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2015-10-22time: Fix timekeeping_freqadjust()'s incorrect use of abs() instead of abs64()John Stultz
commit 2619d7e9c92d524cb155ec89fd72875321512e5b upstream. The internal clocksteering done for fine-grained error correction uses a logarithmic approximation, so any time adjtimex() adjusts the clock steering, timekeeping_freqadjust() quickly approximates the correct clock frequency over a series of ticks. Unfortunately, the logic in timekeeping_freqadjust(), introduced in commit: dc491596f639 ("timekeeping: Rework frequency adjustments to work better w/ nohz") used the abs() function with a s64 error value to calculate the size of the approximated adjustment to be made. Per include/linux/kernel.h: "abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()". Thus on 32-bit platforms, this resulted in the clocksteering to take a quite dampended random walk trying to converge on the proper frequency, which caused the adjustments to be made much slower then intended (most easily observed when large adjustments are made). This patch fixes the issue by using abs64() instead. Reported-by: Nuno Gonçalves <nunojpg@gmail.com> Tested-by: Nuno Goncalves <nunojpg@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Miroslav Lichvar <mlichvar@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1441840051-20244-1-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-13ktime: Fix ktime_divns to do signed divisionJohn Stultz
It was noted that the 32bit implementation of ktime_divns() was doing unsigned division and didn't properly handle negative values. And when a ktime helper was changed to utilize ktime_divns, it caused a regression on some IR blasters. See the following bugzilla for details: https://bugzilla.redhat.com/show_bug.cgi?id=1200353 This patch fixes the problem in ktime_divns by checking and preserving the sign bit, and then reapplying it if appropriate after the division, it also changes the return type to a s64 to make it more obvious this is expected. Nicolas also pointed out that negative dividers would cause infinite loops on 32bit systems, negative dividers is unlikely for users of this function, but out of caution this patch adds checks for negative dividers for both 32-bit (BUG_ON) and 64-bit(WARN_ON) versions to make sure no such use cases creep in. [ tglx: Hand an u64 to do_div() to avoid the compiler warning ] Fixes: 166afb64511e 'ktime: Sanitize ktime_to_us/ms conversion' Reported-and-tested-by: Trevor Cordes <trevor@tecnopolis.ca> Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Boyer <jwboyer@redhat.com> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/1431118043-23452-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-09Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Thomas Gleixner: "A simple fix to actually shut down a detached device instead of keeping it active" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clockevents: Shutdown detached clockevent device
2015-04-24clockevents: Shutdown detached clockevent deviceViresh Kumar
A clockevent device is marked DETACHED when it is replaced by another clockevent device. The device is shutdown properly for drivers that implement legacy ->set_mode() callback, as we call ->set_mode() for CLOCK_EVT_MODE_UNUSED as well. But for the new per-state callback interface, we skip shutting down the device, as we thought its an internal state change. That wasn't correct. The effect is that the device is left programmed in oneshot or periodic mode. Fall-back to 'case CLOCK_EVT_STATE_SHUTDOWN', to shutdown the device. Fixes: bd624d75db21 "clockevents: Introduce mode specific callbacks" Reported-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: linaro-kernel@lists.linaro.org Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/eef0a91c51b74d4e52c8e5a95eca27b5a0563f07.1428650683.git.viresh.kumar@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-21Merge tag 'char-misc-4.1-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver updates from Greg KH: "Here's the big char/misc driver patchset for 4.1-rc1. Lots of different driver subsystem updates here, nothing major, full details are in the shortlog. All of this has been in linux-next for a while" * tag 'char-misc-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (133 commits) mei: trace: remove unused TRACE_SYSTEM_STRING DTS: ARM: OMAP3-N900: Add lis3lv02d support Documentation: DT: lis302: update wakeup binding lis3lv02d: DT: add wakeup unit 2 and wakeup threshold lis3lv02d: DT: use s32 to support negative values Drivers: hv: hv_balloon: correctly handle num_pages>INT_MAX case Drivers: hv: hv_balloon: correctly handle val.freeram<num_pages case mei: replace check for connection instead of transitioning mei: use mei_cl_is_connected consistently mei: fix mei_poll operation hv_vmbus: Add gradually increased delay for retries in vmbus_post_msg() Drivers: hv: hv_balloon: survive ballooning request with num_pages=0 Drivers: hv: hv_balloon: eliminate jumps in piecewiese linear floor function Drivers: hv: hv_balloon: do not online pages in offline blocks hv: remove the per-channel workqueue hv: don't schedule new works in vmbus_onoffer()/vmbus_onoffer_rescind() hv: run non-blocking message handlers in the dispatch tasklet coresight: moving to new "hwtracing" directory coresight-tmc: Adding a status interface to sysfs coresight: remove the unnecessary configuration coresight-default-sink ...
