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2017-11-15Merge branch 'for-4.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Cgroup2 cpu controller support is finally merged. - Basic cpu statistics support to allow monitoring by default without the CPU controller enabled. - cgroup2 cpu controller support. - /sys/kernel/cgroup files to help dealing with new / optional features" * 'for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: export list of cgroups v2 features using sysfs cgroup: export list of delegatable control files using sysfs cgroup: mark @cgrp __maybe_unused in cpu_stat_show() MAINTAINERS: relocate cpuset.c cgroup, sched: Move basic cpu stats from cgroup.stat to cpu.stat sched: Implement interface for cgroup unified hierarchy sched: Misc preps for cgroup unified hierarchy interface sched/cputime: Add dummy cputime_adjust() implementation for CONFIG_VIRT_CPU_ACCOUNTING_NATIVE cgroup: statically initialize init_css_set->dfl_cgrp cgroup: Implement cgroup2 basic CPU usage accounting cpuacct: Introduce cgroup_account_cputime[_field]() sched/cputime: Expose cputime_adjust()
2017-11-09sched/core: Optimize sched_feat() for !CONFIG_SCHED_DEBUG buildsPatrick Bellasi
When the kernel is compiled with !CONFIG_SCHED_DEBUG support, we expect that all SCHED_FEAT are turned into compile time constants being propagated to support compiler optimizations. Specifically, we expect that code blocks like this: if (sched_feat(FEATURE_NAME) [&& <other_conditions>]) { /* FEATURE CODE */ } are turned into dead-code in case FEATURE_NAME defaults to FALSE, and thus being removed by the compiler from the finale image. For this mechanism to properly work it's required for the compiler to have full access, from each translation unit, to whatever is the value defined by the sched_feat macro. This macro is defined as: #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) and thus, the compiler can optimize that code only if the value of sysctl_sched_features is visible within each translation unit. Since: 029632fbb ("sched: Make separate sched*.c translation units") the scheduler code has been split into separate translation units however the definition of sysctl_sched_features is part of kernel/sched/core.c while, for all the other scheduler modules, it is visible only via kernel/sched/sched.h as an: extern const_debug unsigned int sysctl_sched_features Unfortunately, an extern reference does not allow the compiler to apply constants propagation. Thus, on !CONFIG_SCHED_DEBUG kernel we still end up with code to load a memory reference and (eventually) doing an unconditional jump of a chunk of code. This mechanism is unavoidable when sched_features can be turned on and off at run-time. However, this is not the case for "production" kernels compiled with !CONFIG_SCHED_DEBUG. In this case, sysctl_sched_features is just a constant value which cannot be changed at run-time and thus memory loads and jumps can be avoided altogether. This patch fixes the case of !CONFIG_SCHED_DEBUG kernel by declaring a local version of the sysctl_sched_features constant for each translation unit. This will ultimately allow the compiler to perform constants propagation and dead-code pruning. Tests have been done, with !CONFIG_SCHED_DEBUG on a v4.14-rc8 with and without the patch, by running 30 iterations of: perf bench sched messaging --pipe --thread --group 4 --loop 50000 on a 40 cores Intel(R) Xeon(R) CPU E5-2690 v2 @ 3.00GHz using the powersave governor to rule out variations due to frequency scaling. Statistics on the reported completion time: count mean std min 99% max v4.14-rc8 30.0 15.7831 0.176032 15.442 16.01226 16.014 v4.14-rc8+patch 30.0 15.5033 0.189681 15.232 15.93938 15.962 ... show a 1.8% speedup on average completion time and 0.5% speedup in the 99 percentile. Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> Signed-off-by: Chris Redpath <chris.redpath@arm.com> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Reviewed-by: Brendan Jackman <brendan.jackman@arm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincent Guittot <vincent.guittot@linaro.org> Link: http://lkml.kernel.org/r/20171108184101.16006-1-patrick.bellasi@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-08Merge branch 'linus' into sched/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-10sched/rt: Simplify the IPI based RT balancing logicSteven Rostedt (Red Hat)
