable tasks: [ 62.410368] S task PID tree-key switches prio wait-time sum-exec sum-sleep [ 62.410369] ----------------------------------------------------------------------------------------------------------- [ 62.410369] I kworker/u12:0 5 1932.215593 332 120 0.000000 3.621252 0.000000 0 0 / and no escaped control characters from rsyslog in /var/log/messages: Mar 16 16:15:06 localhost kernel: runnable tasks: Mar 16 16:15:06 localhost kernel: S task PID tree-key ... Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1521484555-8620-3-git-send-email-joe.lawrence@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20sched/debug: Fix per-task line continuation for console outputJoe Lawrence1-1/+1
When the SEQ_printf() macro prints to the console, it runs a simple printk() without KERN_CONT "continued" line printing. The result of this is oddly wrapped task info, for example: % echo t > /proc/sysrq-trigger % dmesg ... runnable tasks: ... [ 29.608611] I [ 29.608613] rcu_sched 8 3252.013846 4087 120 [ 29.608614] 0.000000 29.090111 0.000000 [ 29.608615] 0 0 [ 29.608616] / Modify SEQ_printf to use pr_cont() for expected one-line results: % echo t > /proc/sysrq-trigger % dmesg ... runnable tasks: ... [ 106.716329] S cpuhp/5 37 2006.315026 14 120 0.000000 0.496893 0.000000 0 0 / Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1521484555-8620-2-git-send-email-joe.lawrence@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20sched/wait: Improve __var_waitqueue() code generationPeter Zijlstra1-6/+1
Since we fixed hash_64() to not suck there is no need to play games to attempt to improve the hash value on 64-bit. Also, since we don't use the bit value for the variables, use hash_ptr() directly. No change in functionality. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: George Spelvin <linux@sciencehorizons.net> 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>
2018-03-20sched/wait: Remove the wait_on_atomic_t() APIPeter Zijlstra1-101/+0
There are no users left (everyone got converted to wait_var_event()), remove it. 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>
2018-03-20sched/wait: Introduce wait_var_event()Peter Zijlstra1-0/+48
As a replacement for the wait_on_atomic_t() API provide the wait_var_event() API. The wait_var_event() API is based on the very same hashed-waitqueue idea, but doesn't care about the type (atomic_t) or the specific condition (atomic_read() == 0). IOW. it's much more widely applicable/flexible. It shares all the benefits/disadvantages of a hashed-waitqueue approach with the existing wait_on_atomic_t/wait_on_bit() APIs. The API is modeled after the existing wait_event() API, but instead of taking a wait_queue_head, it takes an address. This addresses is hashed to obtain a wait_queue_head from the bit_wait_table. Similar to the wait_event() API, it takes a condition expression as second argument and will wait until this expression becomes true. The following are (mostly) identical replacements: wait_on_atomic_t(&my_atomic, atomic_t_wait, TASK_UNINTERRUPTIBLE); wake_up_atomic_t(&my_atomic); wait_var_event(&my_atomic, !atomic_read(&my_atomic)); wake_up_var(&my_atomic); The only difference is that wake_up_var() is an unconditional wakeup and doesn't check the previously hard-coded (atomic_read() == 0) condition here. This is of little concequence, since most callers are already conditional on atomic_dec_and_test() and the ones that are not, are trivial to make so. Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David Howells <dhowells@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> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20sched/fair: Update util_est only on util_avg updatesPatrick Bellasi2-5/+39
The estimated utilization of a task is currently updated every time the task is dequeued. However, to keep overheads under control, PELT signals are effectively updated at maximum once every 1ms. Thus, for really short running tasks, it can happen that their util_avg value has not been updates since their last enqueue. If such tasks are also frequently running tasks (e.g. the kind of workload generated by hackbench) it can also happen that their util_avg is updated only every few activations. This means that updating util_est at every dequeue potentially introduces not necessary overheads and it's also conceptually wrong if the util_avg signal has never been updated during a task activation. Let's introduce a throttling mechanism on task's util_est updates to sync them with util_avg updates. To make the solution memory efficient, both in terms of space and load/store operations, we encode a synchronization flag into the LSB of util_est.enqueued. This makes util_est an even values only metric, which is still considered good enough for its purpose. The synchronization bit is (re)set by __update_load_avg_se() once the PELT signal of a task has been updated during its last activation. Such a throttling mechanism allows to keep under control util_est overheads in the wakeup hot path, thus making it a suitable mechanism which can be enabled also on high-intensity workload systems. Thus, this now switches on by default the estimation utilization scheduler feature. Suggested-by: Chris Redpath <chris.redpath@arm.com> Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: 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: Steve Muckle <smuckle@google.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/20180309095245.11071-5-patrick.bellasi@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20sched/cpufreq/schedutil: Use util_est for OPP selectionPatrick Bellasi1-1/+8