2015-04-03timers/PM: Drop unnecessary braces from tick_freeze()Rafael J. Wysocki
Some braces in tick_freeze() are not necessary, so drop them. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: peterz@infradead.org Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1534128.H5hN3KBFB4@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03timers/PM: Fix up tick_unfreeze()Rafael J. Wysocki
A recent conflict resolution has left tick_resume() in tick_unfreeze() which leads to an unbalanced execution of tick_resume_broadcast() every time that function runs. Fix that by replacing the tick_resume() in tick_unfreeze() with tick_resume_local() as appropriate. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: boris.ostrovsky@oracle.com Cc: david.vrabel@citrix.com Cc: konrad.wilk@oracle.com Cc: peterz@infradead.org Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/8099075.V0LvN3pQAV@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03timekeeping: Get rid of stale commentThomas Gleixner
Arch specific management of xtime/jiffies/wall_to_monotonic is gone for quite a while. Zap the stale comment. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/2422730.dmO29q661S@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03clockevents: Cleanup dead cpu explicitelyThomas Gleixner
clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the cleanup function for a dead cpu and invoke it directly from the cpu down code. Make it conditional on CPU_HOTPLUG as well. Temporary change, will be refined in the future. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Rebased, added clockevents_notify() removal ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1735025.raBZdQHM3m@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03clockevents: Make tick handover explicitThomas Gleixner
clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the tick_handover call and invoke it explicitely from the hotplug code. Temporary solution will be cleaned up in later patches. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Rebase ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1658173.RkEEILFiQZ@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03clockevents: Remove broadcast oneshot control leftoversRafael J. Wysocki
Now that all users are converted over to explicit calls into the clockevents state machine, remove the notification chain leftovers. Original-from: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/14018863.NQUzkFuafr@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03clockevents: Provide explicit broadcast oneshot control functionsThomas Gleixner
clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the broadcast oneshot control into a separate function and provide inline helpers. Switch clockevents_notify() over. This will go away once all callers are converted. This also gets rid of the nested locking of clockevents_lock and broadcast_lock. The broadcast oneshot control functions do not require clockevents_lock. Only the managing functions (setup/shutdown/suspend/resume of the broadcast device require clockevents_lock. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Alexandre Courbot <gnurou@gmail.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Tony Lindgren <tony@atomide.com> Link: http://lkml.kernel.org/r/13000649.8qZuEDV0OA@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03clockevents: Remove the broadcast control leftoversThomas Gleixner
All users converted. Remove the notify leftovers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/2076318.76XJZ8QYP3@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03clockevents: Provide explicit broadcast control functionsThomas Gleixner
clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the broadcast control into a separate function and provide inline helpers. Switch clockevents_notify() over. This will go away once all callers are converted. This also gets rid of the nested locking of clockevents_lock and broadcast_lock. The broadcast control functions do not require clockevents_lock. Only the managing functions (setup/shutdown/suspend/resume of the broadcast device require clockevents_lock. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tony Lindgren <tony@atomide.com> Link: http://lkml.kernel.org/r/8086559.ttsuS0n1Xr@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03clocksource: Improve comment explaining clocks_calc_max_nsecs()'s 50% safety ↵John Stultz
margin Ingo noted that the description of clocks_calc_max_nsecs()'s 50% safety margin was somewhat circular. So this patch tries to improve the comment to better explain what we mean by the 50% safety margin and why we need it. Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1427945681-29972-20-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03time, drivers/rtc: Don't bother with rtc_resume() for the nonstop clocksourceXunlei Pang
