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2015-09-02Merge branch 'timers-core-for-linus' of ↵Linus Torvalds7-75/+82
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "Rather large, but nothing exiting: - new range check for settimeofday() to prevent that boot time becomes negative. - fix for file time rounding - a few simplifications of the hrtimer code - fix for the proc/timerlist code so the output of clock realtime timers is accurate - more y2038 work - tree wide conversion of clockevent drivers to the new callbacks" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (88 commits) hrtimer: Handle failure of tick_init_highres() gracefully hrtimer: Unconfuse switch_hrtimer_base() a bit hrtimer: Simplify get_target_base() by returning current base hrtimer: Drop return code of hrtimer_switch_to_hres() time: Introduce timespec64_to_jiffies()/jiffies_to_timespec64() time: Introduce current_kernel_time64() time: Introduce struct itimerspec64 time: Add the common weak version of update_persistent_clock() time: Always make sure wall_to_monotonic isn't positive time: Fix nanosecond file time rounding in timespec_trunc() timer_list: Add the base offset so remaining nsecs are accurate for non monotonic timers cris/time: Migrate to new 'set-state' interface kernel: broadcast-hrtimer: Migrate to new 'set-state' interface xtensa/time: Migrate to new 'set-state' interface unicore/time: Migrate to new 'set-state' interface um/time: Migrate to new 'set-state' interface sparc/time: Migrate to new 'set-state' interface sh/localtimer: Migrate to new 'set-state' interface score/time: Migrate to new 'set-state' interface s390/time: Migrate to new 'set-state' interface ...
2015-09-01Merge branch 'timers-nohz-for-linus' of ↵Linus Torvalds2-48/+34
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull NOHZ updates from Ingo Molnar: "The main changes, mostly written by Frederic Weisbecker, include: - Fix some jiffies based cputime assumptions. (No real harm because the concerned code isn't used by full dynticks.) - Simplify jiffies <-> usecs conversions. Remove dead code. - Remove early hacks on nohz full code that avoided messing up idle nohz internals. Now nohz integrates well full and idle and such hack have become needless. - Restart nohz full tick from irq exit. (A simplification and a preparation for future optimization on scheduler kick to nohz full) - Code cleanups. - Tile driver isolation enhancement on top of nohz. (Chris Metcalf)" * 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: nohz: Remove useless argument on tick_nohz_task_switch() nohz: Move tick_nohz_restart_sched_tick() above its users nohz: Restart nohz full tick from irq exit nohz: Remove idle task special case nohz: Prevent tilegx network driver interrupts alpha: Fix jiffies based cputime assumption apm32: Fix cputime == jiffies assumption jiffies: Remove HZ > USEC_PER_SEC special case
2015-09-01Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The main RCU changes in this cycle are: - the combination of tree geometry-initialization simplifications and OS-jitter-reduction changes to expedited grace periods. These two are stacked due to the large number of conflicts that would otherwise result. - privatize smp_mb__after_unlock_lock(). This commit moves the definition of smp_mb__after_unlock_lock() to kernel/rcu/tree.h, in recognition of the fact that RCU is the only thing using this, that nothing else is likely to use it, and that it is likely to go away completely. - documentation updates. - torture-test updates. - misc fixes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits) rcu,locking: Privatize smp_mb__after_unlock_lock() rcu: Silence lockdep false positive for expedited grace periods rcu: Don't disable CPU hotplug during OOM notifiers scripts: Make checkpatch.pl warn on expedited RCU grace periods rcu: Update MAINTAINERS entry rcu: Clarify CONFIG_RCU_EQS_DEBUG help text rcu: Fix backwards RCU_LOCKDEP_WARN() in synchronize_rcu_tasks() rcu: Rename rcu_lockdep_assert() to RCU_LOCKDEP_WARN() rcu: Make rcu_is_watching() really notrace cpu: Wait for RCU grace periods concurrently rcu: Create a synchronize_rcu_mult() rcu: Fix obsolete priority-boosting comment rcu: Use WRITE_ONCE in RCU_INIT_POINTER rcu: Hide RCU_NOCB_CPU behind RCU_EXPERT rcu: Add RCU-sched flavors of get-state and cond-sync rcu: Add fastpath bypassing funnel locking rcu: Rename RCU_GP_DONE_FQS to RCU_GP_DOING_FQS rcu: Pull out wait_event*() condition into helper function documentation: Describe new expedited stall warnings rcu: Add stall warnings to synchronize_sched_expedited() ...