When schedutil looks at the CPU utilization, the current PELT value for that CPU is returned straight away. In certain scenarios this can have undesired side effects and delays on frequency selection. For example, since the task utilization is decayed at wakeup time, a long sleeping big task newly enqueued does not add immediately a significant contribution to the target CPU. This introduces some latency before schedutil will be able to detect the best frequency required by that task. Moreover, the PELT signal build-up time is a function of the current frequency, because of the scale invariant load tracking support. Thus, starting from a lower frequency, the utilization build-up time will increase even more and further delays the selection of the actual frequency which better serves the task requirements. In order to reduce these kind of latencies, we integrate the usage of the CPU's estimated utilization in the sugov_get_util function. This allows to properly consider the expected utilization of a CPU which, for example, has just got a big task running after a long sleep period. Ultimately this allows to select the best frequency to run a task right after its wake-up. Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> 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: Steve Muckle <smuckle@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Todd Kjos <tkjos@android.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Link: http://lkml.kernel.org/r/20180309095245.11071-4-patrick.bellasi@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20sched/fair: Use util_est in LB and WU pathsPatrick Bellasi1-14/+70
When the scheduler looks at the CPU utilization, the current PELT value for a CPU is returned straight away. In certain scenarios this can have undesired side effects on task placement. For example, since the task utilization is decayed at wakeup time, when a long sleeping big task is enqueued it does not add immediately a significant contribution to the target CPU. As a result we generate a race condition where other tasks can be placed on the same CPU while it is still considered relatively empty. In order to reduce this kind of race conditions, this patch introduces the required support to integrate the usage of the CPU's estimated utilization in the wakeup path, via cpu_util_wake(), as well as in the load-balance path, via cpu_util() which is used by update_sg_lb_stats(). The estimated utilization of a CPU is defined to be the maximum between its PELT's utilization and the sum of the estimated utilization (at previous dequeue time) of all the tasks currently RUNNABLE on that CPU. This allows to properly represent the spare capacity of a CPU which, for example, has just got a big task running since a long sleep period. Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> 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: Steve Muckle <smuckle@google.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/20180309095245.11071-3-patrick.bellasi@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20sched/fair: Add util_est on top of PELTPatrick Bellasi3-6/+125
The util_avg signal computed by PELT is too variable for some use-cases. For example, a big task waking up after a long sleep period will have its utilization almost completely decayed. This introduces some latency before schedutil will be able to pick the best frequency to run a task. The same issue can affect task placement. Indeed, since the task utilization is already decayed at wakeup, when the task is enqueued in a CPU, this can result in a CPU running a big task as being temporarily represented as being almost empty. This leads to a race condition where other tasks can be potentially allocated on a CPU which just started to run a big task which slept for a relatively long period. Moreover, the PELT utilization of a task can be updated every [ms], thus making it a continuously changing value for certain longer running tasks. This means that the instantaneous PELT utilization of a RUNNING task is not really meaningful to properly support scheduler decisions. For all these reasons, a more stable signal can do a better job of representing the expected/estimated utilization of a task/cfs_rq. Such a signal can be easily created on top of PELT by still using it as an estimator which produces values to be aggregated on meaningful events. This patch adds a simple implementation of util_est, a new signal built on top of PELT's util_avg where: util_est(task) = max(task::util_avg, f(task::util_avg@dequeue)) This allows to remember how big a task has been reported by PELT in its previous activations via f(task::util_avg@dequeue), which is the new _task_util_est(struct task_struct*) function added by this patch. If a task should change its behavior and it runs longer in a new activation, after a certain time its util_est will just track the original PELT signal (i.e. task::util_avg). The estimated utilization of cfs_rq is defined only for root ones. That's because the only sensible consumer of this signal are the scheduler and schedutil when looking for the overall CPU utilization due to FAIR tasks. For this reason, the estimated utilization of a root cfs_rq is simply defined as: util_est(cfs_rq) = max(cfs_rq::util_avg, cfs_rq::util_est::enqueued) where: cfs_rq::util_est::enqueued = sum(_task_util_est(task)) for each RUNNABLE task on that root cfs_rq It's worth noting that the estimated utilization is tracked only for objects of interests, specifically: - Tasks: to better support tasks placement decisions - root cfs_rqs: to better support both tasks placement decisions as well as frequencies selection Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> 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: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Steve Muckle <smuckle@google.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/20180309095245.11071-2-patrick.bellasi@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20Merge branch 'linus' into sched/core, to pick up fixesIngo Molnar1-5/+10
