- 28 Feb, 2014 2 commits
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Ingo Molnar authored
Avoid heavy conflicts caused by WIP patches in drivers/cpuidle/cpuidle.c, by merging these into a single base. Signed-off-by:Ingo Molnar <mingo@kernel.org>
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Thomas Gleixner authored
Merge branch 'timers.2014.02.25a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into timers/core Signed-off-by:
Thomas Gleixner <tglx@linutronix.de>
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- 27 Feb, 2014 4 commits
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Dongsheng Yang authored
Use MAX_NICE instead of the value 19 for ring_buffer_benchmark. Signed-off-by:
Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Signed-off-by:
Peter Zijlstra <peterz@infradead.org> Acked-by:
Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/1393251121-25534-1-git-send-email-yangds.fnst@cn.fujitsu.comSigned-off-by:
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Peter Zijlstra authored
Michael spotted that the idle_balance() push down created a task priority problem. Previously, when we called idle_balance() before pick_next_task() it wasn't a problem when -- because of the rq->lock droppage -- an rt/dl task slipped in. Similarly for pre_schedule(), rt pre-schedule could have a dl task slip in. But by pulling it into the pick_next_task() loop, we'll not try a higher task priority again. Cure this by creating a re-start condition in pick_next_task(); and triggering this from pick_next_task_{rt,fair}(). It also fixes a live-lock where we get stuck in pick_next_task_fair() due to idle_balance() seeing !0 nr_running but there not actually being any fair tasks about. Reported-by:Michael Wang <wangyun@linux.vnet.ibm.com> Fixes: 38033c37 ("sched: Push down pre_schedule() and idle_balance()") Tested-by:
Sasha Levin <sasha.levin@oracle.com> Signed-off-by:
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Peter Zijlstra authored
Commit cf37b6b4 ("sched/idle: Move cpu/idle.c to sched/idle.c") said to simply move a file; somehow it got mangled and created an old version of the file and forgot to remove the old file. Fix this fail; add the lost change and remove the now identical old file. Signed-off-by:
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Dietmar Eggemann authored
The struct sched_avg of struct rq is only used in case group scheduling is enabled inside __update_tg_runnable_avg() to update per-cpu representation of a task group. I.e. that there is no need to maintain the runnable avg of a rq in the !CONFIG_FAIR_GROUP_SCHED case. This patch guards struct sched_avg of struct rq and update_rq_runnable_avg() with CONFIG_FAIR_GROUP_SCHED. There is an extra empty definition for update_rq_runnable_avg() necessary for the !CONFIG_FAIR_GROUP_SCHED && CONFIG_SMP case. The function print_cfs_group_stats() which prints out struct sched_avg of struct rq is already guarded with CONFIG_FAIR_GROUP_SCHED. Reviewed-by:
Ben Segall <bsegall@google.com> Signed-off-by:
Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by:
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- 25 Feb, 2014 5 commits
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Oleg Nesterov authored
The internal_add_timer() function updates base->next_timer only if timer->expires < base->next_timer. This is correct, but it also makes sense to do the same if we add the first non-deferrable timer. Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Reviewed-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by:
Josh Triplett <josh@joshtriplett.org> Acked-by:
Mike Galbraith <bitbucket@online.de>
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Paul E. McKenney authored
The __run_timers() function currently steps through the list one jiffy at a time in order to update the timer wheel. However, if the timer wheel is empty, no adjustment is needed other than updating ->timer_jiffies. Therefore, just before we add a timer to an empty timer wheel, we should mark the timer wheel as being up to date. This marking will reduce (and perhaps eliminate) the jiffy-stepping that a future __run_timers() call will need to do in response to some future timer posting or migration. This commit therefore updates ->timer_jiffies for this case. Signed-off-by:
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Paul E. McKenney authored
The __run_timers() function currently steps through the list one jiffy at a time in order to update the timer wheel. However, if the timer wheel is empty, no adjustment is needed other than updating ->timer_jiffies. Therefore, if we just emptied the timer wheel, for example, by deleting the last timer, we should mark the timer wheel as being up to date. This marking will reduce (and perhaps eliminate) the jiffy-stepping that a future __run_timers() call will need to do in response to some future timer posting or migration. This commit therefore catches ->timer_jiffies for this case. Signed-off-by:
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Paul E. McKenney authored
The __run_timers() function currently steps through the list one jiffy at a time in order to update the timer wheel. However, if the timer wheel is empty, no adjustment is needed other than updating ->timer_jiffies. In this case, which is likely to be common for NO_HZ_FULL kernels, the kernel currently incurs a large latency for no good reason. This commit therefore short-circuits this case. Signed-off-by:
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Paul E. McKenney authored
Currently, the tvec_base structure's ->active_timers field tracks only the non-deferrable timers, which means that even if ->active_timers is zero, there might well be deferrable timers in the list. This commit therefore adds an ->all_timers field to track all the timers, whether deferrable or not. Signed-off-by:
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- 22 Feb, 2014 18 commits
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Nicolas Pitre authored
The core idle loop now takes care of it. Signed-off-by:
Nicolas Pitre <nico@linaro.org> Acked-by:
Catalin Marinas <catalin.marinas@arm.com> Signed-off-by:
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Nicolas Pitre authored
The core idle loop now takes care of it. We need to add the runlatch function calls to the idle routines which was earlier taken care of by the arch specific idle routine. Signed-off-by:
Preeti U Murthy <preeti@linux.vnet.ibm.com> Reviewed-by:
Deepthi Dharwar <deepthi@linux.vnet.ibm.com> Signed-off-by:
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Mike Galbraith authored
The user explicitly disabled load balancing, else this core would not be disconnected. Don't add these to nohz.idle_cpus_mask. Signed-off-by:
Mike Galbraith <mgalbraith@suse.de> Signed-off-by:
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Morten Rasmussen authored
Brings select_task_rq_fair() description comments up-to-date. Signed-off-by:
Morten Rasmussen <morten.rasmussen@arm.com> Signed-off-by:
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Dongsheng Yang authored
Signed-off-by:
Tejun Heo <tj@kernel.org> Signed-off-by:
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Dongsheng Yang authored
Signed-off-by:
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Dongsheng Yang authored
Signed-off-by:
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Dongsheng Yang authored
Reviewed-by:
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Dongsheng Yang authored
Currently there is lots of hard coding to 19 and -20, to represent maximum and minimum of nice values. This patch add three macros in prio.h for maximum, minimum and width of nice value, and uses it to remove hardcoded values in prio.h. Signed-off-by:
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Dongsheng Yang authored
There is already a macro named DEFAULT_PRIO in prio.h, we can use it to define NICE_TO_PRIO and PRIO_TO_NICE rather than use hard coding of (MAX_RT_PRIO + 20). Signed-off-by:
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Li Zefan authored
It's a bootstrap function. Signed-off-by:
Li Zefan <lizefan@huawei.com> Signed-off-by:
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Li Zefan authored
This is a leftover from commit e23ee747 ("sched/rt: Simplify pull_rt_task() logic and remove .leaf_rt_rq_list"). Signed-off-by:
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Thomas Gleixner authored
If a PI boosted task policy/priority is modified by a setscheduler() call we unconditionally dequeue and requeue the task if it is on the runqueue even if the new priority is lower than the current effective boosted priority. This can result in undesired reordering of the priority bucket list. If the new priority is less or equal than the current effective we just store the new parameters in the task struct and leave the scheduler class and the runqueue untouched. This is handled when the task deboosts itself. Only if the new priority is higher than the effective boosted priority we apply the change immediately. Signed-off-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Dario Faggioli <raistlin@linux.it> Signed-off-by:
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Thomas Gleixner authored