2015-08-22hrtimer: Handle failure of tick_init_highres() gracefullyGuenter Roeck1-0/+1
Commit 75e3b37d0598 ("hrtimer: Drop return code of hrtimer_switch_to_hres()") drops the return code of hrtimer_switch_to_hres(). While doing so, it also drops the return statement itself on failure. This may cause a system hang. Seen when running arm:multi_v7_defconfig in qemu with devicetree file vexpress-v2p-ca9. Fixes: 75e3b37d0598 ("hrtimer: Drop return code of hrtimer_switch_to_hres()") Cc: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Link: http://lkml.kernel.org/r/1440231047-16256-1-git-send-email-linux@roeck-us.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-08-20Merge branch 'fortglx/4.3/time' of ↵Thomas Gleixner4-29/+40
https://git.linaro.org/people/john.stultz/linux into timers/core - A handful or y2038 related items - A walltime to monotonic limit - Small fixes for timespec_trunc() and timer_list output
2015-08-18hrtimer: Unconfuse switch_hrtimer_base() a bitFrederic Weisbecker1-8/+17
The variable called "this_base" is confusing because its name suggests it's of "struct hrtimer_clock_base" type, along with "base" and "new_base" which doesn't help understanding this complicated function. Make its name clearer and fix the misleading comment while at it. [ tglx: Fixed the comment for real ] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/1439907509-9553-3-git-send-email-fweisbec@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-08-18hrtimer: Simplify get_target_base() by returning current baseFrederic Weisbecker1-2/+2
Instead of fetching again the current cpu base, just take it from the parameter. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/1439907509-9553-2-git-send-email-fweisbec@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-08-18timer: Write timer->flags atomicallyEric Dumazet1-2/+2
lock_timer_base() cannot prevent the following : CPU1 ( in __mod_timer() timer->flags |= TIMER_MIGRATING; spin_unlock(&base->lock); base = new_base; spin_lock(&base->lock); // The next line clears TIMER_MIGRATING timer->flags &= ~TIMER_BASEMASK; CPU2 (in lock_timer_base()) see timer base is cpu0 base spin_lock_irqsave(&base->lock, *flags); if (timer->flags == tf) return base; // oops, wrong base timer->flags |= base->cpu // too late We must write timer->flags in one go, otherwise we can fool other cpus. Fixes: bc7a34b8b9eb ("timer: Reduce timer migration overhead if disabled") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jon Christopherson <jon@jons.org> Cc: David Miller <davem@davemloft.net> Cc: xen-devel@lists.xen.org Cc: david.vrabel@citrix.com Cc: Sander Eikelenboom <linux@eikelenboom.it> Link: http://lkml.kernel.org/r/1439831928.32680.11.camel@edumazet-glaptop2.roam.corp.google.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de>
2015-08-18hrtimer: Drop return code of hrtimer_switch_to_hres()Luiz Capitulino1-4/+2
It's not checked by the caller. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Link: http://lkml.kernel.org/r/20150811164043.538241ef@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-08-17time: Introduce timespec64_to_jiffies()/jiffies_to_timespec64()Baolin Wang1-8/+13
The conversion between struct timespec and jiffies is not year 2038 safe on 32bit systems. Introduce timespec64_to_jiffies() and jiffies_to_timespec64() functions which use struct timespec64 to make it ready for 2038 issue. Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-08-17time: Introduce current_kernel_time64()Baolin Wang1-3/+3
The current_kernel_time() is not year 2038 safe on 32bit systems since it returns a timespec value. Introduce current_kernel_time64() which returns a timespec64 value. Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-08-17time: Add the common weak version of update_persistent_clock()Xunlei Pang1-0/+5
The weak update_persistent_clock64() calls update_persistent_clock(), if the architecture defines an update_persistent_clock64() to replace and remove its update_persistent_clock() version, when building the kernel the linker will throw an undefined symbol error, that is, any arch that switches to update_persistent_clock64() will have this issue. To solve the issue, we add the common weak update_persistent_clock(). Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-08-17time: Always make sure wall_to_monotonic isn't positiveWang YanQing1-3/+10
Two issues were found on an IMX6 development board without an enabled RTC device(resulting in the boot time and monotonic time being initialized to 0). Issue 1:exportfs -a generate: "exportfs: /opt/nfs/arm does not support NFS export" Issue 2:cat /proc/stat: "btime 4294967236" The same issues can be reproduced on x86 after running the following code: int main(void) { struct timeval val; int ret; val.tv_sec = 0; val.tv_usec = 0; ret = settimeofday(&val, NULL); return 0; } Two issues are different symptoms of same problem: The reason is a positive wall_to_monotonic pushes boot time back to the time before Epoch, and getboottime will return negative value. In symptom 1: negative boot time cause get_expiry() to overflow time_t when input expire time is 2147483647, then cache_flush() always clears entries just added in ip_map_parse. In symptom 2: show_stat() uses "unsigned long" to print negative btime value returned by getboottime. This patch fix the problem by prohibiting time from being set to a value which would cause a negative boot time. As a result one can't set the CLOCK_REALTIME time prior to (1970 + system uptime). Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Wang YanQing <udknight@gmail.com> [jstultz: reworded commit message] Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-08-17time: Fix nanosecond file time rounding in timespec_trunc()Karsten Blees1-14/+8