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20Merge branch 'for-4.16-fixes' of ↵Linus Torvalds1-5/+10
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: "Two commits to fix the following subtle cgroup2 behavior bugs: - cpu.max was rejecting config when it shouldn't - thread mode enable was allowed when it shouldn't" * 'for-4.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: fix rule checking for threaded mode switching sched, cgroup: Don't reject lower cpu.max on ancestors
2018-03-09sched/completions: Use bool in try_wait_for_completion()gaurav jindal1-3/+3
Since the return type of the function is bool, the internal 'ret' variable should be bool too. Signed-off-by: Gaurav Jindal<gauravjindal1104@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/20180221125407.GA14292@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09sched/fair: Update blocked load when newly idleVincent Guittot1-18/+87
When NEWLY_IDLE load balance is not triggered, we might need to update the blocked load anyway. We can kick an ilb so an idle CPU will take care of updating blocked load or we can try to update them locally before entering idle. In the latter case, we reuse part of the nohz_idle_balance. 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: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: brendan.jackman@arm.com Cc: dietmar.eggemann@arm.com Cc: morten.rasmussen@foss.arm.com Cc: valentin.schneider@arm.com Link: http://lkml.kernel.org/r/1518622006-16089-4-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09sched/fair: Move idle_balance()Peter Zijlstra1-114/+114
We're going to want to call nohz_idle_balance() or parts thereof from idle_balance(). Since we already have a forward declaration of idle_balance() move it down such that it's below nohz_idle_balance() avoiding the need for a forward declaration for that. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> 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>
2018-03-09sched/nohz: Merge CONFIG_NO_HZ_COMMON blocksPeter Zijlstra1-6/+4
Now that we have two back-to-back NO_HZ_COMMON blocks, merge them. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> 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>
2018-03-09sched/fair: Move rebalance_domains()Peter Zijlstra1-118/+118
This pure code movement results in two #ifdef CONFIG_NO_HZ_COMMON sections landing next to each other. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> 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>
2018-03-09sched/nohz: Optimize nohz_idle_balance()Peter Zijlstra1-5/+4
Avoid calling update_blocked_averages() when it does not in fact have any by re-using/extending update_nohz_stats(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> 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>
2018-03-09sched/fair: Reduce the periodic update durationVincent Guittot1-4/+17
Instead of using the cfs_rq_is_decayed() which monitors all *_avg and *_sum, we create a cfs_rq_has_blocked() which only takes care of util_avg and load_avg. We are only interested by these 2 values which are decaying faster than the *_sum so we can stop the periodic update earlier. 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: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: brendan.jackman@arm.com Cc: dietmar.eggemann@arm.com Cc: morten.rasmussen@foss.arm.com Cc: valentin.schneider@arm.com Link: http://lkml.kernel.org/r/1518517879-2280-3-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09sched/nohz: Stop NOHZ stats when decayedVincent Guittot2-20/+97
Stopped the periodic update of blocked load when all idle CPUs have fully decayed. We introduce a new nohz.has_blocked that reflect if some idle CPUs has blocked load that have to be periodiccally updated. nohz.has_blocked is set everytime that a Idle CPU can have blocked load and it is then clear when no more blocked load has been detected during an update. We don't need atomic operation but only to make cure of the right ordering when updating nohz.idle_cpus_mask and nohz.has_blocked. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> 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: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: brendan.jackman@arm.com Cc: dietmar.eggemann@arm.com Cc: morten.rasmussen@foss.arm.com Cc: valentin.schneider@arm.com Link: http://lkml.kernel.org/r/1518517879-2280-2-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09sched/cpufreq: Provide migration hintPeter Zijlstra1-12/+19
It was suggested that a migration hint might be usefull for the CPU-freq governors. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> 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: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09sched/nohz: Clean up nohz enter/exitPeter Zijlstra3-43/+43