When a CPU lowers its priority (schedules out a high priority task for a lower priority one), a check is made to see if any other CPU has overloaded RT tasks (more than one). It checks the rto_mask to determine this and if so it will request to pull one of those tasks to itself if the non running RT task is of higher priority than the new priority of the next task to run on the current CPU. When we deal with large number of CPUs, the original pull logic suffered from large lock contention on a single CPU run queue, which caused a huge latency across all CPUs. This was caused by only having one CPU having overloaded RT tasks and a bunch of other CPUs lowering their priority. To solve this issue, commit: b6366f048e0c ("sched/rt: Use IPI to trigger RT task push migration instead of pulling") changed the way to request a pull. Instead of grabbing the lock of the overloaded CPU's runqueue, it simply sent an IPI to that CPU to do the work. Although the IPI logic worked very well in removing the large latency build up, it still could suffer from a large number of IPIs being sent to a single CPU. On a 80 CPU box, I measured over 200us of processing IPIs. Worse yet, when I tested this on a 120 CPU box, with a stress test that had lots of RT tasks scheduling on all CPUs, it actually triggered the hard lockup detector! One CPU had so many IPIs sent to it, and due to the restart mechanism that is triggered when the source run queue has a priority status change, the CPU spent minutes! processing the IPIs. Thinking about this further, I realized there's no reason for each run queue to send its own IPI. As all CPUs with overloaded tasks must be scanned regardless if there's one or many CPUs lowering their priority, because there's no current way to find the CPU with the highest priority task that can schedule to one of these CPUs, there really only needs to be one IPI being sent around at a time. This greatly simplifies the code! The new approach is to have each root domain have its own irq work, as the rto_mask is per root domain. The root domain has the following fields attached to it: rto_push_work - the irq work to process each CPU set in rto_mask rto_lock - the lock to protect some of the other rto fields rto_loop_start - an atomic that keeps contention down on rto_lock the first CPU scheduling in a lower priority task is the one to kick off the process. rto_loop_next - an atomic that gets incremented for each CPU that schedules in a lower priority task. rto_loop - a variable protected by rto_lock that is used to compare against rto_loop_next rto_cpu - The cpu to send the next IPI to, also protected by the rto_lock. When a CPU schedules in a lower priority task and wants to make sure overloaded CPUs know about it. It increments the rto_loop_next. Then it atomically sets rto_loop_start with a cmpxchg. If the old value is not "0", then it is done, as another CPU is kicking off the IPI loop. If the old value is "0", then it will take the rto_lock to synchronize with a possible IPI being sent around to the overloaded CPUs. If rto_cpu is greater than or equal to nr_cpu_ids, then there's either no IPI being sent around, or one is about to finish. Then rto_cpu is set to the first CPU in rto_mask and an IPI is sent to that CPU. If there's no CPUs set in rto_mask, then there's nothing to be done. When the CPU receives the IPI, it will first try to push any RT tasks that is queued on the CPU but can't run because a higher priority RT task is currently running on that CPU. Then it takes the rto_lock and looks for the next CPU in the rto_mask. If it finds one, it simply sends an IPI to that CPU and the process continues. If there's no more CPUs in the rto_mask, then rto_loop is compared with rto_loop_next. If they match, everything is done and the process is over. If they do not match, then a CPU scheduled in a lower priority task as the IPI was being passed around, and the process needs to start again. The first CPU in rto_mask is sent the IPI. This change removes this duplication of work in the IPI logic, and greatly lowers the latency caused by the IPIs. This removed the lockup happening on the 120 CPU machine. It also simplifies the code tremendously. What else could anyone ask for? Thanks to Peter Zijlstra for simplifying the rto_loop_start atomic logic and supplying me with the rto_start_trylock() and rto_start_unlock() helper functions. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Clark Williams <williams@redhat.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: John Kacur <jkacur@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Scott Wood <swood@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170424114732.1aac6dc4@gandalf.local.home Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-10sched/deadline: Rename __dl_clear() to __dl_sub()Peter Zijlstra
__dl_sub() is more meaningful as a name, and is more consistent with the naming of the dual function (__dl_add()). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1504778971-13573-4-git-send-email-luca.abeni@santannapisa.it Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-10sched/headers: Remove duplicate prototype of __dl_clear_params()luca abeni
Signed-off-by: luca abeni <luca.abeni@santannapisa.it> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1504778971-13573-2-git-send-email-luca.abeni@santannapisa.it Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-29sched/fair: Propagate an effective runnable_load_avgPeter Zijlstra
