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2015-05-19clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED stateViresh Kumar
When no timers/hrtimers are pending, the expiry time is set to a special value: 'KTIME_MAX'. This normally happens with NO_HZ_{IDLE|FULL} in both LOWRES/HIGHRES modes. When 'expiry == KTIME_MAX', we either cancel the 'tick-sched' hrtimer (NOHZ_MODE_HIGHRES) or skip reprogramming clockevent device (NOHZ_MODE_LOWRES). But, the clockevent device is already reprogrammed from the tick-handler for next tick. As the clock event device is programmed in ONESHOT mode it will at least fire one more time (unnecessarily). Timers on few implementations (like arm_arch_timer, etc.) only support PERIODIC mode and their drivers emulate ONESHOT over that. Which means that on these platforms we will get spurious interrupts periodically (at last programmed interval rate, normally tick rate). In order to avoid spurious interrupts, the clockevent device should be stopped or its interrupts should be masked. A simple (yet hacky) solution to get this fixed could be: update hrtimer_force_reprogram() to always reprogram clockevent device and update clockevent drivers to STOP generating events (or delay it to max time) when 'expires' is set to KTIME_MAX. But the drawback here is that every clockevent driver has to be hacked for this particular case and its very easy for new ones to miss this. However, Thomas suggested to add an optional state ONESHOT_STOPPED to solve this problem: lkml.org/lkml/2014/5/9/508. This patch adds support for ONESHOT_STOPPED state in clockevents core. It will only be available to drivers that implement the state-specific callbacks instead of the legacy ->set_mode() callback. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com> Cc: linaro-kernel@lists.linaro.org Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/b8b383a03ac07b13312c16850b5106b82e4245b5.1428031396.git.viresh.kumar@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-19Merge branch 'linus' into timers/coreThomas Gleixner
Make sure the upstream fixes are applied before adding further modifications.
2015-05-19Merge branch 'irq/for-x86' into x86/apicThomas Gleixner
Pull the irq core change which is required to merge the preparatory patches for posted interrupts.
2015-05-19Merge branch 'irq/for-x86' into irq/coreThomas Gleixner
Pull in the branch which can be consumed by x86 to build their changes on top.
2015-05-19genirq: Introduce irq_set_vcpu_affinity() to target an interrupt to a VCPUJiang Liu
With Posted-Interrupts support in Intel CPU and IOMMU, an external interrupt from assigned-devices could be directly delivered to a virtual CPU in a virtual machine. Instead of hacking KVM and Intel IOMMU drivers, we propose a platform independent interface to target an interrupt to a specific virtual CPU in a virtual machine, or set virtual CPU affinity for an interrupt. By adopting this new interface and the hierarchy irqdomain, we could easily support posted-interrupts on Intel platforms, and also provide flexible enough interfaces for other platforms to support similar features. Here is the usage scenario for this interface: Guest update MSI/MSI-X interrupt configuration -->QEMU and KVM handle this -->KVM call this interface (passing posted interrupts descriptor and guest vector) -->irq core will transfer the control to IOMMU -->IOMMU will do the real work of updating IRTE (IRTE has new format for VT-d Posted-Interrupts) Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Signed-off-by: Feng Wu <feng.wu@intel.com> Link: http://lkml.kernel.org/r/1432026437-16560-2-git-send-email-feng.wu@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-19time: Refactor msecs_to_jiffiesNicholas Mc Guire
Refactor the msecs_to_jiffies conditional code part in time.c and jiffies.h putting it into conditional functions rather than #ifdefs to improve readability. [ tglx: Verified that there is no binary code change ] Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Cc: Masahiro Yamada <yamada.m@jp.panasonic.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Joe Perches <joe@perches.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Andrew Hunter <ahh@google.com> Cc: Paul Turner <pjt@google.com> Cc: Michal Marek <mmarek@suse.cz> Link: http://lkml.kernel.org/r/1431951554-5563-2-git-send-email-hofrat@osadl.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-19time: Move timeconst.h into include/generatedNicholas Mc Guire