The primary observation is that nohz enter/exit is always from the current CPU, therefore NOHZ_TICK_STOPPED does not in fact need to be an atomic. Secondary is that we appear to have 2 nearly identical hooks in the nohz enter code, set_cpu_sd_state_idle() and nohz_balance_enter_idle(). Fold the whole set_cpu_sd_state thing into nohz_balance_{enter,exit}_idle. Removes an atomic op from both enter and exit paths. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.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>
2018-03-09sched/fair: Update blocked load from NEWIDLEPeter Zijlstra3-6/+45
Since we already iterate CPUs looking for work on NEWIDLE, use this iteration to age the blocked load. If the domain for which this is done completely spand the idle set, we can push the ILB based aging forward. Suggested-by: Brendan Jackman <brendan.jackman@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: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09sched/fair: Add NOHZ stats balancingPeter Zijlstra1-12/+19
Teach the idle balancer about the need to update statistics which have a different periodicity from regular balancing. Suggested-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.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>
2018-03-09sched/fair: Restructure nohz_balance_kick()Peter Zijlstra1-107/+111
The current: if (nohz_kick_needed()) nohz_balancer_kick() is pointless complexity, fold them into a single call and avoid the various conditions at the call site. When we introduce multiple different needs to kick the ilb, the above construct also becomes a problem. 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>
2018-03-09sched/fair: Add NOHZ_STATS_KICKPeter Zijlstra3-19/+41
Split the NOHZ idle balancer into doing two separate actions: - update blocked load statistic - actually load-balance Since the latter requires the former, ensure this happens. For now always tag both bits at the same time. Prepares for a future where we can toggle only the STATS bit. Suggested-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: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09sched/core: Convert nohz_flags to atomic_tPeter Zijlstra3-16/+24
Using atomic_t allows us to use the more flexible bitops provided there. Also its smaller. 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>
2018-03-09cpufreq/schedutil: Rewrite CPUFREQ_RT supportPeter Zijlstra2-43/+40
Instead of trying to duplicate scheduler state to track if an RT task is running, directly use the scheduler runqueue state for it. This vastly simplifies things and fixes a number of bugs related to sugov and the scheduler getting out of sync wrt this state. As a consequence we not also update the remove cfs/dl state when iterating the shared mask. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> 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: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09cpufreq/schedutil: Remove unused CPUFREQ_DLPeter Zijlstra1-2/+2
Bitrot... Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> 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: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09sched/fair: Add ';' after label attributesNorbert Manthey1-1/+1
Due to using GCC defines for configuration, some labels might be unused in certain configurations. While adding a __maybe_unused to the label is fine in general, the line has to be terminated with ';'. This is also reflected in the GCC documentation, but GCC parsed the previous variant without an error message. This has been spotted while compiling with goto-cc, the compiler for the CPROVER tool suite. Signed-off-by: Norbert Manthey <nmanthey@amazon.de> Signed-off-by: Michael Tautschnig <tautschn@amazon.co.uk> 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/1519717660-16157-1-git-send-email-nmanthey@amazon.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-04sched/core: Undefine tracepoint creation at the end of core.cIngo Molnar1-0/+2
Make it easier to concatenate all the scheduler .c files for single-module compilation. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-04sched/deadline, rt: Rename queue_push_tasks/queue_pull_task to create ↵Ingo Molnar2-15/+15
separate namespace There are similarly named functions in both of these modules: kernel/sched/deadline.c:static inline void queue_push_tasks(struct rq *rq) kernel/sched/deadline.c:static inline void queue_pull_task(struct rq *rq) kernel/sched/deadline.c:static inline void queue_push_tasks(struct rq *rq) kernel/sched/deadline.c:static inline void queue_pull_task(struct rq *rq) kernel/sched/deadline.c: queue_push_tasks(rq); kernel/sched/deadline.c: queue_pull_task(rq); kernel/sched/deadline.c: queue_push_tasks(rq); kernel/sched/deadline.c: queue_pull_task(rq); kernel/sched/rt.c:static inline void queue_push_tasks(struct rq *rq) kernel/sched/rt.c:static inline void queue_pull_task(struct rq *rq) kernel/sched/rt.c:static inline void queue_push_tasks(struct rq *rq) kernel/sched/rt.c: queue_push_tasks(rq); kernel/sched/rt.c: queue_pull_task(rq); kernel/sched/rt.c: queue_push_tasks(rq); kernel/sched/rt.c: queue_pull_task(rq); ... which makes it harder to grep for them. Prefix them with deadline_ and rt_, respectively. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-04sched/idle: Merge kernel/sched/idle.c and kernel/sched/idle_task.cIngo Molnar3-120/+125
Merge these two small .c modules as they implement two aspects of idle task handling. 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>
2018-03-04sched/headers: Simplify and clean up header usage in the schedulerIngo Molnar28-213/+94