The load balancer uses runnable_load_avg as load indicator. For !cgroup this is: runnable_load_avg = \Sum se->avg.load_avg ; where se->on_rq That is, a direct sum of all runnable tasks on that runqueue. As opposed to load_avg, which is a sum of all tasks on the runqueue, which includes a blocked component. However, in the cgroup case, this comes apart since the group entities are always runnable, even if most of their constituent entities are blocked. Therefore introduce a runnable_weight which for task entities is the same as the regular weight, but for group entities is a fraction of the entity weight and represents the runnable part of the group runqueue. Then propagate this load through the PELT hierarchy to arrive at an effective runnable load avgerage -- which we should not confuse with the canonical runnable load average. Suggested-by: Tejun Heo <tj@kernel.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: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-29sched/fair: Rewrite PELT migration propagationPeter Zijlstra
When an entity migrates in (or out) of a runqueue, we need to add (or remove) its contribution from the entire PELT hierarchy, because even non-runnable entities are included in the load average sums. In order to do this we have some propagation logic that updates the PELT tree, however the way it 'propagates' the runnable (or load) change is (more or less): tg->weight * grq->avg.load_avg ge->avg.load_avg = ------------------------------ tg->load_avg But that is the expression for ge->weight, and per the definition of load_avg: ge->avg.load_avg := ge->weight * ge->avg.runnable_avg That destroys the runnable_avg (by setting it to 1) we wanted to propagate. Instead directly propagate runnable_sum. 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>
2017-09-29sched/fair: Rewrite cfs_rq->removed_*avgPeter Zijlstra
Since on wakeup migration we don't hold the rq->lock for the old CPU we cannot update its state. Instead we add the removed 'load' to an atomic variable and have the next update on that CPU collect and process it. Currently we have 2 atomic variables; which already have the issue that they can be read out-of-sync. Also, two atomic ops on a single cacheline is already more expensive than an uncontended lock. Since we want to add more, convert the thing over to an explicit cacheline with a lock in. 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>
2017-09-29sched/fair: Use reweight_entity() for set_user_nice()Vincent Guittot
Now that we directly change load_avg and propagate that change into the sums, sys_nice() and co should do the same, otherwise its possible to confuse load accounting when we migrate near the weight change. Fixes-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> [ Added changelog, fixed the call condition. ] 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 Link: http://lkml.kernel.org/r/20170517095045.GA8420@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-25cpuacct: Introduce cgroup_account_cputime[_field]()Tejun Heo
Introduce cgroup_account_cputime[_field]() which wrap cpuacct_charge() and cgroup_account_field(). This doesn't introduce any functional changes and will be used to add cgroup basic resource accounting. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com>
2017-09-13Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Three CPU hotplug related fixes and a debugging improvement" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/debug: Add debugfs knob for "sched_debug" sched/core: WARN() when migrating to an offline CPU sched/fair: Plug hole between hotplug and active_load_balance() sched/fair: Avoid newidle balance for !active CPUs
2017-09-12sched/debug: Add debugfs knob for "sched_debug"Peter Zijlstra
I'm forever late for editing my kernel cmdline, add a runtime knob to disable the "sched_debug" thing. 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/20170907150614.142924283@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-09-08sched/deadline: replace earliest dl and rq leftmost cachingDavidlohr Bueso
... with the generic rbtree flavor instead. No changes in semantics whatsoever. Link: http://lkml.kernel.org/r/20170719014603.19029-9-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08sched/fair: replace cfs_rq->rb_leftmostDavidlohr Bueso