kernel/time/timeconst.h is moved to include/generated/ and generated by the top level Kbuild. This allows using timeconst.h in an earlier build stage. Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Cc: Masahiro Yamada <yamada.m@jp.panasonic.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Joe Perches <joe@perches.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Andrew Hunter <ahh@google.com> Cc: Paul Turner <pjt@google.com> Cc: Michal Marek <mmarek@suse.cz> Link: http://lkml.kernel.org/r/1431951554-5563-1-git-send-email-hofrat@osadl.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-19sched/numa: Reduce conflict between fbq_classify_rq() and migrationRik van Riel
It is possible for fbq_classify_rq() to indicate that a CPU has tasks that should be moved to another NUMA node, but for migrate_improves_locality and migrate_degrades_locality to not identify those tasks. This patch always gives preference to preferred node evaluations, and only checks the number of faults when evaluating moves between two non-preferred nodes on a larger NUMA system. On a two node system, the number of faults is never evaluated. Either a task is about to be pulled off its preferred node, or migrated onto it. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: mgorman@suse.de Link: http://lkml.kernel.org/r/20150514225936.35b91717@annuminas.surriel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19sched/preempt, mm/fault: Count pagefault_disable() levels in pagefault_disabledDavid Hildenbrand
Until now, pagefault_disable()/pagefault_enabled() used the preempt count to track whether in an environment with pagefaults disabled (can be queried via in_atomic()). This patch introduces a separate counter in task_struct to count the level of pagefault_disable() calls. We'll keep manipulating the preempt count to retain compatibility to existing pagefault handlers. It is now possible to verify whether in a pagefault_disable() envionment by calling pagefault_disabled(). In contrast to in_atomic() it will not be influenced by preempt_enable()/preempt_disable(). This patch is based on a patch from Ingo Molnar. Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: airlied@linux.ie Cc: akpm@linux-foundation.org Cc: benh@kernel.crashing.org Cc: bigeasy@linutronix.de Cc: borntraeger@de.ibm.com Cc: daniel.vetter@intel.com Cc: heiko.carstens@de.ibm.com Cc: herbert@gondor.apana.org.au Cc: hocko@suse.cz Cc: hughd@google.com Cc: mst@redhat.com Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: schwidefsky@de.ibm.com Cc: yang.shi@windriver.com Link: http://lkml.kernel.org/r/1431359540-32227-2-git-send-email-dahi@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19sched/preempt: Optimize preemption operations on __schedule() callersFrederic Weisbecker
__schedule() disables preemption and some of its callers (the preempt_schedule*() family) also set PREEMPT_ACTIVE. So we have two preempt_count() modifications that could be performed at once. Lets remove the preemption disablement from __schedule() and pull this responsibility to its callers in order to optimize preempt_count() operations in a single place. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1431441711-29753-5-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19Merge tag 'v4.1-rc4' into sched/core, before applying new patchesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19locking/arch: Rename set_mb() to smp_store_mb()Peter Zijlstra
Since set_mb() is really about an smp_mb() -- not a IO/DMA barrier like mb() rename it to match the recent smp_load_acquire() and smp_store_release(). Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.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>
2015-05-19PM / sleep: Make suspend-to-idle-specific code depend on CONFIG_SUSPENDRafael J. Wysocki
Since idle_should_freeze() is defined to always return 'false' for CONFIG_SUSPEND unset, all of the code depending on it in cpuidle_idle_call() is not necessary in that case. Make that code depend on CONFIG_SUSPEND too to avoid building it when it is not going to be used. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-19PM / sleep: Return -EBUSY from suspend_enter() on wakeup detectionRuchi Kandoi
