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* sched/rt: Fix live lock between select_fallback_rq() and RT pushJoel Fernandes (Google)2023-09-281-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During RCU-boost testing with the TREE03 rcutorture config, I found that after a few hours, the machine locks up. On tracing, I found that there is a live lock happening between 2 CPUs. One CPU has an RT task running, while another CPU is being offlined which also has an RT task running. During this offlining, all threads are migrated. The migration thread is repeatedly scheduled to migrate actively running tasks on the CPU being offlined. This results in a live lock because select_fallback_rq() keeps picking the CPU that an RT task is already running on only to get pushed back to the CPU being offlined. It is anyway pointless to pick CPUs for pushing tasks to if they are being offlined only to get migrated away to somewhere else. This could also add unwanted latency to this task. Fix these issues by not selecting CPUs in RT if they are not 'active' for scheduling, using the cpu_active_mask. Other parts in core.c already use cpu_active_mask to prevent tasks from being put on CPUs going offline. With this fix I ran the tests for days and could not reproduce the hang. Without the patch, I hit it in a few hours. Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Paul E. McKenney <paulmck@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230923011409.3522762-1-joel@joelfernandes.org
* sched/all: Change all BUG_ON() instances in the scheduler to WARN_ON_ONCE()Ingo Molnar2022-08-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | There's no good reason to crash a user's system with a BUG_ON(), chances are high that they'll never even see the crash message on Xorg, and it won't make it into the syslog either. By using a WARN_ON_ONCE() we at least give the user a chance to report any bugs triggered here - instead of getting silent hangs. None of these WARN_ON_ONCE()s are supposed to trigger, ever - so we ignore cases where a NULL check is done via a BUG_ON() and we let a NULL pointer through after a WARN_ON_ONCE(). There's one exception: WARN_ON_ONCE() arguments with side-effects, such as locking - in this case we use the return value of the WARN_ON_ONCE(), such as in: - BUG_ON(!lock_task_sighand(p, &flags)); + if (WARN_ON_ONCE(!lock_task_sighand(p, &flags))) + return; Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/YvSsKcAXISmshtHo@gmail.com
* sched/headers: Introduce kernel/sched/build_utility.c and build multiple .c ↵Ingo Molnar2022-02-231-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | files there Collect all utility functionality source code files into a single kernel/sched/build_utility.c file, via #include-ing the .c files: kernel/sched/clock.c kernel/sched/completion.c kernel/sched/loadavg.c kernel/sched/swait.c kernel/sched/wait_bit.c kernel/sched/wait.c CONFIG_CPU_FREQ: kernel/sched/cpufreq.c CONFIG_CPU_FREQ_GOV_SCHEDUTIL: kernel/sched/cpufreq_schedutil.c CONFIG_CGROUP_CPUACCT: kernel/sched/cpuacct.c CONFIG_SCHED_DEBUG: kernel/sched/debug.c CONFIG_SCHEDSTATS: kernel/sched/stats.c CONFIG_SMP: kernel/sched/cpupri.c kernel/sched/stop_task.c kernel/sched/topology.c CONFIG_SCHED_CORE: kernel/sched/core_sched.c CONFIG_PSI: kernel/sched/psi.c CONFIG_MEMBARRIER: kernel/sched/membarrier.c CONFIG_CPU_ISOLATION: kernel/sched/isolation.c CONFIG_SCHED_AUTOGROUP: kernel/sched/autogroup.c The goal is to amortize the 60+ KLOC header bloat from over a dozen build units into a single build unit. The build time of build_utility.c also roughly matches the build time of core.c and fair.c - allowing better load-balancing of scheduler-only rebuilds. Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Peter Zijlstra <peterz@infradead.org>
* sched: Fix various typosIngo Molnar2021-03-221-2/+2
| | | | | | | | | | | | | | | | | Fix ~42 single-word typos in scheduler code comments. We have accumulated a few fun ones over the years. :-) Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: linux-kernel@vger.kernel.org
* Merge branch 'sched/migrate-disable'Peter Zijlstra2020-11-101-2/+2
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| * sched,rt: Use the full cpumask for balancingPeter Zijlstra2020-11-101-2/+2