Do the following cleanups and simplifications: - sched/sched.h already includes <asm/paravirt.h>, so no need to include it in sched/core.c again. - order the <linux/sched/*.h> headers alphabetically - add all <linux/sched/*.h> headers to kernel/sched/sched.h - remove all unnecessary includes from the .c files that are already included in kernel/sched/sched.h. Finally, make all scheduler .c files use a single common header: #include "sched.h" ... which now contains a union of the relied upon headers. This makes the various .c files easier to read and easier to handle. 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>
2018-03-03sched: Clean up and harmonize the coding style of the scheduler code baseIngo Molnar28-710/+706
A good number of small style inconsistencies have accumulated in the scheduler core, so do a pass over them to harmonize all these details: - fix speling in comments, - use curly braces for multi-line statements, - remove unnecessary parentheses from integer literals, - capitalize consistently, - remove stray newlines, - add comments where necessary, - remove invalid/unnecessary comments, - align structure definitions and other data types vertically, - add missing newlines for increased readability, - fix vertical tabulation where it's misaligned, - harmonize preprocessor conditional block labeling and vertical alignment, - remove line-breaks where they uglify the code, - add newline after local variable definitions, No change in functionality: md5: 1191fa0a890cfa8132156d2959d7e9e2 built-in.o.before.asm 1191fa0a890cfa8132156d2959d7e9e2 built-in.o.after.asm 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>
2018-03-03sched/deadline: Clean up various coding style detailsMario Leinweber1-1/+4
- Fixed style error: Missing space before the open parenthesis - Fixed style warnings: 2x Missing blank line after declaration One warning left: else after return (I don't feel comfortable fixing that without side effects) Signed-off-by: Mario Leinweber <marioleinweber@web.de> 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 Link: http://lkml.kernel.org/r/20180302182007.28691-1-marioleinweber@web.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21sched/nohz: Remove the 1 Hz tick codeFrederic Weisbecker3-40/+1
Now that the 1Hz tick is offloaded to workqueues, we can safely remove the residual code that used to handle it locally. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1519186649-3242-7-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21sched/isolation: Offload residual 1Hz scheduler tickFrederic Weisbecker8-1/+136
When a CPU runs in full dynticks mode, a 1Hz tick remains in order to keep the scheduler stats alive. However this residual tick is a burden for bare metal tasks that can't stand any interruption at all, or want to minimize them. The usual boot parameters "nohz_full=" or "isolcpus=nohz" will now outsource these scheduler ticks to the global workqueue so that a housekeeping CPU handles those remotely. The sched_class::task_tick() implementations have been audited and look safe to be called remotely as the target runqueue and its current task are passed in parameter and don't seem to be accessed locally. Note that in the case of using isolcpus, it's still up to the user to affine the global workqueues to the housekeeping CPUs through /sys/devices/virtual/workqueue/cpumask or domains isolation "isolcpus=nohz,domain". Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1519186649-3242-6-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21sched/isolation: Isolate workqueues when "nohz_full=" is setFrederic Weisbecker1-1/+2
As we prepare for offloading the residual 1hz scheduler ticks to workqueue, let's affine those to housekeepers so that they don't interrupt the CPUs that don't want to be disturbed. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1519186649-3242-5-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21sched/core: Rename init_rq_hrtick() to hrtick_rq_init()Frederic Weisbecker1-3/+3
Do that rename in order to normalize the hrtick namespace. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1519186649-3242-2-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21sched/numa: Delay retrying placement for automatic NUMA balance after ↵Mel Gorman1-1/+56
wake_affine() If wake_affine() pulls a task to another node for any reason and the node is no longer preferred then temporarily stop automatic NUMA balancing pulling the task back. Otherwise, tasks with a strong waker/wakee relationship may constantly fight automatic NUMA balancing over where a task should be placed. Once again netperf is interesting here. The performance barely changes but automatic NUMA balancing is interesting: Hmean send-64 354.67 ( 0.00%) 352.15 ( -0.71%) Hmean send-128 702.91 ( 0.00%) 693.84 ( -1.29%) Hmean send-256 1350.07 ( 0.00%) 1344.19 ( -0.44%) Hmean send-1024 5124.38 ( 0.00%) 4941.24 ( -3.57%) Hmean send-2048 9687.44 ( 0.00%) 9624.45 ( -0.65%) Hmean send-3312 14577.64 ( 0.00%) 14514.35 ( -0.43%) Hmean send-4096 16393.62 ( 0.00%) 16488.30 ( 0.58%) Hmean send-8192 26877.26 ( 0.00%) 26431.63 ( -1.66%) Hmean send-16384 38683.43 ( 0.00%) 38264.91 ( -1.08%) Hmean recv-64 354.67 ( 0.00%) 352.15 ( -0.71%) Hmean recv-128 702.91 ( 0.00%) 693.84 ( -1.29%) Hmean recv-256 1350.07 ( 0.00%) 1344.19 ( -0.44%) Hmean recv-1024 5124.38 ( 0.00%) 4941.24 ( -3.57%) Hmean recv-2048 9687.43 ( 0.00%) 9624.45 ( -0.65%) Hmean recv-3312 14577.59 ( 0.00%) 14514.35 ( -0.43%) Hmean