If a wakeup source is found to be pending in the last stage of suspend after syscore suspend, then the machine won't suspend, but suspend_enter() will return 0. That is confusing, as wakeup detection elsewhere causes -EBUSY to be returned from suspend_enter(). To avoid the confusion, make suspend_enter() return -EBUSY in that case too. Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com> [ rjw: Subject and changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-18sched: always use blk_schedule_flush_plug in io_schedule_outShaohua Li
block plug callback could sleep, so we introduce a parameter 'from_schedule' and corresponding drivers can use it to destinguish a schedule plug flush or a plug finish. Unfortunately io_schedule_out still uses blk_flush_plug(). This causes below output (Note, I added a might_sleep() in raid1_unplug to make it trigger faster, but the whole thing doesn't matter if I add might_sleep). In raid1/10, this can cause deadlock. This patch makes io_schedule_out always uses blk_schedule_flush_plug. This should only impact drivers (as far as I know, raid 1/10) which are sensitive to the 'from_schedule' parameter. [ 370.817949] ------------[ cut here ]------------ [ 370.817960] WARNING: CPU: 7 PID: 145 at ../kernel/sched/core.c:7306 __might_sleep+0x7f/0x90() [ 370.817969] do not call blocking ops when !TASK_RUNNING; state=2 set at [<ffffffff81092fcf>] prepare_to_wait+0x2f/0x90 [ 370.817971] Modules linked in: raid1 [ 370.817976] CPU: 7 PID: 145 Comm: kworker/u16:9 Tainted: G W 4.0.0+ #361 [ 370.817977] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153802- 04/01/2014 [ 370.817983] Workqueue: writeback bdi_writeback_workfn (flush-9:1) [ 370.817985] ffffffff81cd83be ffff8800ba8cb298 ffffffff819dd7af 0000000000000001 [ 370.817988] ffff8800ba8cb2e8 ffff8800ba8cb2d8 ffffffff81051afc ffff8800ba8cb2c8 [ 370.817990] ffffffffa00061a8 000000000000041e 0000000000000000 ffff8800ba8cba28 [ 370.817993] Call Trace: [ 370.817999] [<ffffffff819dd7af>] dump_stack+0x4f/0x7b [ 370.818002] [<ffffffff81051afc>] warn_slowpath_common+0x8c/0xd0 [ 370.818004] [<ffffffff81051b86>] warn_slowpath_fmt+0x46/0x50 [ 370.818006] [<ffffffff81092fcf>] ? prepare_to_wait+0x2f/0x90 [ 370.818008] [<ffffffff81092fcf>] ? prepare_to_wait+0x2f/0x90 [ 370.818010] [<ffffffff810776ef>] __might_sleep+0x7f/0x90 [ 370.818014] [<ffffffffa0000c03>] raid1_unplug+0xd3/0x170 [raid1] [ 370.818024] [<ffffffff81421d9a>] blk_flush_plug_list+0x8a/0x1e0 [ 370.818028] [<ffffffff819e3550>] ? bit_wait+0x50/0x50 [ 370.818031] [<ffffffff819e21b0>] io_schedule_timeout+0x130/0x140 [ 370.818033] [<ffffffff819e3586>] bit_wait_io+0x36/0x50 [ 370.818034] [<ffffffff819e31b5>] __wait_on_bit+0x65/0x90 [ 370.818041] [<ffffffff8125b67c>] ? ext4_read_block_bitmap_nowait+0xbc/0x630 [ 370.818043] [<ffffffff819e3550>] ? bit_wait+0x50/0x50 [ 370.818045] [<ffffffff819e3302>] out_of_line_wait_on_bit+0x72/0x80 [ 370.818047] [<ffffffff810935e0>] ? autoremove_wake_function+0x40/0x40 [ 370.818050] [<ffffffff811de744>] __wait_on_buffer+0x44/0x50 [ 370.818053] [<ffffffff8125ae80>] ext4_wait_block_bitmap+0xe0/0xf0 [ 370.818058] [<ffffffff812975d6>] ext4_mb_init_cache+0x206/0x790 [ 370.818062] [<ffffffff8114bc6c>] ? lru_cache_add+0x1c/0x50 [ 370.818064] [<ffffffff81297c7e>] ext4_mb_init_group+0x11e/0x200 [ 370.818066] [<ffffffff81298231>] ext4_mb_load_buddy+0x341/0x360 [ 370.818068] [<ffffffff8129a1a3>] ext4_mb_find_by_goal+0x93/0x2f0 [ 370.818070] [<ffffffff81295b54>] ? ext4_mb_normalize_request+0x1e4/0x5b0 [ 370.818072] [<ffffffff8129ab67>] ext4_mb_regular_allocator+0x67/0x460 [ 370.818074] [<ffffffff81295b54>] ? ext4_mb_normalize_request+0x1e4/0x5b0 [ 370.818076] [<ffffffff8129ca4b>] ext4_mb_new_blocks+0x4cb/0x620 [ 370.818079] [<ffffffff81290956>] ext4_ext_map_blocks+0x4c6/0x14d0 [ 370.818081] [<ffffffff812a4d4e>] ? ext4_es_lookup_extent+0x4e/0x290 [ 370.818085] [<ffffffff8126399d>] ext4_map_blocks+0x14d/0x4f0 [ 370.818088] [<ffffffff81266fbd>] ext4_writepages+0x76d/0xe50 [ 370.818094] [<ffffffff81149691>] do_writepages+0x21/0x50 [ 370.818097] [<ffffffff811d5c00>] __writeback_single_inode+0x60/0x490 [ 370.818099] [<ffffffff811d630a>] writeback_sb_inodes+0x2da/0x590 [ 370.818103] [<ffffffff811abf4b>] ? trylock_super+0x1b/0x50 [ 370.818105] [<ffffffff811abf4b>] ? trylock_super+0x1b/0x50 [ 370.818107] [<ffffffff811d665f>] __writeback_inodes_wb+0x9f/0xd0 [ 370.818109] [<ffffffff811d69db>] wb_writeback+0x34b/0x3c0 [ 370.818111] [<ffffffff811d70df>] bdi_writeback_workfn+0x23f/0x550 [ 370.818116] [<ffffffff8106bbd8>] process_one_work+0x1c8/0x570 [ 370.818117] [<ffffffff8106bb5b>] ? process_one_work+0x14b/0x570 [ 370.818119] [<ffffffff8106c09b>] worker_thread+0x11b/0x470 [ 370.818121] [<ffffffff8106bf80>] ? process_one_work+0x570/0x570 [ 370.818124] [<ffffffff81071868>] kthread+0xf8/0x110 [ 370.818126] [<ffffffff81071770>] ? kthread_create_on_node+0x210/0x210 [ 370.818129] [<ffffffff819e9322>] ret_from_fork+0x42/0x70 [ 370.818131] [<ffffffff81071770>] ? kthread_create_on_node+0x210/0x210 [ 370.818132] ---[ end trace 7b4deb71e68b6605 ]--- V2: don't change ->in_iowait Cc: NeilBrown <neilb@suse.de> Signed-off-by: Shaohua Li <shli@fb.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-18Merge branch 'irq/for-arm' into irq/coreThomas Gleixner