... with the generic rbtree flavor instead. No changes in semantics whatsoever. Link: http://lkml.kernel.org/r/20170719014603.19029-8-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-05Merge tag 'pm-4.14-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "This time (again) cpufreq gets the majority of changes which mostly are driver updates (including a major consolidation of intel_pstate), some schedutil governor modifications and core cleanups. There also are some changes in the system suspend area, mostly related to diagnostics and debug messages plus some renames of things related to suspend-to-idle. One major change here is that suspend-to-idle is now going to be preferred over S3 on systems where the ACPI tables indicate to do so and provide requsite support (the Low Power Idle S0 _DSM in particular). The system sleep documentation and the tools related to it are updated too. The rest is a few cpuidle changes (nothing major), devfreq updates, generic power domains (genpd) framework updates and a few assorted modifications elsewhere. Specifics: - Drop the P-state selection algorithm based on a PID controller from intel_pstate and make it use the same P-state selection method (based on the CPU load) for all types of systems in the active mode (Rafael Wysocki, Srinivas Pandruvada). - Rework the cpufreq core and governors to make it possible to take cross-CPU utilization updates into account and modify the schedutil governor to actually do so (Viresh Kumar). - Clean up the handling of transition latency information in the cpufreq core and untangle it from the information on which drivers cannot do dynamic frequency switching (Viresh Kumar). - Add support for new SoCs (MT2701/MT7623 and MT7622) to the mediatek cpufreq driver and update its DT bindings (Sean Wang). - Modify the cpufreq dt-platdev driver to autimatically create cpufreq devices for the new (v2) Operating Performance Points (OPP) DT bindings and update its whitelist of supported systems (Viresh Kumar, Shubhrajyoti Datta, Marc Gonzalez, Khiem Nguyen, Finley Xiao). - Add support for Ux500 to the cpufreq-dt driver and drop the obsolete dbx500 cpufreq driver (Linus Walleij, Arnd Bergmann). - Add new SoC (R8A7795) support to the cpufreq rcar driver (Khiem Nguyen). - Fix and clean up assorted issues in the cpufreq drivers and core (Arvind Yadav, Christophe Jaillet, Colin Ian King, Gustavo Silva, Julia Lawall, Leonard Crestez, Rob Herring, Sudeep Holla). - Update the IO-wait boost handling in the schedutil governor to make it less aggressive (Joel Fernandes). - Rework system suspend diagnostics to make it print fewer messages to the kernel log by default, add a sysfs knob to allow more suspend-related messages to be printed and add Low Power S0 Idle constraints checks to the ACPI suspend-to-idle code (Rafael Wysocki, Srinivas Pandruvada). - Prefer suspend-to-idle over S3 on ACPI-based systems with the ACPI_FADT_LOW_POWER_S0 flag set and the Low Power Idle S0 _DSM interface present in the ACPI tables (Rafael Wysocki). - Update documentation related to system sleep and rename a number of items in the code to make it cleare that they are related to suspend-to-idle (Rafael Wysocki). - Export a variable allowing device drivers to check the target system sleep state from the core system suspend code (Florian Fainelli). - Clean up the cpuidle subsystem to handle the polling state on x86 in a more straightforward way and to use %pOF instead of full_name (Rafael Wysocki, Rob Herring). - Update the devfreq framework to fix and clean up a few minor issues (Chanwoo Choi, Rob Herring). - Extend diagnostics in the generic power domains (genpd) framework and clean it up slightly (Thara Gopinath, Rob Herring). - Fix and clean up a couple of issues in the operating performance points (OPP) framework (Viresh Kumar, Waldemar Rymarkiewicz). - Add support for RV1108 to the rockchip-io Adaptive Voltage Scaling (AVS) driver (David Wu). - Fix the usage of notifiers in CPU power management on some platforms (Alex Shi). - Update the pm-graph system suspend/hibernation and boot profiling utility (Todd Brandt). - Make it possible to run the cpupower utility without CPU0 (Prarit Bhargava)" * tag 'pm-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (87 commits) cpuidle: Make drivers initialize polling state cpuidle: Move polling state initialization code to separate file cpuidle: Eliminate the CPUIDLE_DRIVER_STATE_START symbol cpufreq: imx6q: Fix imx6sx low frequency support cpufreq: speedstep-lib: make several arrays static, makes code smaller PM: docs: Delete the obsolete states.txt document PM: docs: Describe high-level PM strategies and sleep states PM / devfreq: Fix memory leak when fail to register device PM / devfreq: Add dependency on PM_OPP PM / devfreq: Move private devfreq_update_stats() into devfreq PM / devfreq: Convert to using %pOF instead of full_name PM / AVS: rockchip-io: add io selectors and supplies for RV1108 cpufreq: ti: Fix 'of_node_put' being called twice in error handling path cpufreq: dt-platdev: Drop few entries from whitelist cpufreq: dt-platdev: Automatically create cpufreq device with OPP v2 ARM: ux500: don't select CPUFREQ_DT cpuidle: Convert to using %pOF instead of full_name cpufreq: Convert to using %pOF instead of full_name PM / Domains: Convert to using %pOF instead of full_name cpufreq: Cap the default transition delay value to 10 ms ...