recv-4096 16393.55 ( 0.00%) 16488.20 ( 0.58%) Hmean recv-8192 26876.96 ( 0.00%) 26431.29 ( -1.66%) Hmean recv-16384 38682.41 ( 0.00%) 38263.94 ( -1.08%) NUMA alloc hit 1465986 1423090 NUMA alloc miss 0 0 NUMA interleave hit 0 0 NUMA alloc local 1465897 1423003 NUMA base PTE updates 1473 1420 NUMA huge PMD updates 0 0 NUMA page range updates 1473 1420 NUMA hint faults 1383 1312 NUMA hint local faults 451 124 NUMA hint local percent 32 9 There is a slight degrading in performance but there are slightly fewer NUMA faults. There is a large drop in the percentage of local faults but the bulk of migrations for netperf are in small shared libraries so it's reflecting the fact that automatic NUMA balancing has backed off. This is a case where despite wake_affine() and automatic NUMA balancing fighting for placement that there is a marginal benefit to rescheduling to local data quickly. However, it should be noted that wake_affine() and automatic NUMA balancing fighting each other constantly is undesirable. However, the benefit in other cases is large. This is the result for NAS with the D class sizing on a 4-socket machine: nas-mpi 4.15.0 4.15.0 sdnuma-v1r23 delayretry-v1r23 Time cg.D 557.00 ( 0.00%) 431.82 ( 22.47%) Time ep.D 77.83 ( 0.00%) 79.01 ( -1.52%) Time is.D 26.46 ( 0.00%) 26.64 ( -0.68%) Time lu.D 727.14 ( 0.00%) 597.94 ( 17.77%) Time mg.D 191.35 ( 0.00%) 146.85 ( 23.26%) 4.15.0 4.15.0 sdnuma-v1r23delayretry-v1r23 User 75665.20 70413.30 System 20321.59 8861.67 Elapsed 766.13 634.92 Minor Faults 16528502 7127941 Major Faults 4553 5068 NUMA alloc local 6963197 6749135 NUMA base PTE updates 366409093 107491434 NUMA huge PMD updates 687556 198880 NUMA page range updates 718437765 209317994 NUMA hint faults 13643410 4601187 NUMA hint local faults 9212593 3063996 NUMA hint local percent 67 66 Note the massive reduction in system CPU usage even though the percentage of local faults is barely affected. There is a massive reduction in the number of PTE updates showing that automatic NUMA balancing has backed off. A critical observation is also that there is a massive reduction in minor faults which is due to far fewer NUMA hinting faults being trapped. There were questions on NAS OMP and how it behaved related to threads being bound to CPUs. First, there are more gains than losses with this patch applied and a reduction in system CPU usage: nas-omp 4.16.0-rc1 4.16.0-rc1 sdnuma-v2r1 delayretry-v2r1 Time bt.D 436.71 ( 0.00%) 430.05 ( 1.53%) Time cg.D 201.02 ( 0.00%) 180.87 ( 10.02%) Time ep.D 32.84 ( 0.00%) 32.68 ( 0.49%) Time is.D 9.63 ( 0.00%) 9.64 ( -0.10%) Time lu.D 331.20 ( 0.00%) 304.80 ( 7.97%) Time mg.D 54.87 ( 0.00%) 52.72 ( 3.92%) Time sp.D 1108.78 ( 0.00%) 917.10 ( 17.29%) Time ua.D 378.81 ( 0.00%) 398.83 ( -5.28%) 4.16.0-rc1 4.16.0-rc1 sdnuma-v2r1delayretry-v2r1 User 305633.08 296751.91 System 451.75 357.80 Elapsed 2595.73 2368.13 However, it does not close the gap between binding and being unbound. There is negligible difference between the performance of the baseline and a patched kernel when threads are bound so it is not presented here: 4.16.0-rc1 4.16.0-rc1 delayretry-bind delayretry-unbound Time bt.D 385.02 ( 0.00%) 430.05 ( -11.70%) Time cg.D 144.02 ( 0.00%) 180.87 ( -25.59%) Time ep.D 32.85 ( 0.00%) 32.68 ( 0.52%) Time is.D 10.52 ( 0.00%) 9.64 ( 8.37%) Time lu.D 285.31 ( 0.00%) 304.80 ( -6.83%) Time mg.D 43.21 ( 0.00%) 52.72 ( -22.01%) Time sp.D 820.24 ( 0.00%) 917.10 ( -11.81%) Time ua.D 337.09 ( 0.00%) 398.83 ( -18.32%) 4.16.0-rc1 4.16.0-rc1 delayretry-binddelayretry-unbound User 277731.25 296751.91 System 261.29 357.80 Elapsed 2100.55 2368.13 Unfortunately, while performance is improved by the patch, there is still quite a long way to go before it's equivalent to hard binding. Other workloads like hackbench, tbench, dbench and schbench are barely affected. dbench shows a mix of gains and losses depending on the machine although in general, the results are more stable. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Giovanni Gherdovich <ggherdovich@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180213133730.24064-7-mgorman@techsingularity.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21sched/fair: Consider SD_NUMA when selecting the most idle group to schedule onMel Gorman1-0/+12
find_idlest_group() compares a local group with each other group to select the one that is most idle. When comparing groups in different NUMA domains, a very slight imbalance is enough to select a remote NUMA node even if the runnable load on both groups is 0 or close to 0. This ignores the cost of remote accesses entirely and is a problem when selecting the CPU for a newly forked task to run on. This is problematic when a forking server is almost guaranteed to run on a remote node incurring numerous remote accesses and potentially causing automatic NUMA balancing to try migrate the task back or migrate the data to another node. Similar weirdness is observed if a basic shell command pipes output to another as each process in the pipeline is likely to start on different nodes and then get adjusted later by wake_affine(). This patch adds imbalance to remote domains when considering whether to select CPUs from remote domains. If the local domain is selected, imbalance will still be used to try select a CPU from a lower scheduler domain's group instead of stacking tasks on the same CPU. A variety of workloads and machines were tested and as expected, there is no difference on UMA. The difference on NUMA can be