timespec_trunc() avoids rounding if granularity <= nanoseconds-per-jiffie (or TICK_NSEC). This optimization assumes that: 1. current_kernel_time().tv_nsec is already rounded to TICK_NSEC (i.e. with HZ=1000 you'd get 1000000, 2000000, 3000000... but never 1000001). This is no longer true (probably since hrtimers introduced in 2.6.16). 2. TICK_NSEC is evenly divisible by all possible granularities. This may be true for HZ=100, 250, 1000, but obviously not for HZ=300 / TICK_NSEC=3333333 (introduced in 2.6.20). Thus, sub-second portions of in-core file times are not rounded to on-disk granularity. I.e. file times may change when the inode is re-read from disk or when the file system is remounted. This affects all file systems with file time granularities > 1 ns and < 1s, e.g. CEPH (1000 ns), UDF (1000 ns), CIFS (100 ns), NTFS (100 ns) and FUSE (configurable from user mode via struct fuse_init_out.time_gran). Steps to reproduce with e.g. UDF: $ dd if=/dev/zero of=udfdisk count=10000 && mkudffs udfdisk $ mkdir udf && mount udfdisk udf $ touch udf/test && stat -c %y udf/test 2015-06-09 10:22:56.130006767 +0200 $ umount udf && mount udfdisk udf $ stat -c %y udf/test 2015-06-09 10:22:56.130006000 +0200 Remounting truncates the mtime to 1 µs. Fix the rounding in timespec_trunc() and update the documentation. timespec_trunc() is exclusively used to calculate inode's [acm]time (mostly via current_fs_time()), and always with super_block.s_time_gran as second argument. So this can safely be changed without side effects. Note: This does _not_ fix the issue for FAT's 2 second mtime resolution, as super_block.s_time_gran isn't prepared to handle different ctime / mtime / atime resolutions nor resolutions > 1 second. Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Karsten Blees <blees@dcon.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-08-17timer_list: Add the base offset so remaining nsecs are accurate for non ↵John Stultz1-1/+1
monotonic timers I noticed for non-monotonic timers in timer_list, some of the output looked a little confusing. For example: #1: <0000000000000000>, posix_timer_fn, S:01, hrtimer_start_range_ns, leap-a-day/2360 # expires at 1434412800000000000-1434412800000000000 nsecs [in 1434410725062375469 to 1434410725062375469 nsecs] You'll note the relative time till the expiration "[in xxx to yyy nsecs]" is incorrect. This is because its printing the delta between CLOCK_MONOTONIC time to the CLOCK_REALTIME expiration. This patch fixes this issue by adding the clock offset to the "now" time which we use to calculate the delta. Cc: Prarit Bhargava <prarit@redhat.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Jan Kara <jack@suse.cz> Cc: Jiri Bohac <jbohac@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-08-12Merge branch 'for-mingo' of ↵Ingo Molnar1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU changes from Paul E. McKenney: - The combination of tree geometry-initialization simplifications and OS-jitter-reduction changes to expedited grace periods. These two are stacked due to the large number of conflicts that would otherwise result. [ With one addition, a temporary commit to silence a lockdep false positive. Additional changes to the expedited grace-period primitives (queued for 4.4) remove the cause of this false positive, and therefore include a revert of this temporary commit. ] - Documentation updates. - Torture-test updates. - Miscellaneous fixes. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-10kernel: broadcast-hrtimer: Migrate to new 'set-state' interfaceViresh Kumar1-29/+20
Migrate broadcast-hrtimer driver to the new 'set-state' interface provided by clockevents core, the earlier 'set-mode' interface is marked obsolete now. Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-08-01clockevents: Drop redundant cpumask check in tick_check_new_device()Luiz Capitulino1-3/+0
The same check is performed by tick_check_percpu(). Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Link: http://lkml.kernel.org/r/20150729151417.069d1bb0@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-29nohz: Remove useless argument on tick_nohz_task_switch()Frederic Weisbecker1-1/+1
Leftover from early code. Cc: Christoph Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2015-07-29nohz: Move tick_nohz_restart_sched_tick() above its usersFrederic Weisbecker1-18/+16
Fix the function declaration/definition dance. Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2015-07-29nohz: Restart nohz full tick from irq exitFrederic Weisbecker1-24/+10
Restart the tick when necessary from the irq exit path. It makes nohz full more flexible, simplify the related IPIs and doesn't bring significant overhead on irq exit. In a longer term view, it will allow us to piggyback the nohz kick on the scheduler IPI in the future instead of sending a dedicated IPI that often doubles the scheduler IPI on task wakeup. This will require more changes though including careful review of resched_curr() callers to include nohz full needs. Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2015-07-29nohz: Remove idle task special caseFrederic Weisbecker1-5/+3
On nohz full early days, idle dynticks and full dynticks weren't well integrated and we couldn't risk full dynticks calls on idle without risking messing up tick idle statistics. This is why we prevented such thing to happen. Nowadays full dynticks and idle dynticks are better integrated and interact without known issue. So lets remove that. Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2015-07-29jiffies: Remove HZ > USEC_PER_SEC special caseFrederic Weisbecker1-3/+7
HZ never goes much further 1000 and a bit. And if we ever reach one tick per microsecond, we might be having a problem. Lets stop maintaining this special case, just leave a paranoid check. Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@kernel.org> Cc; John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2015-07-14tick: Move the export of tick_broadcast_oneshot_control to the proper placeThomas Gleixner2-1/+1
tick_broadcast_oneshot_control got moved from tick-broadcast to tick-common, but the export stayed in the old place. Fix it up. Fixes: f32dd1170511 'tick/broadcast: Make idle check independent from mode and config' Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-11tick/broadcast: Prevent NULL pointer dereferenceThomas Gleixner1-8/+10
Dan reported that the recent changes to the broadcast code introduced a potential NULL dereference. Add the proper check. Fixes: e0454311903d "tick/broadcast: Sanity check the shutdown of the local clock_event" Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-07tick/broadcast: Handle spurious interrupts gracefullyThomas Gleixner1-0/+7