| | | | | | | | | | | | | | | | | | | | We want migrate_disable() tasks to get PULLs in order for them to PUSH away the higher priority task. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Link: https://lkml.kernel.org/r/20201023102347.310519774@infradead.org
* | sched/cpupri: Add CPUPRI_HIGHERPeter Zijlstra2020-10-291-3/+9
| | | | | | | | | | | | | | | | | | | | | | Add CPUPRI_HIGHER above the RT99 priority to denote the CPU is in use by higher priority tasks (specifically deadline). XXX: we should probably drive PUSH-PULL from cpupri, that would automagically result in an RT-PUSH when DL sets cpupri to CPUPRI_HIGHER. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
* | sched/cpupri: Remap CPUPRI_NORMAL to MAX_RT_PRIO-1Peter Zijlstra2020-10-291-7/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This makes the mapping continuous and frees up 100 for other usage. Prev mapping: p->rt_priority p->prio newpri cpupri -1 -1 (CPUPRI_INVALID) 100 0 (CPUPRI_NORMAL) 1 98 98 1 ... 49 50 50 49 50 49 49 50 ... 99 0 0 99 New mapping: p->rt_priority p->prio newpri cpupri -1 -1 (CPUPRI_INVALID) 99 0 (CPUPRI_NORMAL) 1 98 98 1 ... 49 50 50 49 50 49 49 50 ... 99 0 0 99 Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
* | sched/cpupri: Remove pri_to_cpu[1]Dietmar Eggemann2020-10-291-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pri_to_cpu[1] isn't used since cpupri_set(..., newpri) is never called with newpri = 99. The valid RT priorities RT1..RT99 (p->rt_priority = [1..99]) map into cpupri (idx of pri_to_cpu[]) = [2..100] Current mapping: p->rt_priority p->prio newpri cpupri -1 -1 (CPUPRI_INVALID) 100 0 (CPUPRI_NORMAL) 1 98 98 2 ... 49 50 50 50 50 49 49 51 ... 99 0 0 100 So cpupri = 1 isn't used. Reduce the size of pri_to_cpu[] by 1 and adapt the cpupri implementation accordingly. This will save a useless for loop with an atomic_read in cpupri_find_fitness() calling __cpupri_find(). New mapping: p->rt_priority p->prio newpri cpupri -1 -1 (CPUPRI_INVALID) 100 0 (CPUPRI_NORMAL) 1 98 98 1 ... 49 50 50 49 50 49 49 50 ... 99 0 0 99 Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200922083934.19275-3-dietmar.eggemann@arm.com
* | sched/cpupri: Remove pri_to_cpu[CPUPRI_IDLE]Dietmar Eggemann2020-10-291-6/+4
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pri_to_cpu[CPUPRI_IDLE=0] isn't used since cpupri_set(..., newpri) is never called with newpri = MAX_PRIO (140). Current mapping: p->rt_priority p->prio newpri cpupri -1 -1 (CPUPRI_INVALID) 140 0 (CPUPRI_IDLE) 100 1 (CPUPRI_NORMAL) 1 98 98 3 ... 49 50 50 51 50 49 49 52 ... 99 0 0 101 Even when cpupri was introduced with commit 6e0534f27819 ("sched: use a 2-d bitmap for searching lowest-pri CPU") in v2.6.27, only (1) CPUPRI_INVALID (-1), (2) MAX_RT_PRIO (100), (3) an RT prio (RT1..RT99) were used as newprio in cpupri_set(..., newpri) -> convert_prio(newpri). MAX_RT_PRIO is used only in dec_rt_tasks() -> dec_rt_prio() -> dec_rt_prio_smp() -> cpupri_set() in case of !rt_rq->rt_nr_running. I.e. it stands for a non-rt task, including the IDLE task. Commit 57785df5ac53 ("sched: Fix task priority bug") removed code in v2.6.33 which did set the priority of the IDLE task to MAX_PRIO. Although this happened after the introduction of cpupri, it didn't have an effect on the values used for cpupri_set(..., newpri). Remove CPUPRI_IDLE and adapt the cpupri implementation accordingly. This will save a useless for loop with an atomic_read in cpupri_find_fitness() calling __cpupri_find(). New mapping: p->rt_priority p->prio newpri cpupri -1 -1 (CPUPRI_INVALID) 100 0 (CPUPRI_NORMAL) 1 98 98 2 ... 49 50 50 50 50 49 49 51 ... 99 0 0 100 Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200922083934.19275-2-dietmar.eggemann@arm.com
* sched/rt: cpupri_find: Trigger a full search as fallbackQais Yousef2020-03-201-23/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we failed to find a fitting CPU, in cpupri_find(), we only fallback to the level we found a hit at. But Steve suggested to fallback to a second full scan instead as this could be a better effort. https://lore.kernel.org/lkml/20200304135404.146c56eb@gandalf.local.home/ We trigger the 2nd search unconditionally since the argument about triggering a full search is that the recorded fall back level might have become empty by then. Which means storing any data about what happened would be meaningless and stale. I had a humble try at timing it and it seemed okay for the small 6 CPUs system I was running on https://lore.kernel.org/lkml/20200305124324.42x6ehjxbnjkklnh@e107158-lin.cambridge.arm.com/ On large system this second full scan could be expensive. But there are no users outside capacity awareness for this fitness function at the moment. Heterogeneous systems tend to be small with 8cores in total. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Qais Yousef <qais.yousef@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lkml.kernel.org/r/20200310142219.syxzn5ljpdxqtbgx@e107158-lin.cambridge.arm.com