2017-09-04Merge branch 'locking-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: - Add 'cross-release' support to lockdep, which allows APIs like completions, where it's not the 'owner' who releases the lock, to be tracked. It's all activated automatically under CONFIG_PROVE_LOCKING=y. - Clean up (restructure) the x86 atomics op implementation to be more readable, in preparation of KASAN annotations. (Dmitry Vyukov) - Fix static keys (Paolo Bonzini) - Add killable versions of down_read() et al (Kirill Tkhai) - Rework and fix jump_label locking (Marc Zyngier, Paolo Bonzini) - Rework (and fix) tlb_flush_pending() barriers (Peter Zijlstra) - Remove smp_mb__before_spinlock() and convert its usages, introduce smp_mb__after_spinlock() (Peter Zijlstra) * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (56 commits) locking/lockdep/selftests: Fix mixed read-write ABBA tests sched/completion: Avoid unnecessary stack allocation for COMPLETION_INITIALIZER_ONSTACK() acpi/nfit: Fix COMPLETION_INITIALIZER_ONSTACK() abuse locking/pvqspinlock: Relax cmpxchg's to improve performance on some architectures smp: Avoid using two cache lines for struct call_single_data locking/lockdep: Untangle xhlock history save/restore from task independence locking/refcounts, x86/asm: Disable CONFIG_ARCH_HAS_REFCOUNT for the time being futex: Remove duplicated code and fix undefined behaviour Documentation/locking/atomic: Finish the document... locking/lockdep: Fix workqueue crossrelease annotation workqueue/lockdep: 'Fix' flush_work() annotation locking/lockdep/selftests: Add mixed read-write ABBA tests mm, locking/barriers: Clarify tlb_flush_pending() barriers locking/lockdep: Make CONFIG_LOCKDEP_CROSSRELEASE and CONFIG_LOCKDEP_COMPLETIONS truly non-interactive locking/lockdep: Explicitly initialize wq_barrier::done::map locking/lockdep: Rename CONFIG_LOCKDEP_COMPLETE to CONFIG_LOCKDEP_COMPLETIONS locking/lockdep: Reword title of LOCKDEP_CROSSRELEASE config locking/lockdep: Make CONFIG_LOCKDEP_CROSSRELEASE part of CONFIG_PROVE_LOCKING locking/refcounts, x86/asm: Implement fast refcount overflow protection locking/lockdep: Fix the rollback and overwrite detection logic in crossrelease ...
2017-08-29smp: Avoid using two cache lines for struct call_single_dataYing Huang
struct call_single_data is used in IPIs to transfer information between CPUs. Its size is bigger than sizeof(unsigned long) and less than cache line size. Currently it is not allocated with any explicit alignment requirements. This makes it possible for allocated call_single_data to cross two cache lines, which results in double the number of the cache lines that need to be transferred among CPUs. This can be fixed by requiring call_single_data to be aligned with the size of call_single_data. Currently the size of call_single_data is the power of 2. If we add new fields to call_single_data, we may need to add padding to make sure the size of new definition is the power of 2 as well. Fortunately, this is enforced by GCC, which will report bad sizes. To set alignment requirements of call_single_data to the size of call_single_data, a struct definition and a typedef is used. To test the effect of the patch, I used the vm-scalability multiple thread swap test case (swap-w-seq-mt). The test will create multiple threads and each thread will eat memory until all RAM and part of swap is used, so that huge number of IPIs are triggered when unmapping memory. In the test, the throughput of memory writing improves ~5% compared with misaligned call_single_data, because of faster IPIs. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Huang, Ying <ying.huang@intel.com> [ Add call_single_data_t and align with size of call_single_data. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/87bmnqd6lz.fsf@yhuang-mobile.sh.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-25sched/debug: Optimize sched_domain sysctl generationPeter Zijlstra
Currently we unconditionally destroy all sysctl bits and regenerate them after we've rebuild the domains (even if that rebuild is a no-op). And since we unconditionally (re)build the sysctl for all possible CPUs, onlining all CPUs gets us O(n^2) time. Instead change this to only rebuild the bits for CPUs we've actually installed new domains on. Reported-by: Ofer Levi(SW) <oferle@mellanox.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-01sched: cpufreq: Allow remote cpufreq callbacksViresh Kumar
With Android UI and benchmarks the latency of cpufreq response to certain scheduling events can become very critical. Currently, callbacks into cpufreq governors are only made from the scheduler if the target CPU of the event is the same as the current CPU. This means there are certain situations where a target CPU may not run the cpufreq governor for some time. One testcase to show this behavior is where a task starts running on CPU0, then a new task is also spawned on CPU0 by a task on CPU1. If the system is configured such that the new tasks should receive maximum demand initially, this should result in CPU0 increasing frequency immediately. But because of the above mentioned limitation though, this does not occur. This patch updates the scheduler core to call the cpufreq callbacks for remote CPUs as well. The schedutil, ondemand and conservative governors are updated to process cpufreq utilization update hooks called for remote CPUs where the remote CPU is managed by the cpufreq policy of the local CPU. The intel_pstate driver is updated to always reject remote callbacks. This is tested with couple of usecases (Android: hackbench, recentfling, galleryfling, vellamo, Ubuntu: hackbench) on ARM hikey board (64 bit octa-core, single policy). Only galleryfling showed minor improvements, while others didn't had much deviation. The reason being that this patch only targets a corner case, where following are required to be true to improve performance and that doesn't happen too often with these tests: - Task is migrated to another CPU. - The task has high demand, and should take the target CPU to higher OPPs. - And the target CPU doesn't call into the cpufreq governor until the next tick. Based on initial work from Steve Muckle. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Saravana Kannan <skannan@codeaurora.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-23sched/rt: Move RT related code from sched/core.c to sched/rt.cNicolas Pitre