Andriy reported that on a virtual machine the warning about negative expiry time in the clock events programming code triggered: hpet: hpet0 irq 40 for MSI hpet: hpet1 irq 41 for MSI Switching to clocksource hpet WARNING: at kernel/time/clockevents.c:239 [<ffffffff810ce6eb>] clockevents_program_event+0xdb/0xf0 [<ffffffff810cf211>] tick_handle_periodic_broadcast+0x41/0x50 [<ffffffff81016525>] timer_interrupt+0x15/0x20 When the second hpet is installed as a per cpu timer the broadcast event is not longer required and stopped, which sets the next_evt of the broadcast device to KTIME_MAX. If after that a spurious interrupt happens on the broadcast device, then the current code blindly handles it and tries to reprogram the broadcast device afterwards, which adds the period to next_evt. KTIME_MAX + period results in a negative expiry value causing the WARN_ON in the clockevents code to trigger. Add a proper check for the state of the broadcast device into the interrupt handler and return if the interrupt is spurious. [ Folded in pointer fix from Sudeep ] Reported-by: Andriy Gapon <avg@FreeBSD.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20150705205221.802094647@linutronix.de
2015-07-07tick/broadcast: Check for hrtimer broadcast active earlyThomas Gleixner1-10/+26
If the current cpu is the one which has the hrtimer based broadcast queued then we better return busy immediately instead of going through loops and hoops to figure that out. [ Split out from a larger combo patch ] Tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Suzuki Poulose <Suzuki.Poulose@arm.com> Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Cc: Catalin Marinas <Catalin.Marinas@arm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07tick/broadcast: Return busy when IPI is pendingThomas Gleixner1-3/+7
Tell the idle code not to go deep if the broadcast IPI is about to arrive. [ Split out from a larger combo patch ] Tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Suzuki Poulose <Suzuki.Poulose@arm.com> Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Cc: Catalin Marinas <Catalin.Marinas@arm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07tick/broadcast: Return busy if periodic mode and hrtimer broadcastThomas Gleixner1-1/+5
If the system is in periodic mode and the broadcast device is hrtimer based, return busy as we have no proper handling for this. [ Split out from a larger combo patch ] Tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Suzuki Poulose <Suzuki.Poulose@arm.com> Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Cc: Catalin Marinas <Catalin.Marinas@arm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07tick/broadcast: Move the check for periodic mode inside state handlingThomas Gleixner1-14/+8
We need to check more than the periodic mode for proper operation in all runtime combinations. To avoid code duplication move the check into the enter state handling. No functional change. [ Split out from a larger combo patch ] Reported-and-tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Suzuki Poulose <Suzuki.Poulose@arm.com> Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Cc: Catalin Marinas <Catalin.Marinas@arm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07tick/broadcast: Prevent deep idle if no broadcast device availableThomas Gleixner1-0/+7
Add a check for a installed broadcast device to the oneshot control function and return busy if not. [ Split out from a larger combo patch ] Reported-and-tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Suzuki Poulose <Suzuki.Poulose@arm.com> Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Cc: Catalin Marinas <Catalin.Marinas@arm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07tick/broadcast: Make idle check independent from mode and configThomas Gleixner3-15/+42
Currently the broadcast busy check, which prevents the idle code from going into deep idle, works only in one shot mode. If NOHZ and HIGHRES are off (config or command line) there is no sanity check at all, so under certain conditions cpus are allowed to go into deep idle, where the local timer stops, and are not woken up again because there is no broadcast timer installed or a hrtimer based broadcast device is not evaluated. Move tick_broadcast_oneshot_control() into the common code and provide proper subfunctions for the various config combinations. The common check in tick_broadcast_oneshot_control() is for the C3STOP misfeature flag of the local clock event device. If its not set, idle can proceed. If set, further checks are necessary. Provide checks for the trivial cases: - If broadcast is disabled in the config, then return busy - If oneshot mode (NOHZ/HIGHES) is disabled in the config, return busy if the broadcast device is hrtimer based. - If oneshot mode is enabled in the config call the original tick_broadcast_oneshot_control() function. That function needs extra checks which will be implemented in seperate patches. [ Split out from a larger combo patch ] Reported-and-tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Suzuki Poulose <Suzuki.Poulose@arm.com> Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Cc: Catalin Marinas <Catalin.Marinas@arm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07tick/broadcast: Sanity check the shutdown of the local clock_eventThomas Gleixner1-7/+16
The broadcast code shuts down the local clock event unconditionally even if no broadcast device is installed or if the broadcast device is hrtimer based. Add proper sanity checks. [ Split out from a larger combo patch ] Reported-and-tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Suzuki Poulose <Suzuki.Poulose@arm.com> Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Cc: Catalin Marinas <Catalin.Marinas@arm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07tick/broadcast: Prevent hrtimer recursionThomas Gleixner1-1/+15
The hrtimer based broadcast vehicle can cause a hrtimer recursion which went unnoticed until we changed the hrtimer expiry code to keep track of the currently running timer. local_timer_interrupt() local_handler() hrtimer_interrupt() expire_hrtimers() broadcast_hrtimer() send_ipis() local_handler() hrtimer_interrupt() .... Solution is simple: Prevent the local handler call from the broadcast code when the broadcast 'device' is hrtimer based. [ Split out from a larger combo patch ] Tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Suzuki Poulose <Suzuki.Poulose@arm.com> Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Cc: Catalin Marinas <Catalin.Marinas@arm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
2015-07-07clockevents: Allow set-state callbacks to be optionalViresh Kumar1-15/+9