Pull in the branch which can be consumed by ARM to build their changes on top.
2015-05-18cgroup: switch to unsigned long for bitmasksAleksa Sarai
Switch the type of all internal cgroup masks to (unsigned long), which is the correct type for bitmasks. This is in preparation for the for_each_subsys_which patch. Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-05-18workqueue: simplify wq_update_unbound_numa()Lai Jiangshan
wq_update_unbound_numa() is known be called with wq_pool_mutex held. But wq_update_unbound_numa() requests wq->mutex before reading wq->unbound_attrs, wq->numa_pwq_tbl[] and wq->dfl_pwq. But these fields were changed to be allowed being read with wq_pool_mutex held. So we simply remove the mutex_lock(&wq->mutex). Without the dependence on the the mutex_lock(&wq->mutex), the test of wq->unbound_attrs->no_numa can also be moved upward. The old code need a long comment to describe the stableness of @wq->unbound_attrs which is also guaranteed by wq_pool_mutex now, so we don't need this such comment. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-05-18workqueue: wq_pool_mutex protects the attrs-installationLai Jiangshan
Current wq_pool_mutex doesn't proctect the attrs-installation, it results that ->unbound_attrs, ->numa_pwq_tbl[] and ->dfl_pwq can only be accessed under wq->mutex and causes some inconveniences. Example, wq_update_unbound_numa() has to acquire wq->mutex before fetching the wq->unbound_attrs->no_numa and the old_pwq. attrs-installation is a short operation, so this change will no cause any latency for other operations which also acquire the wq_pool_mutex. The only unprotected attrs-installation code is in apply_workqueue_attrs(), so this patch touches code less than comments. It is also a preparation patch for next several patches which read wq->unbound_attrs, wq->numa_pwq_tbl[] and wq->dfl_pwq with only wq_pool_mutex held. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-05-18watchdog: Fix merge 'conflict'Peter Zijlstra
Two watchdog changes that came through different trees had a non conflicting conflict, that is, one changed the semantics of a variable but no actual code conflict happened. So the merge appeared fine, but the resulting code did not behave as expected. Commit 195daf665a62 ("watchdog: enable the new user interface of the watchdog mechanism") changes the semantics of watchdog_user_enabled, which thereafter is only used by the functions introduced by b3738d293233 ("watchdog: Add watchdog enable/disable all functions"). There further appears to be a distinct lack of serialization between setting and using watchdog_enabled, so perhaps we should wrap the {en,dis}able_all() things in watchdog_proc_mutex. This patch fixes a s2r failure reported by Michal; which I cannot readily explain. But this does make the code internally consistent again. Reported-and-tested-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-18genirq: generic chip: Support hierarchy domainStefan Agner
Use the new helper function irq_domain_set_info to make sure the function irq_domain_set_hwirq_and_chip is being called, which is crucial to save irqdomain specific data to irq_data. Signed-off-by: Stefan Agner <stefan@agner.ch> Cc: marc.zyngier@arm.com Cc: linux@arm.linux.org.uk Cc: u.kleine-koenig@pengutronix.de Cc: olof@lixom.net Cc: arnd@arndb.de Cc: daniel.lezcano@linaro.org Cc: mark.rutland@arm.com Cc: pawel.moll@arm.com Cc: robh+dt@kernel.org Cc: ijc+devicetree@hellion.org.uk Cc: galak@codeaurora.org Cc: mcoquelin.stm32@gmail.com Cc: linux-arm-kernel@lists.infradead.org Cc: shawn.guo@linaro.org Cc: kernel@pengutronix.de Cc: jason@lakedaemon.net Link: http://lkml.kernel.org/r/1431769465-26867-4-git-send-email-stefan@agner.ch Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-18genirq: Add irq_chip_(enable/disable)_parentStefan Agner