If a system does not provide a persistent_clock(), the time will be updated on resume by rtc_resume(). With the addition of the non-stop clocksources for suspend timing, those systems set the time on resume in timekeeping_resume(), but may not provide a valid persistent_clock(). This results in the rtc_resume() logic thinking no one has set the time and it then will over-write the suspend time again, which is not necessary and only increases clock error. So, fix this for rtc_resume(). This patch also improves the name of persistent_clock_exist to make it more grammatical. Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1427945681-29972-19-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03time: Fix a bug in timekeeping_suspend() with no persistent clockXunlei Pang
When there's no persistent clock, normally timekeeping_suspend_time should always be zero, but this can break in timekeeping_suspend(). At T1, there was a system suspend, so old_delta was assigned T1. After some time, one time adjustment happened, and xtime got the value of T1-dt(0s<dt<2s). Then, there comes another system suspend soon after this adjustment, obviously we will get a small negative delta_delta, resulting in a negative timekeeping_suspend_time. This is problematic, when doing timekeeping_resume() if there is no nonstop clocksource for example, it will hit the else leg and inject the improper sleeptime which is the wrong logic. So, we can solve this problem by only doing delta related code when the persistent clock is existent. Actually the code only makes sense for persistent clock cases. Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1427945681-29972-18-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03time: Don't build timekeeping_inject_sleeptime64() if no one uses itXunlei Pang
timekeeping_inject_sleeptime64() is only used by RTC suspend/resume, so add build dependencies on the necessary RTC related macros. Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> [ Improve commit message clarity. ] Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1427945681-29972-16-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03time: Add y2038 safe update_persistent_clock64()Xunlei Pang
As part of addressing in-kernel y2038 issues, this patch adds update_persistent_clock64() and replaces all the call sites of update_persistent_clock() with this function. This is a __weak implementation, which simply calls the existing y2038 unsafe update_persistent_clock(). This allows architecture specific implementations to be converted independently, and eventually y2038-unsafe update_persistent_clock() can be removed after all its architecture specific implementations have been converted to update_persistent_clock64(). Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1427945681-29972-4-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03time: Add y2038 safe read_persistent_clock64()Xunlei Pang
As part of addressing in-kernel y2038 issues, this patch adds read_persistent_clock64() and replaces all the call sites of read_persistent_clock() with this function. This is a __weak implementation, which simply calls the existing y2038 unsafe read_persistent_clock(). This allows architecture specific implementations to be converted independently, and eventually the y2038 unsafe read_persistent_clock() can be removed after all its architecture specific implementations have been converted to read_persistent_clock64(). Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1427945681-29972-3-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03time: Add y2038 safe read_boot_clock64()Xunlei Pang
As part of addressing in-kernel y2038 issues, this patch adds read_boot_clock64() and replaces all the call sites of read_boot_clock() with this function. This is a __weak implementation, which simply calls the existing y2038 unsafe read_boot_clock(). This allows architecture specific implementations to be converted independently, and eventually the y2038 unsafe read_boot_clock() can be removed after all its architecture specific implementations have been converted to read_boot_clock64(). Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1427945681-29972-2-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-02timer: Further simplify the SMP and HOTPLUG logicPeter Zijlstra
Remove one CONFIG_HOTPLUG_CPU #ifdef in trade for introducing one CONFIG_SMP #ifdef. The CONFIG_SMP ifdef avoids declaring the per-CPU __tvec_bases storage on UP systems since they already have boot_tvec_bases. Also (re)add a runtime check on the base alignment -- for the paranoid amongst us :-) Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/fdd2d35e169bdc554ffa3fe77f77716298c75ada.1427814611.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-02timer: Don't initialize 'tvec_base' on hotplugViresh Kumar
There is no need to call init_timers_cpu() on every CPU hotplug event, there is not much we need to reset. - Timer-lists are already empty at the end of migrate_timers(). - timer_jiffies will be refreshed while adding a new timer, after the CPU is online again. - active_timers and all_timers can be reset from migrate_timers(). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/54a1c30ea7b805af55beb220cadf5a07a21b0a4d.1427814611.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-02timer: Allocate per-cpu tvec_base's staticallyPeter Zijlstra
