- 26 4月, 2012 1 次提交
-
-
由 Peter Zijlstra 提交于
Commits 367456c7 ("sched: Ditch per cgroup task lists for load-balancing") and 5d6523eb ("sched: Fix load-balance wreckage") left some more wreckage. By setting loop_max unconditionally to ->nr_running load-balancing could take a lot of time on very long runqueues (hackbench!). So keep the sysctl as max limit of the amount of tasks we'll iterate. Furthermore, the min load filter for migration completely fails with cgroups since inequality in per-cpu state can easily lead to such small loads :/ Furthermore the change to add new tasks to the tail of the queue instead of the head seems to have some effect.. not quite sure I understand why. Combined these fixes solve the huge hackbench regression reported by Tim when hackbench is ran in a cgroup. Reported-by: NTim Chen <tim.c.chen@linux.intel.com> Acked-by: NTim Chen <tim.c.chen@linux.intel.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1335365763.28150.267.camel@twins [ got rid of the CONFIG_PREEMPT tuning and made small readability edits ] Signed-off-by: NIngo Molnar <mingo@kernel.org>
-
- 31 3月, 2012 1 次提交
-
-
由 Srivatsa S. Bhat 提交于
The function for_each_cpu_mask() expects a *pointer* to struct cpumask as its second argument, whereas select_fallback_rq() passes the value itself. And moreover, for_each_cpu_mask() has been marked as obselete in include/linux/cpumask.h. So move to the more appropriate for_each_cpu() variant. Reported-by: NSasha Levin <levinsasha928@gmail.com> Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Dave Jones <davej@redhat.com> Cc: Liu Chuansheng <chuansheng.liu@intel.com> Cc: vapier@gentoo.org Cc: rusty@rustcorp.com.au Link: http://lkml.kernel.org/r/4F75BED4.9050005@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 29 3月, 2012 2 次提交
-
-
由 Stephen Boyd 提交于
If schedule is called from an interrupt handler __schedule_bug() will call show_regs() with the registers saved during the interrupt handling done in do_IRQ(). This means we'll see the registers and the backtrace for the process that was interrupted and not the full backtrace explaining who called schedule(). This is due to 838225b4 ("sched: use show_regs() to improve __schedule_bug() output", 2007-10-24) which improperly assumed that get_irq_regs() would return the registers for the current stack because it is being called from within an interrupt handler. Simply remove the show_reg() code so that we dump a backtrace for the interrupt handler that called schedule(). [ I ran across this when I was presented with a scheduling while atomic log with a stacktrace pointing at spin_unlock_irqrestore(). It made no sense and I had to guess what interrupt handler could be called and poke around for someone calling schedule() in an interrupt handler. A simple test of putting an msleep() in an interrupt handler works better with this patch because you can actually see the msleep() call in the backtrace. ] Also-reported-by: NChris Metcalf <cmetcalf@tilera.com> Signed-off-by: NStephen Boyd <sboyd@codeaurora.org> Cc: Satyam Sharma <satyam@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1332979847-27102-1-git-send-email-sboyd@codeaurora.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 David Howells 提交于
asm/system.h is a cause of circular dependency problems because it contains commonly used primitive stuff like barrier definitions and uncommonly used stuff like switch_to() that might require MMU definitions. asm/system.h has been disintegrated by this point on all arches into the following common segments: (1) asm/barrier.h Moved memory barrier definitions here. (2) asm/cmpxchg.h Moved xchg() and cmpxchg() here. #included in asm/atomic.h. (3) asm/bug.h Moved die() and similar here. (4) asm/exec.h Moved arch_align_stack() here. (5) asm/elf.h Moved AT_VECTOR_SIZE_ARCH here. (6) asm/switch_to.h Moved switch_to() here. Signed-off-by: NDavid Howells <dhowells@redhat.com>
-
- 27 3月, 2012 2 次提交
-
-
由 Michael J Wang 提交于
Avoid extra work by continuing on to the next rt_rq if the highest prio task in current rt_rq is the same priority as our candidate task. More detailed explanation: if next is not NULL, then we have found a candidate task, and its priority is next->prio. Now we are looking for an even higher priority task in the other rt_rq's. idx is the highest priority in the current candidate rt_rq. In the current 3.3 code, if idx is equal to next->prio, we would start scanning the tasks in that rt_rq and replace the current candidate task with a task from that rt_rq. But the new task would only have a priority that is equal to our previous candidate task, so we have not advanced our goal of finding a higher prio task. So we should avoid the extra work by continuing on to the next rt_rq if idx is equal to next->prio. Signed-off-by: NMichael J Wang <mjwang@broadcom.com> Acked-by: NSteven Rostedt <rostedt@goodmis.org> Reviewed-by: NYong Zhang <yong.zhang0@gmail.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/2EF88150C0EF2C43A218742ED384C1BC0FC83D6B@IRVEXCHMB08.corp.ad.broadcom.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Peter Zijlstra 提交于