Add helper irq_chip_enable_parent and irq_chip_disable_parent. The helper implement the default behavior in case irq_enable or irq_disable is not implemented for the parent interrupt chip, which is calling the irq_mask or irq_unmask respectively. Signed-off-by: Stefan Agner <stefan@agner.ch> Cc: marc.zyngier@arm.com Cc: linux@arm.linux.org.uk Cc: u.kleine-koenig@pengutronix.de Cc: olof@lixom.net Cc: arnd@arndb.de Cc: daniel.lezcano@linaro.org Cc: mark.rutland@arm.com Cc: pawel.moll@arm.com Cc: robh+dt@kernel.org Cc: ijc+devicetree@hellion.org.uk Cc: galak@codeaurora.org Cc: mcoquelin.stm32@gmail.com Cc: linux-arm-kernel@lists.infradead.org Cc: shawn.guo@linaro.org Cc: kernel@pengutronix.de Cc: jason@lakedaemon.net Link: http://lkml.kernel.org/r/1431769465-26867-3-git-send-email-stefan@agner.ch Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-18irqdomain: Add non-hierarchy helper irq_domain_set_infoStefan Agner
This adds the helper irq_domain_set_info() in a non-domain hierarchy variant. This allows to use the helper for generic chip since not all chips using generic chip support domain hierarchy. Signed-off-by: Stefan Agner <stefan@agner.ch> Cc: marc.zyngier@arm.com Cc: linux@arm.linux.org.uk Cc: u.kleine-koenig@pengutronix.de Cc: olof@lixom.net Cc: arnd@arndb.de Cc: daniel.lezcano@linaro.org Cc: mark.rutland@arm.com Cc: pawel.moll@arm.com Cc: robh+dt@kernel.org Cc: ijc+devicetree@hellion.org.uk Cc: galak@codeaurora.org Cc: mcoquelin.stm32@gmail.com Cc: linux-arm-kernel@lists.infradead.org Cc: shawn.guo@linaro.org Cc: kernel@pengutronix.de Cc: jason@lakedaemon.net Link: http://lkml.kernel.org/r/1431769465-26867-2-git-send-email-stefan@agner.ch Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-18genirq: Don't suspend nested_thread irqs over system suspendNeilBrown
Nested IRQs can only fire when the parent irq fires. So when the parent is suspended, there is no need to suspend the child irq. Suspending nested irqs can cause a problem is they are suspended or resumed in the wrong order. If an interrupt fires while the parent is active but the child is suspended, then the interrupt will not be acknowledged properly and so an interrupt storm can result. This is particularly likely if the parent is resumed before the child, and the interrupt was raised during suspend. Ensuring correct ordering would be possible, but it is simpler to just never suspend nested interrupts. Signed-off-by: NeilBrown <neil@brown.name> Cc: GTA04 owners <gta04-owner@goldelico.com> Cc: Kalle Jokiniemi <kalle.jokiniemi@jollamobile.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Link: http://lkml.kernel.org/r/20150517151934.2393e8f8@notabene.brown Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-18sched,perf: Fix periodic timersPeter Zijlstra
In the below two commits (see Fixes) we have periodic timers that can stop themselves when they're no longer required, but need to be (re)-started when their idle condition changes. Further complications is that we want the timer handler to always do the forward such that it will always correctly deal with the overruns, and we do not want to race such that the handler has already decided to stop, but the (external) restart sees the timer still active and we end up with a 'lost' timer. The problem with the current code is that the re-start can come before the callback does the forward, at which point the forward from the callback will WARN about forwarding an enqueued timer. Now, conceptually its easy to detect if you're before or after the fwd by comparing the expiration time against the current time. Of course, that's expensive (and racy) because we don't have the current time. Alternatively one could cache this state inside the timer, but then everybody pays the overhead of maintaining this extra state, and that is undesired. The only other option that I could see is the external timer_active variable, which I tried to kill before. I would love a nicer interface for this seemingly simple 'problem' but alas. Fixes: 272325c4821f ("perf: Fix mux_interval hrtimer wreckage") Fixes: 77a4d1a1b9a1 ("sched: Cleanup bandwidth timers") Cc: pjt@google.com Cc: tglx@linutronix.de Cc: klamm@yandex-team.ru Cc: mingo@kernel.org Cc: bsegall@google.com Cc: hpa@zytor.com Cc: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20150514102311.GX21418@twins.programming.kicks-ass.net