Memory for the 'tvec_base' array is allocated separately for the boot CPU (statically) and non-boot CPUs (dynamically). The reason is because __TIMER_INITIALIZER() needs to set ->base to a valid pointer (because we've made NULL special, hint: lock_timer_base()) and we cannot get a compile time pointer to per-cpu entries because we don't know where we'll map the section, even for the boot cpu. This can be simplified a bit by statically allocating per-cpu memory. The only disadvantage is that memory for one of the structures will stay unused, i.e. for the boot CPU, which uses boot_tvec_bases. This will also guarantee that tvec_base is cacheline aligned. Even though tvec_base has ____cacheline_aligned stuck on, kzalloc_node() does not actually respect that (but guarantees a minimum u64 alignment). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/17cdf560f2727f687ab159707d0aa591f8a2f82d.1427814611.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-02clockevents: Fix cpu_down() race for hrtimer based broadcastingPreeti U Murthy
It was found when doing a hotplug stress test on POWER, that the machine either hit softlockups or rcu_sched stall warnings. The issue was traced to commit: 7cba160ad789 ("powernv/cpuidle: Redesign idle states management") which exposed the cpu_down() race with hrtimer based broadcast mode: 5d1638acb9f6 ("tick: Introduce hrtimer based broadcast") The race is the following: Assume CPU1 is the CPU which holds the hrtimer broadcasting duty before it is taken down. CPU0 CPU1 cpu_down() take_cpu_down() disable_interrupts() cpu_die() while (CPU1 != CPU_DEAD) { msleep(100); switch_to_idle(); stop_cpu_timer(); schedule_broadcast(); } tick_cleanup_cpu_dead() take_over_broadcast() So after CPU1 disabled interrupts it cannot handle the broadcast hrtimer anymore, so CPU0 will be stuck forever. Fix this by explicitly taking over broadcast duty before cpu_die(). This is a temporary workaround. What we really want is a callback in the clockevent device which allows us to do that from the dying CPU by pushing the hrtimer onto a different cpu. That might involve an IPI and is definitely more complex than this immediate fix. Changelog was picked up from: https://lkml.org/lkml/2015/2/16/213 Suggested-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: mpe@ellerman.id.au Cc: nicolas.pitre@linaro.org Cc: peterz@infradead.org Cc: rjw@rjwysocki.net Fixes: http://linuxppc.10917.n7.nabble.com/offlining-cpus-breakage-td88619.html Link: http://lkml.kernel.org/r/20150330092410.24979.59887.stgit@preeti.in.ibm.com [ Merged it to the latest timer tree, renamed the callback, tidied up the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-02tick: Further simplify tick-internal.hIngo Molnar
Move the broadcasting related section to the GENERIC_CLOCKEVENTS=y section - this also solves build failures on architectures that don't use generic clockevents yet. Also standardize include file style to make it easier to read, and use nesting depth aware preprocessor directives to make future merges easier. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-01arm/bL_switcher: Kill tick suspend hackeryThomas Gleixner
Use the new tick_suspend/resume_local() and get rid of the homebrewn implementation of these in the ARM bL switcher. The check for the cpumask is completely pointless. There is no harm to suspend a per cpu tick device unconditionally. If that's a real issue then we fix it proper at the core level and not with some completely undocumented hacks in some random core code. Move the tick internals to the core code, now that this nuisance is gone. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ rjw: Rebase, changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Link: http://lkml.kernel.org/r/1655112.Ws17YsMfN7@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-01tick/xen: Provide and use tick_suspend_local() and tick_resume_local()Thomas Gleixner
Xen calls on every cpu into tick_resume() which is just wrong. tick_resume() is for the syscore global suspend/resume invocation. What XEN really wants is a per cpu local resume function. Provide a tick_resume_local() function and use it in XEN. Also provide a complementary tick_suspend_local() and modify tick_unfreeze() and tick_freeze(), respectively, to use the new local tick resume/suspend functions. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Combined two patches, rebased, modified subject/changelog. ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1698741.eezk9tnXtG@vostro.rjw.lan [ Merged to latest timers/core. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-01tick: Make tick_resume_broadcast_oneshot() staticThomas Gleixner
Solely used in tick-broadcast.c and the return value is hardcoded 0. Make it static and void. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1689058.QkHYDJSRKu@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-01clockevents: Make suspend/resume calls explicitThomas Gleixner
clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the suspend/resume() calls and invoke them directly from the call sites. No locking required at this point because these calls happen with interrupts disabled and a single cpu online. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Rebased on top of 4.0-rc5. ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/713674030.jVm1qaHuPf@vostro.rjw.lan [ Rebased on top of latest timers/core. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-01clockevents: Remove extra local_irq_save() in clockevents_exchange_device()Thomas Gleixner
Called with 'clockevents_lock' held and interrupts disabled already. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/51005827.yXt5tjZMBs@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-01tick: Move core only declarations and functions to coreThomas Gleixner
No point to expose everything to the world. People just believe such functions can be abused for whatever purposes. Sigh. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Rebased on top of 4.0-rc5 ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Nicolas Pitre <nico@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/28017337.VbCUc39Gme@vostro.rjw.lan [ Merged to latest timers/core ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-01tick: Simplify tick-internal.hThomas Gleixner
tick-internal.h is pretty confusing as a lot of the stub inlines are there several times. Distangle the maze and make clear functional sections. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/16068264.vcNp79HLaT@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-01tick: Move clocksource related stuff to timekeeping.hThomas Gleixner
Move clocksource related stuff to timekeeping.h and remove the pointless include from ntp.c Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/2714218.nM5AEfAHj0@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-01clockevents: Remove CONFIG_GENERIC_CLOCKEVENTS_BUILDThomas Gleixner
This option was for simpler migration to the clock events code. Most architectures have been converted and the option has been disfunctional as a standalone option for quite some time. Remove it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/5021859.jl9OC1medj@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-31Merge tag 'v4.0-rc6' into timers/core, before applying new patchesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27clockevents: Don't validate dev->mode against CLOCK_EVT_MODE_UNUSED for new ↵Viresh Kumar
interface It was a requirement in the legacy interface that drivers must initialize ->mode field to 'CLOCK_EVT_MODE_UNUSED'. This field isn't used anymore by the new interface and so should be only checked for the legacy interface. Probably it can be dropped as well as core doesn't rely on it anymore, but lets keep it to support legacy interface. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: linaro-kernel@lists.linaro.org Cc: linaro-networking@linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/c6604fa1a77fe1fc8dcab87769857228fb1dadd5.1425037853.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27clockevents: Manage device's state separately for the coreViresh Kumar
'enum clock_event_mode' is used for two purposes today: - to pass mode to the driver of clockevent device::set_mode(). - for managing state of the device for clockevents core. For supporting new modes/states we have moved away from the legacy set_mode() callback to new per-mode/state callbacks. New modes/states shouldn't be exposed to the legacy (now OBSOLOTE) callbacks and so we shouldn't add new states to 'enum clock_event_mode'. Lets have separate enums for the two use cases mentioned above. Keep using the earlier enum for legacy set_mode() callback and mark it OBSOLETE. And add another enum to clearly specify the possible states of a clockevent device. This also renames the newly added per-mode callbacks to reflect state changes. We haven't got rid of 'mode' member of 'struct clock_event_device' as it is used by some of the clockevent drivers and it would automatically die down once we migrate those drivers to the new interface. It ('mode') is only updated now for the drivers using the legacy interface. Suggested-by: Peter Zijlstra <peterz@infradead.org> Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: linaro-kernel@lists.linaro.org Cc: linaro-networking@linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/b6b0143a8a57bd58352ad35e08c25424c879c0cb.1425037853.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27clockevents: Handle tick device's resume separatelyViresh Kumar
Upcoming patch will redefine possible states of a clockevent device. The RESUME mode is a special case only for tick's clockevent devices. In future it can be replaced by ->resume() callback already available for clockevent devices. Lets handle it separately so that clockevents_set_mode() only handles states valid across all devices. This also renames set_mode_resume() to tick_resume() to make it more explicit. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: linaro-kernel@lists.linaro.org Cc: linaro-networking@linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/c1b0112410870f49e7bf06958e1483eac6c15e20.1425037853.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27time: Introduce tk_fast_rawPeter Zijlstra