Commit 5fbd036b ("sched: Cleanup cpu_active madness"), which was supposed to finally sort the cpu_active mess, instead uncovered more. Since CPU_STARTING is ran before setting the cpu online, there's a (small) window where the cpu has active,!online. If during this time there's a wakeup of a task that used to reside on that cpu select_task_rq() will use select_fallback_rq() to compute an alternative cpu to run on since we find !online. select_fallback_rq() however will compute the new cpu against cpu_active, this means that it can return the same cpu it started out with, the !online one, since that cpu is in fact marked active. This results in us trying to scheduling a task on an offline cpu and triggering a WARN in the IPI code. The solution proposed by Chuansheng Liu of setting cpu_active in set_cpu_online() is buggy, firstly not all archs actually use set_cpu_online(), secondly, not all archs call set_cpu_online() with IRQs disabled, this means we would introduce either the same race or the race from fd8a7de1 ("x86: cpu-hotplug: Prevent softirq wakeup on wrong CPU") -- albeit much narrower. [ By setting online first and active later we have a window of online,!active, fresh and bound kthreads have task_cpu() of 0 and since cpu0 isn't in tsk_cpus_allowed() we end up in select_fallback_rq() which excludes !active, resulting in a reset of ->cpus_allowed and the thread running all over the place. ] The solution is to re-work select_fallback_rq() to require active _and_ online. This makes the active,!online case work as expected, OTOH archs running CPU_STARTING after setting online are now vulnerable to the issue from fd8a7de1 -- these are alpha and blackfin. Reported-by: NChuansheng Liu <chuansheng.liu@intel.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Frysinger <vapier@gentoo.org> Cc: linux-alpha@vger.kernel.org Link: http://lkml.kernel.org/n/tip-hubqk1i10o4dpvlm06gq7v6j@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 23 3月, 2012 1 次提交
-
-
由 Peter Zijlstra 提交于
kernel/sched/fair.c:420: warning: 'account_cfs_rq_runtime' declared inline after being called kernel/sched/fair.c:420: warning: previous declaration of 'account_cfs_rq_runtime' was here kernel/sched/fair.c:1165: warning: 'return_cfs_rq_runtime' declared inlineafter being called kernel/sched/fair.c:1165: warning: previous declaration of 'return_cfs_rq_runtime' was here Reported-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20120321200717.49BB4A024E@akpm.mtv.corp.google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 13 3月, 2012 7 次提交
-
-
由 Catalin Marinas 提交于
This callback is called by the scheduler after rq->lock has been released and interrupts enabled. It will be used in subsequent patches on the ARM architecture. Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com> Reviewed-by: NWill Deacon <will.deacon@arm.com> Reviewed-by: NFrank Rowand <frank.rowand@am.sony.com> Tested-by: NWill Deacon <will.deacon@arm.com> Tested-by: NMarc Zyngier <Marc.Zyngier@arm.com> Acked-by: NPeter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/20120313110840.7b444deb6b1bb902c15f3cdf@canb.auug.org.auSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Peter Zijlstra 提交于
Various people reported nohz load tracking still being wrecked, but Doug spotted the actual problem. We fold the nohz remainder in too soon, causing us to loose samples and under-account. So instead of playing catch-up up-front, always do a single load-fold with whatever state we encounter and only then fold the nohz remainder and play catch-up. Reported-by: NDoug Smythies <dsmythies@telus.net> Reported-by: NLesÅ=82aw Kope=C4=87 <leslaw.kopec@nasza-klasa.pl> Reported-by: NAman Gupta <aman@tmm1.net> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-4v31etnhgg9kwd6ocgx3rxl8@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Peter Zijlstra 提交于
Suggested-by: NJoe Perches <joe@perches.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1331056466.11248.327.camel@twinsSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Peter Zijlstra 提交于
There's a few awkward printk()s inside of scheduler guts that people prefer to keep but really are rather deadlock prone. Fudge around it by storing the text in a per-cpu buffer and poll it using the existing printk_tick() handler. This will drop output when its more frequent than once a tick, however only the affinity thing could possible go that fast and for that just one should suffice to notify the admin he's done something silly.. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-wua3lmkt3dg8nfts66o6brne@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Diwakar Tundlam 提交于