Its mandatory for the drivers to provide set_state_{oneshot|periodic}() (only if related modes are supported) and set_state_shutdown() callbacks today, if they are implementing the new set-state interface. But this leads to unnecessary noop callbacks for drivers which don't want to implement them. Over that, it will lead to a full function call for nothing really useful. Lets make all set-state callbacks optional. Suggested-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: http://lkml.kernel.org/r/1436256875-15562-1-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-06rcu: Drop RCU_USER_QS in favor of NO_HZ_FULLPaul E. McKenney1-2/+0
The RCU_USER_QS Kconfig parameter is now just a synonym for NO_HZ_FULL, so this commit eliminates RCU_USER_QS, replacing all uses with NO_HZ_FULL. Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
2015-07-02Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds2-3/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Thomas Gleixner: "This contains: - a build regression fix introduced by the timeconst move - a hotplug regression fix introduced by the timer wheel diet - a cpu hotplug bug fix for the exynos clocksource driver" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: time: Remove development rules from Kbuild/Makefile timer: Fix hotplug regression clocksource: exynos_mct: Avoid blocking calls in the cpu hotplug notifier
2015-07-01Merge tag 'modules-next-for-linus' of ↵Linus Torvalds1-27/+2
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "Main excitement here is Peter Zijlstra's lockless rbtree optimization to speed module address lookup. He found some abusers of the module lock doing that too. A little bit of parameter work here too; including Dan Streetman's breaking up the big param mutex so writing a parameter can load another module (yeah, really). Unfortunately that broke the usual suspects, !CONFIG_MODULES and !CONFIG_SYSFS, so those fixes were appended too" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (26 commits) modules: only use mod->param_lock if CONFIG_MODULES param: fix module param locks when !CONFIG_SYSFS. rcu: merge fix for Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE() module: add per-module param_lock module: make perm const params: suppress unused variable error, warn once just in case code changes. modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'. kernel/module.c: avoid ifdefs for sig_enforce declaration kernel/workqueue.c: remove ifdefs over wq_power_efficient kernel/params.c: export param_ops_bool_enable_only kernel/params.c: generalize bool_enable_only kernel/module.c: use generic module param operaters for sig_enforce kernel/params: constify struct kernel_param_ops uses sysfs: tightened sysfs permission checks module: Rework module_addr_{min,max} module: Use __module_address() for module_address_lookup() module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING module: Optimize __module_address() using a latched RB-tree rbtree: Implement generic latch_tree seqlock: Introduce raw_read_seqcount_latch() ...
2015-07-01time: Remove development rules from Kbuild/MakefileThomas Gleixner1-2/+0
time.o gets rebuilt unconditionally due to a leftover Makefile rule which was placed there for development purposes. Remove it along with the commented out always rule in the toplevel Kbuild file. Fixes: 0a227985d4a9 'time: Move timeconst.h into include/generated' Reported-by; Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Nicholas Mc Guire <der.herr@hofr.at>
2015-06-26timer: Fix hotplug regressionThomas Gleixner1-1/+2
The recent timer wheel rework removed the get/put_cpu_var() pair in the hotplug migration code, which results in: BUG: using smp_processor_id() in preemptible [00000000] code: hib.sh/2845 ... [<ffffffff810d4fa3>] timer_cpu_notify+0x53/0x12 That hunk is a leftover from an earlier iteration and went unnoticed so far. Restore the previous code which was obviously correct. Fixes: 0eeda71bc30d 'timer: Replace timer base by a cpu index' Reported-and_tested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-06-24Merge tag 'pm+acpi-4.2-rc1' of ↵Linus Torvalds1-4/+13
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management and ACPI updates from Rafael Wysocki: "The rework of backlight interface selection API from Hans de Goede stands out from the number of commits and the number of affected places perspective. The cpufreq core fixes from Viresh Kumar are quite significant too as far as the number of commits goes and because they should reduce CPU online/offline overhead quite a bit in the majority of cases. From the new featues point of view, the ACPICA update (to upstream revision 20150515) adding support for new ACPI 6 material to ACPICA is the one that matters the most as some new significant features will be based on it going forward. Also included is an update of the ACPI device power management core to follow ACPI 6 (which in turn reflects the Windows' device PM implementation), a PM core extension to support wakeup interrupts in a more generic way and support for the ACPI _CCA device configuration object. The rest is mostly fixes and cleanups all over and some documentation updates, including new DT bindings for Operating Performance Points. There is one fix for a regression introduced in the 4.1 cycle, but it adds quite a number of lines of code, it wasn't really ready before Thursday and you were on vacation, so I refrained from pushing it on the last minute for 4.1. Specifics: - ACPICA update to upstream revision 20150515 including basic support for ACPI 6 features: new ACPI tables introduced by ACPI 6 (STAO, XENV, WPBT, NFIT, IORT), changes related to the other tables (DTRM, FADT, LPIT, MADT), new predefined names (_BTH, _CR3, _DSD, _LPI, _MTL, _PRR, _RDI, _RST, _TFP, _TSN), fixes and cleanups (Bob Moore, Lv Zheng). - ACPI device power management core code update to follow ACPI 6 which reflects the ACPI device power management implementation in Windows (Rafael J Wysocki). - rework of the backlight interface selection logic to reduce the number of kernel command line options and improve the handling of DMI quirks that may be involved in that and to make the code generally more straightforward (Hans de Goede). - fixes for the ACPI Embedded Controller (EC) driver related to the handling of EC transactions (Lv Zheng). - fix for a regression related to the ACPI resources management and resulting from a recent change of ACPI initialization code ordering (Rafael J