* sched/rt: Optimize cpupri_find() on non-heterogenous systemsQais Yousef2020-03-061-2/+8
| | | | | | | | | | | | | | | | | | By introducing a new cpupri_find_fitness() function that takes the fitness_fn as an argument and only called when asym_system static key is enabled. cpupri_find() is now a wrapper function that calls cpupri_find_fitness() passing NULL as a fitness_fn, hence disabling the logic that handles fitness by default. LINK: https://lore.kernel.org/lkml/c0772fca-0a4b-c88d-fdf2-5715fcf8447b@arm.com/ Reported-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Qais Yousef <qais.yousef@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Fixes: 804d402fb6f6 ("sched/rt: Make RT capacity-aware") Link: https://lkml.kernel.org/r/20200302132721.8353-4-qais.yousef@arm.com
* sched/rt: cpupri_find: Implement fallback mechanism for !fit caseQais Yousef2020-03-061-56/+101
| | | | | | | | | | | | | | | | | | | | | | | | | | When searching for the best lowest_mask with a fitness_fn passed, make sure we record the lowest_level that returns a valid lowest_mask so that we can use that as a fallback in case we fail to find a fitting CPU at all levels. The intention in the original patch was not to allow a down migration to unfitting CPU. But this missed the case where we are already running on unfitting one. With this change now RT tasks can still move between unfitting CPUs when they're already running on such CPU. And as Steve suggested; to adhere to the strict priority rules of RT, if a task is already running on a fitting CPU but due to priority it can't run on it, allow it to downmigrate to unfitting CPU so it can run. Reported-by: Pavan Kondeti <pkondeti@codeaurora.org> Signed-off-by: Qais Yousef <qais.yousef@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Fixes: 804d402fb6f6 ("sched/rt: Make RT capacity-aware") Link: https://lkml.kernel.org/r/20200302132721.8353-2-qais.yousef@arm.com Link: https://lore.kernel.org/lkml/20200203142712.a7yvlyo2y3le5cpn@e107158-lin/
* sched/rt: Make RT capacity-awareQais Yousef2019-12-251-2/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Capacity Awareness refers to the fact that on heterogeneous systems (like Arm big.LITTLE), the capacity of the CPUs is not uniform, hence when placing tasks we need to be aware of this difference of CPU capacities. In such scenarios we want to ensure that the selected CPU has enough capacity to meet the requirement of the running task. Enough capacity means here that capacity_orig_of(cpu) >= task.requirement. The definition of task.requirement is dependent on the scheduling class. For CFS, utilization is used to select a CPU that has >= capacity value than the cfs_task.util. capacity_orig_of(cpu) >= cfs_task.util DL isn't capacity aware at the moment but can make use of the bandwidth reservation to implement that in a similar manner CFS uses utilization. The following patchset implements that: https://lore.kernel.org/lkml/20190506044836.2914-1-luca.abeni@santannapisa.it/ capacity_orig_of(cpu)/SCHED_CAPACITY >= dl_deadline/dl_runtime For RT we don't have a per task utilization signal and we lack any information in general about what performance requirement the RT task needs. But with the introduction of uclamp, RT tasks can now control that by setting uclamp_min to guarantee a minimum performance point. ATM the uclamp value are only used for frequency selection; but on heterogeneous systems this is not enough and we need to ensure that the capacity of the CPU is >= uclamp_min. Which is what implemented here. capacity_orig_of(cpu) >= rt_task.uclamp_min Note that by default uclamp.min is 1024, which means that RT tasks will always be biased towards the big CPUs, which make for a better more predictable behavior for the default case. Must stress that the bias acts as a hint rather than a definite placement strategy. For example, if all big cores are busy executing other RT tasks we can't guarantee that a new RT task will be placed there. On non-heterogeneous systems the original behavior of RT should be retained. Similarly if uclamp is not selected in the config. [ mingo: Minor edits to comments. ] Signed-off-by: Qais Yousef <qais.yousef@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20191009104611.15363-1-qais.yousef@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge tag 'v5.2-rc5' into sched/core, to pick up fixesIngo Molnar2019-06-171-5/+1