The 'next_balance' field of 'nohz' idle balancer must be initialized to jiffies. Since jiffies is initialized to negative 300 seconds the 'nohz' idle balancer does not run for the first 300s (5mins) after bootup. If no new processes are spawed or no idle cycles happen, the load on the cpus will remain unbalanced for that duration. Signed-off-by: NDiwakar Tundlam <dtundlam@nvidia.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1DD7BFEDD3147247B1355BEFEFE4665237994F30EF@HQMAIL04.nvidia.comSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Peter Zijlstra 提交于
Stepan found: CPU0 CPUn _cpu_up() __cpu_up() boostrap() notify_cpu_starting() set_cpu_online() while (!cpu_active()) cpu_relax() <PREEMPT-out> smp_call_function(.wait=1) /* we find cpu_online() is true */ arch_send_call_function_ipi_mask() /* wait-forever-more */ <PREEMPT-in> local_irq_enable() cpu_notify(CPU_ONLINE) sched_cpu_active() set_cpu_active() Now the purpose of cpu_active is mostly with bringing down a cpu, where we mark it !active to avoid the load-balancer from moving tasks to it while we tear down the cpu. This is required because we only update the sched_domain tree after we brought the cpu-down. And this is needed so that some tasks can still run while we bring it down, we just don't want new tasks to appear. On cpu-up however the sched_domain tree doesn't yet include the new cpu, so its invisible to the load-balancer, regardless of the active state. So instead of setting the active state after we boot the new cpu (and consequently having to wait for it before enabling interrupts) set the cpu active before we set it online and avoid the whole mess. Reported-by: NStepan Moskovchenko <stepanm@codeaurora.org> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: NThomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1323965362.18942.71.camel@twinsSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Peter Zijlstra 提交于
Commit 367456c7 ("sched: Ditch per cgroup task lists for load-balancing") completely wrecked load-balancing due to a few silly mistakes. Correct those and remove more pointless code. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-zk04ihygwxn7qqrlpaf73b0r@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
- 08 3月, 2012 1 次提交
-
-
由 Linus Torvalds 提交于
This reverts commit 8f2f748b. It causes some odd regression that we have not figured out, and it's too late in the -rc series to try to figure it out now. As reported by Konstantin Khlebnikov, it causes consistent hangs on his laptop (Thinkpad x220: 2x cores + HT). They can be avoided by adding calls to "rebuild_sched_domains();" in cpuset_cpu_[in]active() for the CPU_{ONLINE/DOWN_FAILED/DOWN_PREPARE}_FROZEN cases, but it's not at all clear why, and it makes no sense. Konstantin's config doesn't even have CONFIG_CPUSETS enabled, just to make things even more interesting. So it's not the cpusets, it's just the scheduling domains. So until this is understood, revert. Bisected-reported-and-tested-by: NKonstantin Khlebnikov <khlebnikov@openvz.org> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: NIngo Molnar <mingo@elte.hu> Acked-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 02 3月, 2012 1 次提交
-
-
由 Hiroshi Shimamoto 提交于
Pass nice as a value to proc_sched_autogroup_set_nice(). No side effect is expected, and the variable err will be overwritten with the return value. Signed-off-by: NHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4F45FBB7.5090607@ct.jp.nec.comSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
- 01 3月, 2012 10 次提交
-
-
由 Peter Zijlstra 提交于
Per cgroup load-balance has numerous problems, chief amongst them that there is no real sane order in them. So stop pretending it makes sense and enqueue all tasks on a single list. This also allows us to more easily fix the fwd progress issue uncovered by the lock-break stuff. Rotate the list on failure to migreate and limit the total iterations to nr_running (which with releasing the lock isn't strictly accurate but close enough). Also add a filter that skips very light tasks on the first attempt around the list, this attempts to avoid shooting whole cgroups around without affecting over balance. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: pjt@google.com Link: http://lkml.kernel.org/n/tip-tx8yqydc7eimgq7i4rkc3a4g@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Peter Zijlstra 提交于
s/env->this_/env->dst_/g s/env->busiest_/env->src_/g s/pull_task/move_task/g Makes everything clearer. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: pjt@google.com Link: http://lkml.kernel.org/n/tip-0yvgms8t8x962drpvl0fu0kk@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Peter Zijlstra 提交于