This helps making sched/core.c smaller and hopefully easier to understand and maintain. Signed-off-by: Nicolas Pitre <nico@linaro.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/20170621182203.30626-3-nicolas.pitre@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-23sched/deadline: Move DL related code from sched/core.c to sched/deadline.cNicolas Pitre
This helps making sched/core.c smaller and hopefully easier to understand and maintain. Signed-off-by: Nicolas Pitre <nico@linaro.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/20170621182203.30626-2-nicolas.pitre@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-20sched/debug: Fix SCHED_WARN_ON() to return a value on !CONFIG_SCHED_DEBUG as ↵Ingo Molnar
well This definition of SCHED_WARN_ON(): #define SCHED_WARN_ON(x) ((void)(x)) is not fully compatible with the 'real' WARN_ON_ONCE() primitive, as it has no return value, so it cannot be used in conditionals. Fix it. Cc: Daniel Axtens <dja@axtens.net> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> 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>
2017-06-08sched/core: Omit building stop_sched_class when !SMPNicolas Pitre
The stop class is invoked through stop_machine only. This is dead code on UP builds. Signed-off-by: Nicolas Pitre <nico@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> Link: http://lkml.kernel.org/r/20170529210302.26868-3-nicolas.pitre@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-08sched/deadline: Reclaim bandwidth not used by dl tasksLuca Abeni
This commit introduces a per-runqueue "extra utilization" that can be reclaimed by deadline tasks. In this way, the maximum fraction of CPU time that can reclaimed by deadline tasks is fixed (and configurable) and does not depend on the total deadline utilization. The GRUB accounting rule is modified to add this "extra utilization" to the inactive utilization of the runqueue, and to avoid reclaiming more than a maximum fraction of the CPU time. Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1495138417-6203-10-git-send-email-luca.abeni@santannapisa.it Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-08sched/deadline: Track the "total rq utilization" tooLuca Abeni
The total rq utilization is defined as the sum of the utilisations of tasks that are "assigned" to a runqueue, independently from their state (TASK_RUNNING or blocked) Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it> Signed-off-by: Claudio Scordino <claudio@evidence.eu.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1495138417-6203-8-git-send-email-luca.abeni@santannapisa.it Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-08sched/deadline: Do not reclaim the whole CPU bandwidthLuca Abeni
Original GRUB tends to reclaim 100% of the CPU time... And this allows a CPU hog to starve non-deadline tasks. To address this issue, allow the scheduler to reclaim only a specified fraction of CPU time, stored in the new "bw_ratio" field of the dl runqueue structure. Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1495138417-6203-6-git-send-email-luca.abeni@santannapisa.it Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-08sched/deadline: Implement GRUB accountingLuca Abeni
According to the GRUB (Greedy Reclaimation of Unused Bandwidth) reclaiming algorithm, the runtime is not decreased as "dq = -dt", but as "dq = -Uact dt" (where Uact is the per-runqueue active utilization). Hence, this commit modifies the runtime accounting rule in update_curr_dl() to implement the GRUB rule. Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1495138417-6203-5-git-send-email-luca.abeni@santannapisa.it Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-08sched/deadline: Improve the tracking of active utilizationLuca Abeni
This patch implements a more theoretically sound algorithm for tracking active utilization: instead of decreasing it when a task blocks, use a timer (the "inactive timer", named after the "Inactive" task state of the GRUB algorithm) to decrease the active utilization at the so called "0-lag time". Tested-by: Claudio Scordino <claudio@evidence.eu.com> Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Joel Fernandes <joelaf@google.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1495138417-6203-3-git-send-email-luca.abeni@santannapisa.it Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-08sched/deadline: Track the active utilizationLuca Abeni
Active utilization is defined as the total utilization of active (TASK_RUNNING) tasks queued on a runqueue. Hence, it is increased when a task wakes up and is decreased when a task blocks. When a task is migrated from CPUi to CPUj, immediately subtract the task's utilization from CPUi and add it to CPUj. This mechanism is implemented by modifying the pull and push functions. Note: this is not fully correct from the theoretical point of view (the utilization should be removed from CPUi only at the 0 lag time), a more theoretically sound solution is presented in the next patches. Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Luca Abeni <luca.abeni@unitn.it> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@arm.com> Cc: Claudio Scordino <claudio@evidence.eu.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Link: http://lkml.kernel.org/r/1495138417-6203-2-git-send-email-luca.abeni@santannapisa.it Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-15sched/topology: Rename sched_group_cpus()Peter Zijlstra