dramatic. This is a comparison of elapsed times running the git regression test suite. It's fork-intensive with short-lived processes: 4.15.0 4.15.0 noexit-v1r23 sdnuma-v1r23 Elapsed min 1706.06 ( 0.00%) 1435.94 ( 15.83%) Elapsed mean 1709.53 ( 0.00%) 1436.98 ( 15.94%) Elapsed stddev 2.16 ( 0.00%) 1.01 ( 53.38%) Elapsed coeffvar 0.13 ( 0.00%) 0.07 ( 44.54%) Elapsed max 1711.59 ( 0.00%) 1438.01 ( 15.98%) 4.15.0 4.15.0 noexit-v1r23 sdnuma-v1r23 User 5434.12 5188.41 System 4878.77 3467.09 Elapsed 10259.06 8624.21 That shows a considerable reduction in elapsed times. It's important to note that automatic NUMA balancing does not affect this load as processes are too short-lived. There is also a noticable impact on hackbench such as this example using processes and pipes: hackbench-process-pipes 4.15.0 4.15.0 noexit-v1r23 sdnuma-v1r23 Amean 1 1.0973 ( 0.00%) 0.9393 ( 14.40%) Amean 4 1.3427 ( 0.00%) 1.3730 ( -2.26%) Amean 7 1.4233 ( 0.00%) 1.6670 ( -17.12%) Amean 12 3.0250 ( 0.00%) 3.3013 ( -9.13%) Amean 21 9.0860 ( 0.00%) 9.5343 ( -4.93%) Amean 30 14.6547 ( 0.00%) 13.2433 ( 9.63%) Amean 48 22.5447 ( 0.00%) 20.4303 ( 9.38%) Amean 79 29.2010 ( 0.00%) 26.7853 ( 8.27%) Amean 110 36.7443 ( 0.00%) 35.8453 ( 2.45%) Amean 141 45.8533 ( 0.00%) 42.6223 ( 7.05%) Amean 172 55.1317 ( 0.00%) 50.6473 ( 8.13%) Amean 203 64.4420 ( 0.00%) 58.3957 ( 9.38%) Amean 234 73.2293 ( 0.00%) 67.1047 ( 8.36%) Amean 265 80.5220 ( 0.00%) 75.7330 ( 5.95%) Amean 296 88.7567 ( 0.00%) 82.1533 ( 7.44%) It's not a universal win as there are occasions when spreading wide and quickly is a benefit but it's more of a win than it is a loss. For other workloads, there is little difference but netperf is interesting. Without the patch, the server and client starts on different nodes but quickly get migrated due to wake_affine. Hence, the difference is overall performance is marginal but detectable: 4.15.0 4.15.0 noexit-v1r23 sdnuma-v1r23 Hmean send-64 349.09 ( 0.00%) 354.67 ( 1.60%) Hmean send-128 699.16 ( 0.00%) 702.91 ( 0.54%) Hmean send-256 1316.34 ( 0.00%) 1350.07 ( 2.56%) Hmean send-1024 5063.99 ( 0.00%) 5124.38 ( 1.19%) Hmean send-2048 9705.19 ( 0.00%) 9687.44 ( -0.18%) Hmean send-3312 14359.48 ( 0.00%) 14577.64 ( 1.52%) Hmean send-4096 16324.20 ( 0.00%) 16393.62 ( 0.43%) Hmean send-8192 26112.61 ( 0.00%) 26877.26 ( 2.93%) Hmean send-16384 37208.44 ( 0.00%) 38683.43 ( 3.96%) Hmean recv-64 349.09 ( 0.00%) 354.67 ( 1.60%) Hmean recv-128 699.16 ( 0.00%) 702.91 ( 0.54%) Hmean recv-256 1316.34 ( 0.00%) 1350.07 ( 2.56%) Hmean recv-1024 5063.99 ( 0.00%) 5124.38 ( 1.19%) Hmean recv-2048 9705.16 ( 0.00%) 9687.43 ( -0.18%) Hmean recv-3312 14359.42 ( 0.00%) 14577.59 ( 1.52%) Hmean recv-4096 16323.98 ( 0.00%) 16393.55 ( 0.43%) Hmean recv-8192 26111.85 ( 0.00%) 26876.96 ( 2.93%) Hmean recv-16384 37206.99 ( 0.00%) 38682.41 ( 3.97%) However, what is very interesting is how automatic NUMA balancing behaves. Each netperf instance runs long enough for balancing to activate: NUMA base PTE updates 4620 1473 NUMA huge PMD updates 0 0 NUMA page range updates 4620 1473 NUMA hint faults 4301 1383 NUMA hint local faults 1309 451 NUMA hint local percent 30 32 NUMA pages migrated 1335 491 AutoNUMA cost 21% 6% There is an unfortunate number of remote faults although tracing indicated that the vast majority are in shared libraries. However, the tendency to start tasks on the same node if there is capacity means that there were far fewer PTE updates and faults incurred overall. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Giovanni Gherdovich <ggherdovich@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180213133730.24064-6-mgorman@techsingularity.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21sched/fair: Do not migrate due to a sync wakeup on exitPeter Zijlstra1-1/+1
When a task exits, it notifies the parent that it has exited. This is a sync wakeup and the exiting task may pull the parent towards the wakers CPU. For simple workloads like using a shell, it was observed that the shell is pulled across nodes by exiting processes. This is daft as the parent may be long-lived and properly placed. This patch special cases a sync wakeup on exit to avoid pulling tasks across nodes. Testing on a range of workloads and machines showed very little differences in performance although there was a small 3% boost on some machines running a shellscript intensive workload (git regression test suite). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Giovanni Gherdovich <ggherdovich@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180213133730.24064-5-mgorman@techsingularity.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21sched/fair: Do not migrate on wake_affine_weight() if weights are equalMel Gorman1-1/+10