Passing large sets of similar arguments all around the load-balancer gets tiresom when you want to modify something. Stick them all in a helper structure and pass the structure around. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: pjt@google.com Link: http://lkml.kernel.org/n/tip-5slqz0vhsdzewrfk9eza1aon@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Thomas Gleixner 提交于
When we are PI-blocked then we want to get things done ASAP. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-vw8et3445km5b8mpihf4trae@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Thomas Gleixner 提交于
Idle task boosting is a nono in general. There is one exception, when PREEMPT_RT and NOHZ is active: The idle task calls get_next_timer_interrupt() and holds the timer wheel base->lock on the CPU and another CPU wants to access the timer (probably to cancel it). We can safely ignore the boosting request, as the idle CPU runs this code with interrupts disabled and will complete the lock protected section without being interrupted. So there is no real need to boost. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-755rvsosz7sdzot12a3gbha6@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Thomas Gleixner 提交于
For code which protects the waitqueue itself with another lock it makes no sense to acquire the waitqueue lock for wakeup all. Provide __wake_up_all_locked(). This is an optimization on the vanilla kernel (to be used by the PCI code) and an important semantic distinction on -rt. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-ux6m4b8jonb9inx8xafh77ds@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Thomas Gleixner 提交于
Create a distinction between scheduler related preempt_enable_no_resched() calls and the nearly one hundred other places in the kernel that do not want to reschedule, for one reason or another. This distinction matters for -rt, where the scheduler and the non-scheduler preempt models (and checks) are different. For upstream it's purely documentational. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/n/tip-gs88fvx2mdv5psnzxnv575ke@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Thomas Gleixner 提交于
Add helper to get rid of the ever repeating: preempt_enable_no_resched(); schedule(); preempt_disable(); patterns. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-wxx7btox7coby6ifv5vzhzgp@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Peter Zijlstra 提交于
When a runqueue has rt_runtime_us = 0 then the only way it can accumulate rt_time is via PI boosting. That causes the runqueue to be throttled and replenishing does not change anything due to rt_runtime_us = 0. So avoid that situation by clearing rt_time and skip the throttling alltogether. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> [ Changelog ] Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/n/tip-7x70cypsotjb4jvcor3edctk@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Peter Zijlstra 提交于
When a runqueue is throttled we cannot disable the period timer because that timer is the only way to undo the throttling. We got stale throttling entries when a rq was throttled and then the global sysctl was disabled, which stopped the timer. Signed-off-by: NPeter Zijlstra <peterz@infradead.org> [ Added changelog ] Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/n/tip-nuj34q52p6ro7szapuz84i0v@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
- 27 2月, 2012 1 次提交
-
-
由 Srivatsa S. Bhat 提交于
Currently, during CPU hotplug, the cpuset callbacks modify the cpusets to reflect the state of the system, and this handling is asymmetric. That is, upon CPU offline, that CPU is removed from all cpusets. However when it comes back online, it is put back only to the root cpuset. This gives rise to a significant problem during suspend/resume. During suspend, we offline all non-boot cpus and during resume we online them back. Which means, after a resume, all cpusets (except the root cpuset) will be restricted to just one single CPU (the boot cpu). But the whole point of suspend/resume is to restore the system to a state which is as close as possible to how it was before suspend. So to fix this, don't touch cpusets during suspend/resume. That is, modify the cpuset-related CPU hotplug callback to just ignore CPU hotplug when it is initiated as part of the suspend/resume sequence. Reported-by: NPrashanth Nageshappa <prashanth@linux.vnet.ibm.com> Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/4F460D7B.1020703@linux.vnet.ibm.comSigned-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
-
- 24 2月, 2012 1 次提交
-
-
由 Ingo Molnar 提交于