There's a discrepancy in naming between the sched_domain and sched_group cpumask accessor. Since we're doing changes, fix it. $ git grep sched_group_cpus | wc -l 28 $ git grep sched_domain_span | wc -l 38 Suggests changing sched_group_cpus() into sched_group_span(): for i in `git grep -l sched_group_cpus` do sed -ie 's/sched_group_cpus/sched_group_span/g' $i done 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>
2017-05-15sched/topology: Rename sched_group_mask()Peter Zijlstra
Since sched_group_mask() is now an independent cpumask (it no longer masks sched_group_cpus()), rename the thing. Suggested-by: Lauro Ramos Venancio <lvenanci@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-15sched/topology: Add sched_group_capacity debuggingPeter Zijlstra
Add sgc::id to easier spot domain construction issues. Take the opportunity to slightly rework the group printing, because adding more "(id: %d)" strings makes the entire thing very hard to read. Also the individual groups are very hard to separate, so add explicit visual grouping, which allows replacing all the "(%s: %d)" format things with shorter "%s=%d" variants. Then fix up some inconsistencies in surrounding prints for domains. The end result looks like: [] CPU0 attaching sched-domain(s): [] domain-0: span=0,4 level=DIE [] groups: 0:{ span=0 }, 4:{ span=4 } [] domain-1: span=0-1,3-5,7 level=NUMA [] groups: 0:{ span=0,4 mask=0,4 cap=2048 }, 1:{ span=1,5 mask=1,5 cap=2048 }, 3:{ span=3,7 mask=3,7 cap=2048 } [] domain-2: span=0-7 level=NUMA [] groups: 0:{ span=0-1,3-5,7 mask=0,4 cap=6144 }, 2:{ span=1-3,5-7 mask=2,6 cap=6144 } 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>
2017-05-15sched/topology: Small cleanupPeter Zijlstra
Move the allocation of topology specific cpumasks into the topology code. 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>
2017-05-15sched/core: Call __schedule() from do_idle() without enabling preemptionSteven Rostedt (VMware)
I finally got around to creating trampolines for dynamically allocated ftrace_ops with using synchronize_rcu_tasks(). For users of the ftrace function hook callbacks, like perf, that allocate the ftrace_ops descriptor via kmalloc() and friends, ftrace was not able to optimize the functions being traced to use a trampoline because they would also need to be allocated dynamically. The problem is that they cannot be freed when CONFIG_PREEMPT is set, as there's no way to tell if a task was preempted on the trampoline. That was before Paul McKenney implemented synchronize_rcu_tasks() that would make sure all tasks (except idle) have scheduled out or have entered user space. While testing this, I triggered this bug: BUG: unable to handle kernel paging request at ffffffffa0230077 ... RIP: 0010:0xffffffffa0230077 ... Call Trace: schedule+0x5/0xe0 schedule_preempt_disabled+0x18/0x30 do_idle+0x172/0x220 What happened was that the idle task was preempted on the trampoline. As synchronize_rcu_tasks() ignores the idle thread, there's nothing that lets ftrace know that the idle task was preempted on a trampoline. The idle task shouldn't need to ever enable preemption. The idle task is simply a loop that calls schedule or places the cpu into idle mode. In fact, having preemption enabled is inefficient, because it can happen when idle is just about to call schedule anyway, which would cause schedule to be called twice. Once for when the interrupt came in and was returning back to normal context, and then again in the normal path that the idle loop is running in, which would be pointless, as it had already scheduled. The only reason schedule_preempt_disable() enables preemption is to be able to call sched_submit_work(), which requires preemption enabled. As this is a nop when the task is in the RUNNING state, and idle is always in the running state, there's no reason that idle needs to enable preemption. But that means it cannot use schedule_preempt_disable() as other callers of that function require calling sched_submit_work(). Adding a new function local to kernel/sched/ that allows idle to call the scheduler without enabling preemption, fixes the synchronize_rcu_tasks() issue, as well as removes the pointless spurious schedule calls caused by interrupts happening in the brief window where preemption is enabled just before it calls schedule. Reviewed: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170414084809.3dacde2a@gandalf.local.home Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-01Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes in this cycle were: - another round of rq-clock handling debugging, robustization and fixes - PELT accounting improvements - CPU hotplug related ->cpus_allowed affinity handling fixes all around the tree - ... plus misc fixes, cleanups and updates" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits) sched/x86: Update reschedule warning text crypto: N2 - Replace racy task affinity logic cpufreq/sparc-us2e: Replace racy task affinity logic cpufreq/sparc-us3: Replace racy task affinity logic cpufreq/sh: Replace racy task affinity logic cpufreq/ia64: Replace racy task affinity logic ACPI/processor: Replace racy task affinity logic ACPI/processor: Fix error handling in __acpi_processor_start() sparc/sysfs: Replace racy task affinity logic powerpc/smp: Replace open coded task affinity logic ia64/sn/hwperf: Replace racy task affinity logic ia64/salinfo: Replace racy task affinity logic workqueue: Provide work_on_cpu_safe() ia64/topology: Remove cpus_allowed manipulation sched/fair: Move the PELT constants into a generated header sched/fair: Increase PELT accuracy for small tasks sched/fair: Fix comments sched/Documentation: Add 'sched-pelt' tool sched/fair: Fix corner case in __accumulate_sum() sched/core: Remove 'task' parameter and rename tsk_restore_flags() to current_restore_flags() ...