Wysocki). - fix for a system initialization regression related to ACPI introduced during the 3.14 cycle and caused by running the code that switches the platform over to the ACPI mode too early in the initialization sequence (Rafael J Wysocki). - support for the ACPI _CCA device configuration object related to DMA cache coherence (Suravee Suthikulpanit). - ACPI/APEI fixes and cleanups (Jiri Kosina, Borislav Petkov). - ACPI battery driver cleanups (Luis Henriques, Mathias Krause). - ACPI processor driver cleanups (Hanjun Guo). - cleanups and documentation update related to the ACPI device properties interface based on _DSD (Rafael J Wysocki). - ACPI device power management fixes (Rafael J Wysocki). - assorted cleanups related to ACPI (Dominik Brodowski, Fabian Frederick, Lorenzo Pieralisi, Mathias Krause, Rafael J Wysocki). - fix for a long-standing issue causing General Protection Faults to be generated occasionally on return to user space after resume from ACPI-based suspend-to-RAM on 32-bit x86 (Ingo Molnar). - fix to make the suspend core code return -EBUSY consistently in all cases when system suspend is aborted due to wakeup detection (Ruchi Kandoi). - support for automated device wakeup IRQ handling allowing drivers to make their PM support more starightforward (Tony Lindgren). - new tracepoints for suspend-to-idle tracing and rework of the prepare/complete callbacks tracing in the PM core (Todd E Brandt, Rafael J Wysocki). - wakeup sources framework enhancements (Jin Qian). - new macro for noirq system PM callbacks (Grygorii Strashko). - assorted cleanups related to system suspend (Rafael J Wysocki). - cpuidle core cleanups to make the code more efficient (Rafael J Wysocki). - powernv/pseries cpuidle driver update (Shilpasri G Bhat). - cpufreq core fixes related to CPU online/offline that should reduce the overhead of these operations quite a bit, unless the CPU in question is physically going away (Viresh Kumar, Saravana Kannan). - serialization of cpufreq governor callbacks to avoid race conditions in some cases (Viresh Kumar). - intel_pstate driver fixes and cleanups (Doug Smythies, Prarit Bhargava, Joe Konno). - cpufreq driver (arm_big_little, cpufreq-dt, qoriq) updates (Sudeep Holla, Felipe Balbi, Tang Yuantian). - assorted cleanups in cpufreq drivers and core (Shailendra Verma, Fabian Frederick, Wang Long). - new Device Tree bindings for representing Operating Performance Points (Viresh Kumar). - updates for the common clock operations support code in the PM core (Rajendra Nayak, Geert Uytterhoeven). - PM domains core code update (Geert Uytterhoeven). - Intel Knights Landing support for the RAPL (Running Average Power Limit) power capping driver (Dasaratharaman Chandramouli). - fixes related to the floor frequency setting on Atom SoCs in the RAPL power capping driver (Ajay Thomas). - runtime PM framework documentation update (Ben Dooks). - cpupower tool fix (Herton R Krzesinski)" * tag 'pm+acpi-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (194 commits) cpuidle: powernv/pseries: Auto-promotion of snooze to deeper idle state x86: Load __USER_DS into DS/ES after resume PM / OPP: Add binding for 'opp-suspend' PM / OPP: Allow multiple OPP tables to be passed via DT PM / OPP: Add new bindings to address shortcomings of existing bindings ACPI: Constify ACPI device IDs in documentation ACPI / enumeration: Document the rules regarding the PRP0001 device ID ACPI / video: Make acpi_video_unregister_backlight() private acpi-video-detect: Remove old API toshiba-acpi: Port to new backlight interface selection API thinkpad-acpi: Port to new backlight interface selection API sony-laptop: Port to new backlight interface selection API samsung-laptop: Port to new backlight interface selection API msi-wmi: Port to new backlight interface selection API msi-laptop: Port to new backlight interface selection API intel-oaktrail: Port to new backlight interface selection API ideapad-laptop: Port to new backlight interface selection API fujitsu-laptop: Port to new backlight interface selection API eeepc-laptop: Port to new backlight interface selection API dell-wmi: Port to new backlight interface selection API ...
2015-06-23Merge branch 'timers-core-for-linus' of ↵Linus Torvalds22-1061/+1018
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "A rather largish update for everything time and timer related: - Cache footprint optimizations for both hrtimers and timer wheel - Lower the NOHZ impact on systems which have NOHZ or timer migration disabled at runtime. - Optimize run time overhead of hrtimer interrupt by making the clock offset updates smarter - hrtimer cleanups and removal of restrictions to tackle some problems in sched/perf - Some more leap second tweaks - Another round of changes addressing the 2038 problem - First step to change the internals of clock event devices by introducing the necessary infrastructure - Allow constant folding for usecs/msecs_to_jiffies() - The usual pile of clockevent/clocksource driver updates The hrtimer changes contain updates to sched, perf and x86 as they depend on them plus changes all over the tree to cleanup API changes and redundant code, which got copied all over the place. The y2038 changes touch s390 to remove the last non 2038 safe code related to boot/persistant clock" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (114 commits) clocksource: Increase dependencies of timer-stm32 to limit build wreckage timer: Minimize nohz off overhead timer: Reduce timer migration overhead if disabled timer: Stats: Simplify the flags handling timer: Replace timer base by a cpu index timer: Use hlist for the timer wheel hash buckets timer: Remove FIFO "guarantee" timers: Sanitize catchup_timer_jiffies() usage hrtimer: Allow hrtimer::function() to free the timer seqcount: Introduce raw_write_seqcount_barrier() seqcount: Rename write_seqcount_barrier() hrtimer: Fix hrtimer_is_queued() hole hrtimer: Remove HRTIMER_STATE_MIGRATE selftest: Timers: Avoid signal deadlock in leap-a-day timekeeping: Copy the shadow-timekeeper over the real timekeeper last clockevents: Check state instead of mode in suspend/resume path selftests: timers: Add leap-second timer edge testing to leap-a-day.c ntp: Do leapsecond adjustment in adjtimex read path time: Prevent early expiry of hrtimers[CLOCK_REALTIME] at the leap second edge ntp: Introduce and use SECS_PER_DAY macro instead of 86400 ...