2015-05-18livepatch: Prevent patch inconsistencies if the coming module notifier failsMinfei Huang
The previous patches can be applied, once the corresponding module is loaded. In general, the patch will do relocation (if necessary) and obtain/verify function address before we start to enable patch. There are three different situations in which the coming module notifier can fail: 1) relocations are not applied for some reason. In this case kallsyms for module symbol is not called at all. The patch is not applied to the module. If the user disable and enable patch again, there is possible bug in klp_enable_func. If the user specified func->old_addr for some function in the module (and he shouldn't do that, but nevertheless) our warning would not catch it, ftrace will reject to register the handler because of wrong address or will register the handler for wrong address. 2) relocations are applied successfully, but kallsyms lookup fails. In this case func->old_addr can be correct for all previous lookups, 0 for current failed one, and "unspecified" for the rest. If we undergo the same scenario as in 1, the behaviour differs for three cases, but the patch is not enabled anyway. 3) the object is initialized, but klp_enable_object fails in the notifier due to possible ftrace error. Since it is improbable that ftrace would heal itself in the future, we would get those errors everytime the patch is enabled. In order to fix above situations, we can make obj->mod to NULL, if the coming modified notifier fails. Signed-off-by: Minfei Huang <mnfhuang@gmail.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-05-17sched: Fix function declaration return type mismatchNicholas Mc Guire
static code checking was unhappy with: ./kernel/sched/fair.c:162 WARNING: return of wrong type int != unsigned int get_update_sysctl_factor() is declared to return int but is currently returning an unsigned int. The first few preprocessed lines are: static int get_update_sysctl_factor(void) { unsigned int cpus = ({ int __min1 = (cpumask_weight(cpu_online_mask)); int __min2 = (8); __min1 < __min2 ? __min1: __min2; }); unsigned int factor; The type used by min_t() should be 'unsigned int' and the return type of get_update_sysctl_factor() should also be 'unsigned int' as its call-site update_sysctl() is expecting 'unsigned int' and the values utilizing: 'factor' 'sysctl_sched_min_granularity' 'sched_nr_latency' 'sysctl_sched_wakeup_granularity' ... are also all 'unsigned int', plus cpumask_weight() is also returning 'unsigned int'. So the natural type to use around here is 'unsigned int'. ( Patch was compile tested with x86_64_defconfig + CONFIG_SCHED_DEBUG=y and the changed sections in kernel/sched/fair.i were reviewed. ) Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> [ Improved the changelog a bit. ] Cc: H. Peter Anvin <hpa@zytor.com> 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/1431716742-11077-1-git-send-email-hofrat@osadl.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-15Merge 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: "Two fixes: a suspend/resume related regression fix, and an RT priority boosting fix" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Fix regression in cpuset_cpu_inactive() for suspend sched: Handle priority boosted tasks proper in setscheduler()
2015-05-15Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Mostly tooling fixes, but also a lockdep annotation fix, a PMU event list fix and a new model addition" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tools/liblockdep: Fix compilation error tools/liblockdep: Fix linker error in case of cross compile perf tools: Use getconf to determine number of online CPUs tools: Fix tools/vm build perf/x86/rapl: Enable Broadwell-U RAPL support perf/x86/intel: Fix SLM cache event list perf: Annotate inherited event ctx->mutex recursion
2015-05-15PM / tick: Add tracepoints for suspend-to-idle diagnosticsRafael J. Wysocki
Add suspend/resume tracepoints to tick_freeze() and tick_unfreeze() to catch when timekeeping is suspended and resumed during suspend-to-idle so as to be able to check whether or not we enter the "frozen" state and to measure the time spent in it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-14sched / idle: Call default_idle_call() from cpuidle_enter_state()Rafael J. Wysocki