|\ | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441Thomas Gleixner2019-06-051-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 315 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | sched/core: Provide a pointer to the valid CPU maskSebastian Andrzej Siewior2019-06-031-2/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit: 4b53a3412d66 ("sched/core: Remove the tsk_nr_cpus_allowed() wrapper") the tsk_nr_cpus_allowed() wrapper was removed. There was not much difference in !RT but in RT we used this to implement migrate_disable(). Within a migrate_disable() section the CPU mask is restricted to single CPU while the "normal" CPU mask remains untouched. As an alternative implementation Ingo suggested to use: struct task_struct { const cpumask_t *cpus_ptr; cpumask_t cpus_mask; }; with t->cpus_ptr = &t->cpus_mask; In -RT we then can switch the cpus_ptr to: t->cpus_ptr = &cpumask_of(task_cpu(p)); in a migration disabled region. The rules are simple: - Code that 'uses' ->cpus_allowed would use the pointer. - Code that 'modifies' ->cpus_allowed would use the direct mask. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190423142636.14347-1-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/headers: Simplify and clean up header usage in the schedulerIngo Molnar2018-03-041-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* sched: Clean up and harmonize the coding style of the scheduler code baseIngo Molnar2018-03-031-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* sched/cpupri: Don't re-initialize 'struct cpupri'Viresh Kumar2017-08-101-2/+0
| | | | | | | | | | | | | | | The 'struct cpupri' passed to cpupri_init() is already initialized to zero. Don't do that again. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: linaro-kernel@lists.linaro.org Link: http://lkml.kernel.org/r/8a71d48c5a077500b6ddc1a41484c0ac8d3aad94.1492065513.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/core: Remove the tsk_cpus_allowed() wrapperIngo Molnar2017-03-021-2/+2
| | | | | | | | | | | | | | | | | So the original intention of tsk_cpus_allowed() was to 'future-proof' the field - but it's pretty ineffectual at that, because half of the code uses ->cpus_allowed directly ... Also, the wrapper makes the code longer than the original expression! So just get rid of it. This also shrinks <linux/sched.h> a bit. 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>
* sched/core: Use tsk_cpus_allowed() instead of accessing ->cpus_allowedThomas Gleixner2016-05-121-2/+2
| | | | | | | | | | | | | | Use the future-safe accessor for struct task_struct's. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> 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: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1462969411-17735-1-git-send-email-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'locking-core-for-linus' of ↵Linus Torvalds2014-06-031-3/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next Pull core locking updates from Ingo Molnar: "The main changes in this cycle were: - reduced/streamlined smp_mb__*() interface that allows more usecases and makes the existing ones less buggy, especially in rarer architectures - add rwsem implementation comments - bump up lockdep limits" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits) rwsem: Add comments to explain the meaning of the rwsem's count field lockdep: Increase static allocations arch: Mass conversion of smp_mb__*() arch,doc: Convert smp_mb__*() arch,xtensa: Convert smp_mb__*() arch,x86: Convert smp_mb__*() arch,tile: Convert smp_mb__*() arch,sparc: Convert smp_mb__*() arch,sh: Convert smp_mb__*() arch,score: Convert smp_mb__*() arch,s390: Convert smp_mb__*() arch,powerpc: Convert smp_mb__*() arch,parisc: Convert smp_mb__*() arch,openrisc: Convert smp_mb__*() arch,mn10300: Convert smp_mb__*() arch,mips: Convert smp_mb__*() arch,metag: Convert smp_mb__*() arch,m68k: Convert smp_mb__*() arch,m32r: Convert smp_mb__*() arch,ia64: Convert smp_mb__*() ...