The following scenario does not work correctly: Runqueue of CPUx contains two runnable and pinned tasks: T1: SCHED_FIFO, prio 80 T2: SCHED_FIFO, prio 80 T1 is on the cpu and executes the following syscalls (classic priority ceiling scenario): sys_sched_setscheduler(pid(T1), SCHED_FIFO, .prio = 90); ... sys_sched_setscheduler(pid(T1), SCHED_FIFO, .prio = 80); ... Now T1 gets preempted by T3 (SCHED_FIFO, prio 95). After T3 goes back to sleep the scheduler picks T2. Surprise! The same happens w/o actual preemption when T1 is forced into the scheduler due to a sporadic NEED_RESCHED event. The scheduler invokes pick_next_task() which returns T2. So T1 gets preempted and scheduled out. This happens because sched_setscheduler() dequeues T1 from the prio 90 list and then enqueues it on the tail of the prio 80 list behind T2. This violates the POSIX spec and surprises user space which relies on the guarantee that SCHED_FIFO tasks are not scheduled out unless they give the CPU up voluntarily or are preempted by a higher priority task. In the latter case the preempted task must get back on the CPU after the preempting task schedules out again. We fixed a similar issue already in commit 60db48ca (sched: Queue a deboosted task to the head of the RT prio queue). The same treatment is necessary for sched_setscheduler(). So enqueue to head of the prio bucket list if the priority of the task is lowered. It might be possible that existing user space relies on the current behaviour, but it can be considered highly unlikely due to the corner case nature of the application scenario. Signed-off-by:
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Thomas Gleixner authored
If the policy and priority remain unchanged a possible modification of p->sched_reset_on_fork gets lost in the early exit path. Signed-off-by:
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Thomas Gleixner authored
might_sleep() can tell us where interrupts have been disabled, but we have no idea what disabled preemption. Add some debug infrastructure. Signed-off-by:
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Thomas Gleixner authored
Idle is not allowed to call sleeping functions ever! Signed-off-by:
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Thomas Gleixner authored
We stumbled in RT over a SMP bringup issue on ARM where the idle->on_rq == 0 was causing try_to_wakeup() on the other cpu to run into nada land. After adding that idle->on_rq = 1; I was able to find the root cause of the lockup: the idle task on the newly woken up cpu was fiddling with a sleeping spinlock, which is a nono. I kept the init of idle->on_rq to keep the state consistent and to avoid another long lasting debug session. As a side note, the whole debug mess could have been avoided if might_sleep() would have yelled when called from the idle task. That's fixed with patch 2/6 - and that one actually has a changelog :) Signed-off-by:
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- 21 Feb, 2014 5 commits
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Peter Zijlstra authored
Remove a few gratuitous #ifdefs in pick_next_task*(). Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Juri Lelli <juri.lelli@gmail.com> Signed-off-by:
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Peter Zijlstra authored
Dan Carpenter reported: > kernel/sched/rt.c:1347 pick_next_task_rt() warn: variable dereferenced before check 'prev' (see line 1338) > kernel/sched/deadline.c:1011 pick_next_task_dl() warn: variable dereferenced before check 'prev' (see line 1005) Kirill also spotted that migrate_tasks() will have an instant NULL deref because pick_next_task() will immediately deref prev. Instead of fixing all the corner cases because migrate_tasks() can pass in a NULL prev task in the unlikely case of hot-un-plug, provide a fake task such that we can remove all the NULL checks from the far more common paths. A further problem; not previously spotted; is that because we pushed pre_schedule() and idle_balance() into pick_next_task() we now need to avoid those getting called and pulling more tasks on our dying CPU. We avoid pull_{dl,rt}_task() by setting fake_task.prio to MAX_PRIO+1. We also note that since we call pick_next_task() exactly the amount of times we have runnable tasks present, we should never land in idle_balance(). Fixes: 38033c37 ("sched: Push down pre_schedule() and idle_balance()") Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Reported-by:Kirill Tkhai <tkhai@yandex.ru> Reported-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
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Peter Zijlstra authored
Remove idle_balance() from the public life; also reduce some #ifdef clutter by folding the pick_next_task_fair() idle path into idle_balance(). Cc: mingo@kernel.org Reported-by:
Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by:
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Michael wang authored