The check of the cpuidle_enter() return value against -EBUSY made in call_cpuidle() will not be necessary any more if cpuidle_enter_state() calls default_idle_call() directly when it is about to return -EBUSY, so make that happen and eliminate the check. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Kevin Hilman <khilman@linaro.org>
2015-05-14sched / idle: Call idle_set_state() from cpuidle_enter_state()Rafael J. Wysocki
Introduce a wrapper function around idle_set_state() called sched_idle_set_state() that will pass this_rq() to it as the first argument and make cpuidle_enter_state() call the new function before and after entering the target state. At the same time, remove direct invocations of idle_set_state() from call_cpuidle(). This will allow the invocation of default_idle_call() to be moved from call_cpuidle() to cpuidle_enter_state() safely and call_cpuidle() to be simplified a bit as a result. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Kevin Hilman <khilman@linaro.org>
2015-05-13tracing: Rename ftrace_raw_##call event structures to trace_event_raw_##callSteven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The ftrace_raw_##call structures are built by macros for trace events. They have nothing to do with function tracing. Rename them. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13rtmutex: Warn if trylock is called from hard/softirq contextThomas Gleixner
rt_mutex_trylock() must be called from thread context. It can be called from atomic regions (preemption or interrupts disabled), but not from hard/softirq/nmi context. Add a warning to alert abusers. The reasons for this are: 1) There is a potential deadlock in the slowpath 2) Another cpu which blocks on the rtmutex will boost the task which allegedly locked the rtmutex, but that cannot work because the hard/softirq context borrows the task context. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de>
2015-05-13tracing: Rename ftrace_trigger_soft_disabled() to trace_trigger_soft_disabled()Steven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The ftrace_trigger_soft_disabled() tests if a trace_event is soft disabled (called but not traced), and returns true if it is. It has nothing to do with function tracing and should be renamed. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename FTRACE_EVENT_FL_* flags to EVENT_FILE_FL_*Steven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The FTRACE_EVENT_FL_* flags are flags to do with the trace_event files in the tracefs directory. They are not related to function tracing. Rename them to a more descriptive name. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename struct ftrace_subsystem_dir to trace_subsystem_dirSteven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The structure ftrace_subsystem_dir holds the information about trace event subsystems. It should not be named ftrace, rename it to trace_subsystem_dir. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Four minor merge conflicts: 1) qca_spi.c renamed the local variable used for the SPI device from spi_device to spi, meanwhile the spi_set_drvdata() call got moved further up in the probe function. 2) Two changes were both adding new members to codel params structure, and thus we had overlapping changes to the initializer function. 3) 'net' was making a fix to sk_release_kernel() which is completely removed in 'net-next'. 4) In net_namespace.c, the rtnl_net_fill() call for GET operations had the command value fixed, meanwhile 'net-next' adjusted the argument signature a bit. This also matches example merge resolutions posted by Stephen Rothwell over the past two days. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-13tracing: Rename ftrace_event_name() to trace_event_name()Steven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. ftrace_event_name() returns the name of an event tracepoint, has nothing to do with function tracing. Rename it to trace_event_name(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename FTRACE_MAX_EVENT to TRACE_EVENT_TYPE_MAXSteven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. Rename the max trace_event type size to something more descriptive and appropriate. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_output functions to trace_outputSteven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The ftrace_output_*() and ftrace_raw_output_*() functions represent the trace_event code. Rename them to just trace_output or trace_raw_output. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_event_buffer to trace_event_buffer.Steven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The ftrace_event_buffer functions and data structures are for trace_events and not for function hooks. Rename them to trace_event_buffer*. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_event_{call,class} to trace_event_{call,class}Steven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The structures ftrace_event_call and ftrace_event_class have nothing to do with the function hooks, and are really trace_event structures. Rename ftrace_event_* to trace_event_*. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_event_file to trace_event_fileSteven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The structure ftrace_event_file is really about trace events and not "ftrace". Rename it to trace_event_file. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename (un)register_ftrace_event() to (un)register_trace_event()Steven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The functions (un)register_ftrace_event() is really about trace_events, and the name should be register_trace_event() instead. Also renamed ftrace_event_reg() to trace_event_reg() for the same reason. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_print_*() functions ta trace_print_*()Steven Rostedt (Red Hat)
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The functions ftrace_print_*() are not part of the function infrastructure, and the names can be confusing. Rename them to be trace_print_*(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_event.h to trace_events.hSteven Rostedt (Red Hat)
The term "ftrace" is really the infrastructure of the function hooks, and not the trace events. Rename ftrace_event.h to trace_events.h to represent the trace_event infrastructure and decouple the term ftrace from it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13workqueue: fix a typoChen Hanxiao
s/detemined/determined Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2015-05-13PM / sleep: Fix symbol name in a comment in kernel/power/main.cRafael J. Wysocki
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-13locking/rtmutex: Drop usage of __HAVE_ARCH_CMPXCHGSebastian Andrzej Siewior
The rtmutex code is the only user of __HAVE_ARCH_CMPXCHG and we have a few other user of cmpxchg() which do not care about __HAVE_ARCH_CMPXCHG. This define was first introduced in 23f78d4a0 ("[PATCH] pi-futex: rt mutex core") which is v2.6.18. The generic cmpxchg was introduced later in 068fbad288 ("Add cmpxchg_local to asm-generic for per cpu atomic operations") which is v2.6.25. Back then something was required to get rtmutex working with the fast path on architectures without cmpxchg and this seems to be the result. It popped up recently on rt-users because ARM (v6+) does not define __HAVE_ARCH_CMPXCHG (even that it implements it) which results in slower locking performance in the fast path. To put some numbers on it: preempt -RT, am335x, 10 loops of 100000 invocations of rt_spin_lock() + rt_spin_unlock() (time "total" is the average of the 10 loops for the 100000 invocations, "loop" is "total / 100000 * 1000"): cmpxchg | slowpath used || cmpxchg used | total | loop || total | loop --------|-----------|-------||------------|------- ARMv6 | 9129.4 us | 91 ns || 3311.9 us | 33 ns generic | 9360.2 us | 94 ns || 10834.6 us | 108 ns ----------------------------||-------------------- Forcing it to generic cmpxchg() made things worse for the slowpath and even worse in cmpxchg() path. It boils down to 14ns more per lock+unlock in a cache hot loop so it might not be that much in real world. The last test was a substitute for pre ARMv6 machine but then I was able to perform the comparison on imx28 which is ARMv5 and therefore is always is using the generic cmpxchg implementation. And the numbers: | total | loop -------- |----------- |-------- slowpath | 263937.2 us | 2639 ns cmpxchg | 16934.2 us | 169 ns -------------------------------- The numbers are larger since the machine is slower in general. However, letting rtmutex use cmpxchg() instead the slowpath seem to improve things. Since from the ARM (tested on am335x + imx28) point of view always using cmpxchg() in rt_mutex_lock() + rt_mutex_unlock() makes sense I would drop the define. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: will.deacon@arm.com Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20150225175613.GE6823@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>