static keys: Introduce 'struct static_key', static_key_true()/false() and static_key_slow_[inc|dec]() So here's a boot tested patch on top of Jason's series that does all the cleanups I talked about and turns jump labels into a more intuitive to use facility. It should also address the various misconceptions and confusions that surround jump labels. Typical usage scenarios: #include <linux/static_key.h> struct static_key key = STATIC_KEY_INIT_TRUE; if (static_key_false(&key)) do unlikely code else do likely code Or: if (static_key_true(&key)) do likely code else do unlikely code The static key is modified via: static_key_slow_inc(&key); ... static_key_slow_dec(&key); The 'slow' prefix makes it abundantly clear that this is an expensive operation. I've updated all in-kernel code to use this everywhere. Note that I (intentionally) have not pushed through the rename blindly through to the lowest levels: the actual jump-label patching arch facility should be named like that, so we want to decouple jump labels from the static-key facility a bit. On non-jump-label enabled architectures static keys default to likely()/unlikely() branches. Signed-off-by: NIngo Molnar <mingo@elte.hu> Acked-by: NJason Baron <jbaron@redhat.com> Acked-by: NSteven Rostedt <rostedt@goodmis.org> Cc: a.p.zijlstra@chello.nl Cc: mathieu.desnoyers@efficios.com Cc: davem@davemloft.net Cc: ddaney.cavm@gmail.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20120222085809.GA26397@elte.huSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
- 22 2月, 2012 3 次提交
-
-
由 Hiroshi Shimamoto 提交于
Current the initial SCHED_RR timeslice of init_task is HZ, which means 1s, and is not same as the default SCHED_RR timeslice DEF_TIMESLICE. Change that initial timeslice to the DEF_TIMESLICE. Signed-off-by: NHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> [ s/DEF_TIMESLICE/RR_TIMESLICE/g ] Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4F3C9995.3010800@ct.jp.nec.comSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Nikunj A. Dadhania 提交于
select_idle_sibling() is called from select_task_rq_fair(), which already has the RCU read lock held. Signed-off-by: NNikunj A. Dadhania <nikunj@linux.vnet.ibm.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20120217030409.11748.12491.stgit@abhimanyuSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Peter Zijlstra 提交于
Commit 1ac9bc69 ("sched/tracing: Add a new tracepoint for sleeptime") added a new sched:sched_stat_sleeptime tracepoint. It's broken: the first sample we get on a task might be bad because of a stale sleep_start value that wasn't reset at the last task switch because the tracepoint was not active. It also breaks the existing schedstat samples due to the side effects of: - se->statistics.sleep_start = 0; ... - se->statistics.block_start = 0; Nor do I see means to fix it without adding overhead to the scheduler fast path, which I'm not willing to for the sake of redundant instrumentation. Most importantly, sleep time information can already be constructed by tracing context switches and wakeups, and taking the timestamp difference between the schedule-out, the wakeup and the schedule-in. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Andrew Vagin <avagin@openvz.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/n/tip-pc4c9qhl8q6vg3bs4j6k0rbd@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
- 14 2月, 2012 1 次提交
-
-
由 Al Viro 提交于
Trim security.h Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk> Signed-off-by: NJames Morris <jmorris@namei.org>
-
- 03 2月, 2012 1 次提交
-
-
由 Li Zefan 提交于
The argument is not used at all, and it's not necessary, because a specific callback handler of course knows which subsys it belongs to. Now only ->pupulate() takes this argument, because the handlers of this callback always call cgroup_add_file()/cgroup_add_files(). So we reduce a few lines of code, though the shrinking of object size is minimal. 16 files changed, 113 insertions(+), 162 deletions(-) text data bss dec hex filename 5486240 656987 7039960 13183187 c928d3 vmlinux.o.orig 5486170 656987 7039960 13183117 c9288d vmlinux.o Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com> Signed-off-by: NTejun Heo <tj@kernel.org>
-
- 31 1月, 2012 1 次提交
-
-
由 Hiroshi Shimamoto 提交于
This also fixes the following compilation warning on !SMP: CC kernel/sched/fair.o kernel/sched/fair.c:218:36: warning: 'max_load_balance_interval' defined but not used [-Wunused-variable] Signed-off-by: NHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Reviewed-by: NVincent Guittot <vincent.guittot@linaro.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4F2754A0.9090306@ct.jp.nec.comSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
- 27 1月, 2012 6 次提交
-
-
由 Rakib Mullick 提交于
Currently we don't utilize the sched_switch field anymore. But, simply removing sched_switch field from the middle of the sched_stat output will break tools. So, to stay compatible we hardcode it to zero and remove the field from the scheduler data structures. Update the schedstat documentation accordingly. Signed-off-by: NRakib Mullick <rakib.mullick@gmail.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1327422836.27181.5.camel@localhost.localdomainSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Vincent Guittot 提交于