2017-04-27sched/cputime: Fix ksoftirqd cputime accounting regressionFrederic Weisbecker
irq_time_read() returns the irqtime minus the ksoftirqd time. This is necessary because irq_time_read() is used to substract the IRQ time from the sum_exec_runtime of a task. If we were to include the softirq time of ksoftirqd, this task would substract its own CPU time everytime it updates ksoftirqd->sum_exec_runtime which would therefore never progress. But this behaviour got broken by: a499a5a14db ("sched/cputime: Increment kcpustat directly on irqtime account") ... which now includes ksoftirqd softirq time in the time returned by irq_time_read(). This has resulted in wrong ksoftirqd cputime reported to userspace through /proc/stat and thus "top" not showing ksoftirqd when it should after intense networking load. ksoftirqd->stime happens to be correct but it gets scaled down by sum_exec_runtime through task_cputime_adjusted(). To fix this, just account the strict IRQ time in a separate counter and use it to report the IRQ time. Reported-and-tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1493129448-5356-1-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16sched/core: Add {EN,DE}QUEUE_NOCLOCK flagsPeter Zijlstra
Currently {en,de}queue_task() do an unconditional update_rq_clock(). However since we want to avoid duplicate updates, so that each rq->lock section appears atomic in time, we need to be able to skip these clock updates. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-16sched/core: Add rq->lock wrappersPeter Zijlstra
The missing update_rq_clock() check can work with partial rq->lock wrappery, since a missing wrapper can cause the warning to not be emitted when it should have, but cannot cause the warning to trigger when it should not have. The duplicate update_rq_clock() check however can cause false warnings to trigger. Therefore add more comprehensive rq->lock wrappery. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02sched/headers: Prepare to move _init() prototypes from <linux/sched.h> to ↵Ingo Molnar
<linux/sched/init.h> But first introduce a trivial header and update usage sites. Acked-by: 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>
2017-03-02sched/headers: Prepare to move cputime functionality from <linux/sched.h> ↵Ingo Molnar
into <linux/sched/cputime.h> Introduce a trivial, mostly empty <linux/sched/cputime.h> header to prepare for the moving of cputime functionality out of sched.h. Update all code that relies on these facilities. Acked-by: 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>
2017-03-02sched/headers: Prepare to move the 'root_task_group' declaration to ↵Ingo Molnar
<linux/sched/autogroup.h> Acked-by: 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>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/task_stack.h> We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task_stack.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: 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>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/task.h> We are going to split <linux/sched/task.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: 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>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/hotplug.h> We are going to split <linux/sched/hotplug.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/hotplug.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: 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>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/debug.h> We are going to split <linux/sched/debug.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/debug.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: 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>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/nohz.h> We are going to split <linux/sched/nohz.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/nohz.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: 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>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/stat.h> We are going to split <linux/sched/stat.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/stat.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: 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>
2017-03-02sched/headers: Prepare header dependency changes, move the <asm/paravirt.h> ↵Ingo Molnar
include to kernel/sched/sched.h Recent header reorganizations unearthed this hidden dependency: kernel/sched/core.c:199:25: error: 'paravirt_steal_rq_enabled' undeclared (first use in this function) kernel/sched/core.c:200:11: error: implicit declaration of function 'paravirt_steal_clock' [-Werror=implicit-function-declaration] So move the asm/paravirt.h include from kernel/sched/cpuclock.c to kernel/sched/sched.h. ( NOTE: We do this change before doing the changes that introduce the build failure, so the series remains fully bisectable. ) Reported-by: kbuild test robot <fengguang.wu@intel.com> Acked-by: 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>