2015-06-19timer: Minimize nohz off overheadThomas Gleixner4-8/+17
If nohz is disabled on the kernel command line the [hr]timer code still calls wake_up_nohz_cpu() and tick_nohz_full_cpu(), a pretty pointless exercise. Cache nohz_active in [hr]timer per cpu bases and avoid the overhead. Before: 48.10% hog [.] main 15.25% [kernel] [k] _raw_spin_lock_irqsave 9.76% [kernel] [k] _raw_spin_unlock_irqrestore 6.50% [kernel] [k] mod_timer 6.44% [kernel] [k] lock_timer_base.isra.38 3.87% [kernel] [k] detach_if_pending 3.80% [kernel] [k] del_timer 2.67% [kernel] [k] internal_add_timer 1.33% [kernel] [k] __internal_add_timer 0.73% [kernel] [k] timerfn 0.54% [kernel] [k] wake_up_nohz_cpu After: 48.73% hog [.] main 15.36% [kernel] [k] _raw_spin_lock_irqsave 9.77% [kernel] [k] _raw_spin_unlock_irqrestore 6.61% [kernel] [k] lock_timer_base.isra.38 6.42% [kernel] [k] mod_timer 3.90% [kernel] [k] detach_if_pending 3.76% [kernel] [k] del_timer 2.41% [kernel] [k] internal_add_timer 1.39% [kernel] [k] __internal_add_timer 0.76% [kernel] [k] timerfn We probably should have a cached value for nohz full in the per cpu bases as well to avoid the cpumask check. The base cache line is hot already, the cpumask not necessarily. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Joonwoo Park <joonwoop@codeaurora.org> Cc: Wenbo Wang <wenbo.wang@memblaze.com> Link: http://lkml.kernel.org/r/20150526224512.207378134@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-06-19timer: Reduce timer migration overhead if disabledThomas Gleixner5-26/+109
Eric reported that the timer_migration sysctl is not really nice performance wise as it needs to check at every timer insertion whether the feature is enabled or not. Further the check does not live in the timer code, so we have an extra function call which checks an extra cache line to figure out that it is disabled. We can do better and store that information in the per cpu (hr)timer bases. I pondered to use a static key, but that's a nightmare to update from the nohz code and the timer base cache line is hot anyway when we select a timer base. The old logic enabled the timer migration unconditionally if CONFIG_NO_HZ was set even if nohz was disabled on the kernel command line. With this modification, we start off with migration disabled. The user visible sysctl is still set to enabled. If the kernel switches to NOHZ migration is enabled, if the user did not disable it via the sysctl prior to the switch. If nohz=off is on the kernel command line, migration stays disabled no matter what. Before: 47.76% hog [.] main 14.84% [kernel] [k] _raw_spin_lock_irqsave 9.55% [kernel] [k] _raw_spin_unlock_irqrestore 6.71% [kernel] [k] mod_timer 6.24% [kernel] [k] lock_timer_base.isra.38 3.76% [kernel] [k] detach_if_pending 3.71% [kernel] [k] del_timer 2.50% [kernel] [k] internal_add_timer 1.51% [kernel] [k] get_nohz_timer_target 1.28% [kernel] [k] __internal_add_timer 0.78% [kernel] [k] timerfn 0.48% [kernel] [k] wake_up_nohz_cpu After: 48.10% hog [.] main 15.25% [kernel] [k] _raw_spin_lock_irqsave 9.76% [kernel] [k] _raw_spin_unlock_irqrestore 6.50% [kernel] [k] mod_timer 6.44% [kernel] [k] lock_timer_base.isra.38 3.87% [kernel] [k] detach_if_pending 3.80% [kernel] [k] del_timer 2.67% [kernel] [k] internal_add_timer 1.33% [kernel] [k] __internal_add_timer 0.73% [kernel] [k] timerfn 0.54% [kernel] [k] wake_up_nohz_cpu Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Joonwoo Park <joonwoop@codeaurora.org> Cc: Wenbo Wang <wenbo.wang@memblaze.com> Link: http://lkml.kernel.org/r/20150526224512.127050787@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-06-19timer: Stats: Simplify the flags handlingThomas Gleixner2-10/+7
Simplify the handling of the flag storage for the timer statistics. No intermediate storage anymore. Just hand over the flags field. I left the printout of 'deferrable' for now because changing this would be an ABI update and I have no idea how strong people feel about that. OTOH, I wonder whether we should kill the whole timer stats stuff because all of that information can be retrieved via ftrace/perf as well. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Joonwoo Park <joonwoop@codeaurora.org> Cc: Wenbo Wang <wenbo.wang@memblaze.com> Link: http://lkml.kernel.org/r/20150526224512.046626248@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-06-19timer: Replace timer base by a cpu indexThomas Gleixner1-91/+36
Instead of storing a pointer to the per cpu tvec_base we can simply cache a CPU index in the timer_list and use that to get hold of the correct per cpu tvec_base. This is only used in lock_timer_base() and the slightly larger code is peanuts versus the spinlock operation and the d-cache foot print of the timer wheel. Aside of that this allows to get rid of following nuisances: - boot_tvec_base That statically allocated 4k bss data is just kept around so the timer has a home when it gets statically initialized. It serves no other purpose. With the CPU index we assign the timer to CPU0 at static initialization time and therefor can avoid the whole boot_tvec_base dance. That also simplifies the init code, which just can use the per cpu base. Before: text data bss dec hex filename 17491 9201 4160 30852 7884 ../build/kernel/time/timer.o After: text data bss dec hex filename 17440 9193 0 26633 6809 ../build/kernel/time/timer.o - Overloading the base pointer with various flags The CPU index has enough space to hold the flags (deferrable, irqsafe) so we can get rid of the extra masking and bit fiddling with the base pointer. As a benefit we reduce the size of struct timer_list on 64 bit machines. 