Sasha reported: [ 522.645288] BUG: unable to handle kernel NULL pointer dereference at ... [ 522.646271] IP: [<ffffffff81186c6f>] check_preempt_wakeup+0x11f/0x210 ... [ 522.650021] Call Trace: [ 522.650021] <IRQ> [ 522.650021] [<ffffffff8117361d>] check_preempt_curr+0x3d/0xb0 [ 522.650021] [<ffffffff81175d88>] ttwu_do_wakeup+0x18/0x130 ... which was caused by the se-depth changed during the time when task is not FAIR, and we will use the wrong depth value after it switched back to FAIR. This patch reset the depth at the time when task switched to FAIR, make sure that we always have the correct value when task is FAIR. Cc: Ingo Molnar <mingo@kernel.org> Reported-by:
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Thomas Gleixner authored
Reason: Bring bakc upstream modification to resolve conflicts Signed-off-by:
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- 20 Feb, 2014 6 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pciLinus Torvalds authored
Pull PCI updates from Bjorn Helgaas: "The most interesting thing here is the change to enable INTx (by clearing PCI_COMMAND_INTX_DISABLE) if the BIOS left INTx disabled. Apparently the Baytrail BIOS does this, which means EHCI doesn't work. Also, fix an AHCI MSI regression and other issues with the recent MSI changes. This also adds pci_enable_msi_exact() and pci_enable_msix_exact(), which aren't regression fixes, but will keep us from touching drivers twice (once to stop using the deprecated pci_enable_msi(), etc., and again to use the *_exact() variants). There's also a minor MVEBU fix. Summary: MSI: - Fix AHCI single-MSI fallback (Alexander Gordeev) - Fix populate_msi_sysfs() error paths (Greg Kroah-Hartman) - Fix htmldocs problem (Masanari Iida) - Add pci_enable_msi_exact() and pci_enable_msix_exact() (Alexander Gordeev) - Update documentation (Alexander Gordeev) Miscellaneous: - mvebu: expose device ID & revision via lspci (Andrew Lunn) - Enable INTx if the BIOS left them disabled (Bjorn Helgaas)" * tag 'pci-v3.14-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: ahci: Fix broken fallback to single MSI mode PCI: Enable INTx if BIOS left them disabled PCI/MSI: Add pci_enable_msi_exact() and pci_enable_msix_exact() PCI/MSI: Fix cut-and-paste errors in documentation PCI/MSI: Add pci_enable_msi() documentation back PCI/MSI: Fix pci_msix_vec_count() htmldocs failure PCI/MSI: Fix leak of msi_attrs PCI/MSI: Check kmalloc() return value, fix leak of name PCI: mvebu: Use Device ID and revision from underlying endpoint -
git://git.kernel.org/pub/scm/linux/kernel/git/tj/libataLinus Torvalds authored
Pull libata fixes from Tejun Heo: "Various device specific fixes. Nothing too interesting" * 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata: ahci: disable NCQ on Samsung pci-e SSDs on macbooks ata: sata_mv: Cleanup only the initialized ports sata_sil: apply MOD15WRITE quirk to TOSHIBA MK2561GSYN ata: enable quirk from jmicron JMB350 for JMB394 ATA: SATA_MV: Add missing Kconfig select statememnt ata: pata_imx: Check the return value from clk_prepare_enable()
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroupLinus Torvalds authored
Pull cgroup fixes from Tejun Heo: "Quite a few fixes this time. Three locking fixes, all marked for -stable. A couple error path fixes and some misc fixes. Hugh found a bug in memcg offlining sequence and we thought we could fix that from cgroup core side but that turned out to be insufficient and got reverted. A different fix has been applied to -mm" * 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: update cgroup_enable_task_cg_lists() to grab siglock Revert "cgroup: use an ordered workqueue for cgroup destruction" cgroup: protect modifications to cgroup_idr with cgroup_mutex cgroup: fix locking in cgroup_cfts_commit() cgroup: fix error return from cgroup_create() cgroup: fix error return value in cgroup_mount() cgroup: use an ordered workqueue for cgroup destruction nfs: include xattr.h from fs/nfs/nfs3proc.c cpuset: update MAINTAINERS entry arm, pm, vmpressure: add missing slab.h includes
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds authored
Pull workqueue fixes from Tejun Heo: "Two workqueue fixes. One for an unlikely but possible critical bug during kworker shutdown and the other to make lockdep names a bit more descriptive" * 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: ensure @task is valid across kthread_stop() workqueue: add args to workqueue lockdep name
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git://git.linaro.org/people/mszyprowski/linux-dma-mappingLinus Torvalds authored
Pull DMA-mapping fixes from Marek Szyprowski: "This contains fixes for incorrect atomic test in dma-mapping subsystem for ARM and x86 architecture" * 'fixes-for-v3.14' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping: x86: dma-mapping: fix GFP_ATOMIC macro usage ARM: dma-mapping: fix GFP_ATOMIC macro usage
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Brian Campbell authored
Signed-off-by:
Brian Campbell <brian.campbell@editshare.com> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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