wake_affine_weight() will consider migrating a task to, or near, the current CPU if there is a load imbalance. If the CPUs share LLC then either CPU is valid as a search-for-idle-sibling target and equally appropriate for stacking two tasks on one CPU if an idle sibling is unavailable. If they do not share cache then a cross-node migration potentially impacts locality so while they are equal from a CPU capacity point of view, they are not equal in terms of memory locality. In either case, it's more appropriate to migrate only if there is a difference in their effective load. This patch modifies wake_affine_weight() to only consider migrating a task if there is a load imbalance for normal wakeups but will allow potential stacking if the loads are equal and it's a sync wakeup. For the most part, the different in performance is marginal. For example, on a 4-socket server running netperf UDP_STREAM on localhost the differences are as follows: 4.15.0 4.15.0 16rc0 noequal-v1r23 Hmean send-64 355.47 ( 0.00%) 349.50 ( -1.68%) Hmean send-128 697.98 ( 0.00%) 693.35 ( -0.66%) Hmean send-256 1328.02 ( 0.00%) 1318.77 ( -0.70%) Hmean send-1024 5051.83 ( 0.00%) 5051.11 ( -0.01%) Hmean send-2048 9637.02 ( 0.00%) 9601.34 ( -0.37%) Hmean send-3312 14355.37 ( 0.00%) 14414.51 ( 0.41%) Hmean send-4096 16464.97 ( 0.00%) 16301.37 ( -0.99%) Hmean send-8192 26722.42 ( 0.00%) 26428.95 ( -1.10%) Hmean send-16384 38137.81 ( 0.00%) 38046.11 ( -0.24%) Hmean recv-64 355.47 ( 0.00%) 349.50 ( -1.68%) Hmean recv-128 697.98 ( 0.00%) 693.35 ( -0.66%) Hmean recv-256 1328.02 ( 0.00%) 1318.77 ( -0.70%) Hmean recv-1024 5051.83 ( 0.00%) 5051.11 ( -0.01%) Hmean recv-2048 9636.95 ( 0.00%) 9601.30 ( -0.37%) Hmean recv-3312 14355.32 ( 0.00%) 14414.48 ( 0.41%) Hmean recv-4096 16464.74 ( 0.00%) 16301.16 ( -0.99%) Hmean recv-8192 26721.63 ( 0.00%) 26428.17 ( -1.10%) Hmean recv-16384 38136.00 ( 0.00%) 38044.88 ( -0.24%) Stddev send-64 7.30 ( 0.00%) 4.75 ( 34.96%) Stddev send-128 15.15 ( 0.00%) 22.38 ( -47.66%) Stddev send-256 13.99 ( 0.00%) 19.14 ( -36.81%) Stddev send-1024 105.73 ( 0.00%) 67.38 ( 36.27%) Stddev send-2048 294.57 ( 0.00%) 223.88 ( 24.00%) Stddev send-3312 302.28 ( 0.00%) 271.74 ( 10.10%) Stddev send-4096 195.92 ( 0.00%) 121.10 ( 38.19%) Stddev send-8192 399.71 ( 0.00%) 563.77 ( -41.04%) Stddev send-16384 1163.47 ( 0.00%) 1103.68 ( 5.14%) Stddev recv-64 7.30 ( 0.00%) 4.75 ( 34.96%) Stddev recv-128 15.15 ( 0.00%) 22.38 ( -47.66%) Stddev recv-256 13.99 ( 0.00%) 19.14 ( -36.81%) Stddev recv-1024 105.73 ( 0.00%) 67.38 ( 36.27%) Stddev recv-2048 294.59 ( 0.00%) 223.89 ( 24.00%) Stddev recv-3312 302.24 ( 0.00%) 271.75 ( 10.09%) Stddev recv-4096 196.03 ( 0.00%) 121.14 ( 38.20%) Stddev recv-8192 399.86 ( 0.00%) 563.65 ( -40.96%) Stddev recv-16384 1163.79 ( 0.00%) 1103.86 ( 5.15%) The difference in overall performance is marginal but note that most measurements are less variable. There were similar observations for other netperf comparisons. hackbench with sockets or threads with processes or threads showed minor difference with some reduction of migration. tbench showed only marginal differences that were within the noise. dbench, regardless of filesystem, showed minor differences all of which are within noise. Multiple machines, both UMA and NUMA were tested without any regressions showing up. The biggest risk with a patch like this is affecting wakeup latencies. However, the schbench load from Facebook which is very sensitive to wakeup latency showed a mixed result with mostly improvements in wakeup latency: 4.15.0 4.15.0 16rc0 noequal-v1r23 Lat 50.00th-qrtle-1 38.00 ( 0.00%) 38.00 ( 0.00%) Lat 75.00th-qrtle-1 49.00 ( 0.00%) 41.00 ( 16.33%) Lat 90.00th-qrtle-1 52.00 ( 0.00%) 50.00 ( 3.85%) Lat 95.00th-qrtle-1 54.00 ( 0.00%) 51.00 ( 5.56%) Lat 99.00th-qrtle-1 63.00 ( 0.00%) 60.00 ( 4.76%) Lat 99.50th-qrtle-1 66.00 ( 0.00%) 61.00 ( 7.58%) Lat 99.90th-qrtle-1 78.00 ( 0.00%) 65.00 ( 16.67%) Lat 50.00th-qrtle-2 38.00 ( 0.00%) 38.00 ( 0.00%) Lat 75.00th-qrtle-2 42.00 ( 0.00%) 43.00 ( -2.38%) Lat 90.00th-qrtle-2 46.00 ( 0.00%) 48.00 ( -4.35%) Lat 95.00th-qrtle-2 49.00 ( 0.00%) 50.00 ( -2.04%) Lat 99.00th-qrtle-2 55.00 ( 0.00%) 57.00 ( -3.64%) Lat 99.50th-qrtle-2 58.00 ( 0.00%) 60.00 ( -3.45%) Lat 99.90th-qrtle-2 65.00 ( 0.00%) 68.00 ( -4.62%) Lat 50.00th-qrtle-4 41.00 ( 0.00%) 41.00 ( 0.00%) Lat 75.00th-qrtle-4 45.00 ( 0.00%) 46.00 ( -2.22%) Lat 90.00th-qrtle-4 50.00 ( 0.00%) 50.00 ( 0.00%) Lat 95.00th-qrtle-4 54.00 ( 0.00%) 53.00 ( 1.85%) Lat 99.00th-qrtle-4 61.00 ( 0.00%) 61.00 ( 0.00%) Lat 99.50th-qrtle-4 65.00 ( 0.00%) 64.00 ( 1.54%) Lat 99.90th-qrtle-4 76.00 ( 0.00%) 82.00 ( -7.89%) Lat 50.00th-qrtle-8 48.00 ( 0.00%) 46.00 ( 4.17%) Lat 75.00th-qrtle-8 55.00 ( 0.00%) 54.00 ( 1.82%) Lat 90.00th-qrtle-8 60.00 ( 0.00%) 59.00 ( 1.67%) Lat 95.00th-qrtle-8 63.00 ( 0.00%) 63.00 ( 0.00%) Lat 99.00th-qrtle-8 71.00 ( 0.00%) 69.00 ( 2.82%) Lat 99.50th-qrtle-8 74.00 ( 0.00%) 73.00 ( 1.35%) Lat 99.90th-qrtle-8 98.00 ( 0.00%) 90.00 ( 8.16%) Lat 50.00th-qrtle-16 56.00 ( 0.00%) 55.00 ( 1.79%) Lat 75.00th-qrtle-16 68.00 ( 0.00%) 67.00 ( 1.47%) Lat 90.00th-qrtle-16 77.00 ( 0.00%) 78.00 ( -1.30%) Lat 95.00th-qrtle-16 82.00 ( 0.00%) 84.00 ( -2.44%) Lat 99.00th-qrtle-16 90.00 ( 0.00%) 93.00 ( -3.33%) Lat 99.50th-qrtle-16 93.00 ( 0.00%) 97.00 ( -4.30%) Lat 99.90th-qrtle-16 110.00 ( 0.00%) 110.00 ( 0.00%) Lat 50.00th-qrtle-32 68.00 ( 0.00%) 62.00 ( 8.82%) Lat 75.00th-qrtle-32 90.00 ( 0.00%) 83.00 ( 7.78%) Lat 90.00th-qrtle-32 110.00 ( 0.00%) 100.00 ( 9.09%) Lat 95.00th-qrtle-32 122.00 ( 0.00%) 111.00 ( 9.02%) Lat 99.00th-qrtle-32 145.00 ( 0.00%) 133.00 ( 8.28%) Lat 99.50th-qrtle-32 154.00 ( 0.00%) 143.00 ( 7.14%) Lat 99.90th-qrtle-32 2316.00 ( 0.00%) 515.00 ( 77.76%) Lat 50.00th-qrtle-35 69.00 ( 0.00%) 72.00 ( -4.35%) Lat 75.00th-qrtle-35 92.00 ( 0.00%) 95.00 ( -3.26%) Lat 90.00th-qrtle-35 111.00 ( 0.00%) 114.00 ( -2.70%) Lat 95.00th-qrtle-35 122.00 ( 0.00%) 124.00 ( -1.64%) Lat 99.00th-qrtle-35 142.00 ( 0.00%) 144.00 ( -1.41%) Lat 99.50th-qrtle-35 150.00 ( 0.00%) 154.00 ( -2.67%) Lat 99.90th-qrtle-35 6104.00 ( 0.00%) 5640.00 ( 7.60%) Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Giovanni Gherdovich <ggherdovich@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180213133730.24064-4-mgorman@techsingularity.net Signed-off-by: Ingo Molnar <mingo@kernel.org>