4 - 8 bytes, a size reduction up to 15% per struct timer_list, which is a real win as we have tons of them embedded in other structs. This changes also the newly added deferrable printout of the timer start trace point to capture and print all timer->flags, which allows us to decode the target cpu of the timer as well. We might have used bitfields for this, but that would change the static initializers and the init function for no value to accomodate big endian bitfields. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Joonwoo Park <joonwoop@codeaurora.org> Cc: Wenbo Wang <wenbo.wang@memblaze.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Badhri Jagan Sridharan <Badhri@google.com> Link: http://lkml.kernel.org/r/20150526224511.950084301@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-06-19timer: Use hlist for the timer wheel hash bucketsThomas Gleixner1-37/+27
This reduces the size of struct tvec_base by 50% and results in slightly smaller code as well. Before: struct tvec_base: size: 8256, cachelines: 129 text data bss dec hex filename 17698 13297 8256 39251 9953 ../build/kernel/time/timer.o After: struct tvec_base: 4160, cachelines: 65 text data bss dec hex filename 17491 9201 4160 30852 7884 ../build/kernel/time/timer.o Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Joonwoo Park <joonwoop@codeaurora.org> Cc: Wenbo Wang <wenbo.wang@memblaze.com> Link: http://lkml.kernel.org/r/20150526224511.854731214@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-06-19timer: Remove FIFO "guarantee"Thomas Gleixner1-4/+2
The FIFO guarantee is only there if two timers are queued into the same bucket at the same jiffie on the same cpu: - The slack value depends on the delta between expiry and enqueue time, so the resulting expiry time can be different for timers which are queued in different jiffies. - Timers which are queued into the secondary array end up after a later queued timer which was queued into the primary array due to cascading. - Timers can end up on different cpus due to the NOHZ target moving around. Obviously there is no guarantee of expiry ordering between cpus. So anything which relies on FIFO behaviour of the timer wheel is broken already. This is a preparatory patch for converting the timer wheel to hlist which reduces the memory foot print of the wheel by 50%. It's a seperate patch so any (unlikely to happen) regression caused by this can be identified clearly. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Joonwoo Park <joonwoop@codeaurora.org> Cc: Wenbo Wang <wenbo.wang@memblaze.com> Cc: George Spelvin <linux@horizon.com> Link: http://lkml.kernel.org/r/20150526224511.757520403@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-06-19timers: Sanitize catchup_timer_jiffies() usageThomas Gleixner1-24/+16
catchup_timer_jiffies() has been applied blindly to several functions without looking for possible better ways to do it. 1) internal_add_timer() Move the update to base->all_timers before we actually insert the timer into the wheel. 2) detach_if_pending() Again the update to base->all_timers allows us to explicitely do the timer_jiffies update in place, if this was the last timer which got removed. 3) __run_timers() We only check on entry, which is silly, because base->timer_jiffies can be behind - especially on NOHZ kernels - and if there is a single deferrable timer somewhere between base->timer_jiffies and jiffies we expire it and then loop until base->timer_jiffies == jiffies. Move it into the loop. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Joonwoo Park <joonwoop@codeaurora.org> Cc: Wenbo Wang <wenbo.wang@memblaze.com> Link: http://lkml.kernel.org/r/20150526224511.662994644@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-06-19Merge branches 'pm-sleep' and 'pm-runtime'Rafael J. Wysocki1-4/+13
* pm-sleep: PM / sleep: trace_device_pm_callback coverage in dpm_prepare/complete PM / wakeup: add a dummy wakeup_source to record statistics PM / sleep: Make suspend-to-idle-specific code depend on CONFIG_SUSPEND PM / sleep: Return -EBUSY from suspend_enter() on wakeup detection PM / tick: Add tracepoints for suspend-to-idle diagnostics PM / sleep: Fix symbol name in a comment in kernel/power/main.c leds / PM: fix hibernation on arm when gpio-led used with CPU led trigger ARM: omap-device: use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS bus: omap_l3_noc: add missed callbacks for suspend-to-disk PM / sleep: Add macro to define common noirq system PM callbacks PM / sleep: Refine diagnostic messages in enter_state() PM / wakeup: validate wakeup source before activating it. * pm-runtime: PM / Runtime: Update last_busy in rpm_resume PM / runtime: add note about re-calling in during device probe()
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