| * arch: Mass conversion of smp_mb__*()Peter Zijlstra2014-04-181-3/+3
| | | | | | | | | | | | | | | | | | | | | | Mostly scripted conversion of the smp_mb__* barriers. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-arch@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched/cpupri: Replace NR_CPUS arraysPeter Zijlstra2014-05-221-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tejun reported that his resume was failing due to order-3 allocations from sched_domain building. Replace the NR_CPUS arrays in there with a dynamically allocated array. Reported-by: Tejun Heo <tj@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-7cysnkw1gik45r864t1nkudh@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched: Use CPUPRI_NR_PRIORITIES instead of MAX_RT_PRIO in cpupri checkSteven Rostedt (Red Hat)2014-05-071-2/+1
|/ | | | | | | | | | | | | | | | | | The check at the beginning of cpupri_find() makes sure that the task_pri variable does not exceed the cp->pri_to_cpu array length. But that length is CPUPRI_NR_PRIORITIES not MAX_RT_PRIO, where it will miss the last two priorities in that array. As task_pri is computed from convert_prio() which should never be bigger than CPUPRI_NR_PRIORITIES, if the check should cause a panic if it is hit. Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1397015410.5212.13.camel@marge.simpson.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched: Fix some kernel-doc warningsYacine Belkadi2013-07-181-2/+2
| | | | | | | | | | | | | | | | | | | When building the htmldocs (in verbose mode), scripts/kernel-doc reports the follwing type of warnings: Warning(kernel/sched/core.c:936): No description found for return value of 'task_curr' ... Fix those by: - adding the missing descriptions - using "Return" sections for the descriptions Signed-off-by: Yacine Belkadi <yacine.belkadi.1@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1373654747-2389-1-git-send-email-yacine.belkadi.1@gmail.com [ While at it, fix the cpupri_set() explanation. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched/rt: Move rt specific bits into new header fileClark Williams2013-02-071-0/+2
| | | | | | | | | | | Move rt scheduler definitions out of include/linux/sched.h into new file include/linux/sched/rt.h Signed-off-by: Clark Williams <williams@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20130207094707.7b9f825f@riff.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* sched: Fix minor code style issuesYing Xue2012-07-261-5/+5
| | | | | | | | | Delete redudant spaces between type name and data name or operators. Signed-off-by: Ying Xue <ying.xue0@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1342076622-6606-1-git-send-email-ying.xue0@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* kernel-doc: fix kernel-doc warnings in schedRandy Dunlap2012-01-231-2/+1
| | | | | | | | | | | | | | | Fix new kernel-doc notation warnings: Warning(include/linux/sched.h:2094): No description found for parameter 'p' Warning(include/linux/sched.h:2094): Excess function parameter 'tsk' description in 'is_idle_task' Warning(kernel/sched/cpupri.c:139): No description found for parameter 'newpri' Warning(kernel/sched/cpupri.c:139): Excess function parameter 'pri' description in 'cpupri_set' Warning(kernel/sched/cpupri.c:208): Excess function parameter 'bootmem' description in 'cpupri_init' Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched: Move all scheduler bits into kernel/sched/Peter Zijlstra2011-11-171-0/+241
There's too many sched*.[ch] files in kernel/, give them their own directory. (No code changed, other than Makefile glue added.) Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>