With a lot of small tasks, the softirq sched is nearly never called when no_hz is enabled. In this case load_balance() is mainly called with the newly_idle mode which doesn't update the cpu_power. Add a next_update field which ensure a maximum update period when there is short activity. Having stale cpu_power information can skew the load-balancing decisions, this is cured by the guaranteed update. Signed-off-by: NVincent Guittot <vincent.guittot@linaro.org> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1323717668-2143-1-git-send-email-vincent.guittot@linaro.org
-
由 Peter Zijlstra 提交于
The block layer has some code trying to determine if two CPUs share a cache, the scheduler has a similar function. Expose the function used by the scheduler and make the block layer use it, thereby removing the block layers usage of CONFIG_SCHED* and topology bits. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: NJens Axboe <axboe@kernel.dk> Link: http://lkml.kernel.org/r/1327579450.2446.95.camel@twins
-
由 Chanho Min 提交于
This issue happens under the following conditions: 1. preemption is off 2. __ARCH_WANT_INTERRUPTS_ON_CTXSW is defined 3. RT scheduling class 4. SMP system Sequence is as follows: 1.suppose current task is A. start schedule() 2.task A is enqueued pushable task at the entry of schedule() __schedule prev = rq->curr; ... put_prev_task put_prev_task_rt enqueue_pushable_task 4.pick the task B as next task. next = pick_next_task(rq); 3.rq->curr set to task B and context_switch is started. rq->curr = next; 4.At the entry of context_swtich, release this cpu's rq->lock. context_switch prepare_task_switch prepare_lock_switch raw_spin_unlock_irq(&rq->lock); 5.Shortly after rq->lock is released, interrupt is occurred and start IRQ context 6.try_to_wake_up() which called by ISR acquires rq->lock try_to_wake_up ttwu_remote rq = __task_rq_lock(p) ttwu_do_wakeup(rq, p, wake_flags); task_woken_rt 7.push_rt_task picks the task A which is enqueued before. task_woken_rt push_rt_tasks(rq) next_task = pick_next_pushable_task(rq) 8.At find_lock_lowest_rq(), If double_lock_balance() returns 0, lowest_rq can be the remote rq. (But,If preemption is on, double_lock_balance always return 1 and it does't happen.) push_rt_task find_lock_lowest_rq if (double_lock_balance(rq, lowest_rq)).. 9.find_lock_lowest_rq return the available rq. task A is migrated to the remote cpu/rq. push_rt_task ... deactivate_task(rq, next_task, 0); set_task_cpu(next_task, lowest_rq->cpu); activate_task(lowest_rq, next_task, 0); 10. But, task A is on irq context at this cpu. So, task A is scheduled by two cpus at the same time until restore from IRQ. Task A's stack is corrupted. To fix it, don't migrate an RT task if it's still running. Signed-off-by: NChanho Min <chanho.min@lge.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: NSteven Rostedt <rostedt@goodmis.org> Cc: <stable@kernel.org> Link: http://lkml.kernel.org/r/CAOAMb1BHA=5fm7KTewYyke6u-8DP0iUuJMpgQw54vNeXFsGpoQ@mail.gmail.comSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Suresh Siddha 提交于
With the recent nohz scheduler changes, rq's nohz flag 'NOHZ_TICK_STOPPED' and its associated state doesn't get cleared immediately after the cpu exits idle. This gets cleared as part of the next tick seen on that cpu. For the cpu offline support, we need to clear this state manually. Fix it by registering a cpu notifier, which clears the nohz idle load balance state for this rq explicitly during the CPU_DYING notification. There won't be any nohz updates for that cpu, after the CPU_DYING notification. But lets be extra paranoid and skip updating the nohz state in the select_nohz_load_balancer() if the cpu is not in active state anymore. Reported-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Reviewed-and-tested-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Tested-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1327026538.16150.40.camel@sbsiddha-desk.sc.intel.comSigned-off-by: NIngo Molnar <mingo@elte.hu>
-
由 Christian Borntraeger 提交于
Commit 029632fb ("sched: Make separate sched*.c translation units") removed the include of asm/mutex.h from sched.c. This breaks the combination of: CONFIG_MUTEX_SPIN_ON_OWNER=yes CONFIG_HAVE_ARCH_MUTEX_CPU_RELAX=yes like s390 without mutex debugging: CC kernel/sched/core.o kernel/sched/core.c: In function ‘mutex_spin_on_owner’: kernel/sched/core.c:3287: error: implicit declaration of function ‘arch_mutex_cpu_relax’ Lets re-add the include to kernel/sched/core.c Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1326268696-30904-1-git-send-email-borntraeger@de.ibm.comSigned-off-by: NIngo Molnar <mingo@elte.hu>
-