Add the NMI safe CLOCK_MONOTONIC_RAW accessor.. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150319093400.562746929@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27time: Parametrize all tk_fast_mono usersPeter Zijlstra
In preparation for more tk_fast instances, remove all hard-coded tk_fast_mono references. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150319093400.484279927@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27time: Add timerkeeper::tkr_rawPeter Zijlstra
Introduce tkr_raw and make use of it. base_raw -> tkr_raw.base clock->{mult,shift} -> tkr_raw.{mult.shift} Kill timekeeping_get_ns_raw() in favour of timekeeping_get_ns(&tkr_raw), this removes all mono_raw special casing. Duplicate the updates to tkr_mono.cycle_last into tkr_raw.cycle_last, both need the same value. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150319093400.422589590@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27time: Rename timekeeper::tkr to timekeeper::tkr_monoPeter Zijlstra
In preparation of adding another tkr field, rename this one to tkr_mono. Also rename tk_read_base::base_mono to tk_read_base::base, since the structure is not specific to CLOCK_MONOTONIC and the mono name got added to the tk_read_base instance. Lots of trivial churn. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150319093400.344679419@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27timers, sched/clock: Clean up the code a bitIngo Molnar
Trivial cleanups, to improve the readability of the generic sched_clock() code: - Improve and standardize comments - Standardize the coding style - Use vertical spacing where appropriate - etc. No code changed: md5: 19a053b31e0c54feaeff1492012b019a sched_clock.o.before.asm 19a053b31e0c54feaeff1492012b019a sched_clock.o.after.asm Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27timers, sched/clock: Avoid deadlock during read from NMIDaniel Thompson
Currently it is possible for an NMI (or FIQ on ARM) to come in and read sched_clock() whilst update_sched_clock() has locked the seqcount for writing. This results in the NMI handler locking up when it calls raw_read_seqcount_begin(). This patch fixes the NMI safety issues by providing banked clock data. This is a similar approach to the one used in Thomas Gleixner's 4396e058c52e("timekeeping: Provide fast and NMI safe access to CLOCK_MONOTONIC"). Suggested-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/1427397806-20889-6-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27timers, sched/clock: Remove redundant notrace from update functionDaniel Thompson
Currently update_sched_clock() is marked as notrace but this function is not called by ftrace. This is trivially fixed by removing the mark up. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/1427397806-20889-5-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27timers, sched/clock: Remove suspend from clock_read_data()Daniel Thompson
Currently cd.read_data.suspended is read by the hotpath function sched_clock(). This variable need not be accessed on the hotpath. In fact, once it is removed, we can remove the conditional branches from sched_clock() and install a dummy read_sched_clock function to suspend the clock. The new master copy of the function pointer (actual_read_sched_clock) is introduced and is used for all reads of the clock hardware except those within sched_clock itself. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/1427397806-20889-4-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27timers, sched/clock: Optimize cache line usageDaniel Thompson
Currently sched_clock(), a very hot code path, is not optimized to minimise its cache profile. In particular: 1. cd is not ____cacheline_aligned, 2. struct clock_data does not distinguish between hotpath and coldpath data, reducing locality of reference in the hotpath, 3. Some hotpath data is missing from struct clock_data and is marked __read_mostly (which more or less guarantees it will not share a cache line with cd). This patch corrects these problems by extracting all hotpath data into a separate structure and using ____cacheline_aligned to ensure the hotpath uses a single (64 byte) cache line. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/1427397806-20889-3-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-27timers, sched/clock: Match scope of read and write seqcountsDaniel Thompson
Currently the scope of the raw_write_seqcount_begin/end() in sched_clock_register() far exceeds the scope of the read section in sched_clock(). This gives the impression of safety during cursory review but achieves little. Note that this is likely to be a latent issue at present because sched_clock_register() is typically called before we enable interrupts, however the issue does risk bugs being needlessly introduced as the code evolves. This patch fixes the problem by increasing the scope of the read locking performed by sched_clock() to cover all data modified by sched_clock_register. We also improve clarity by moving writes to struct clock_data that do not impact sched_clock() outside of the critical section. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> [ Reworked it slightly to apply to tip/timers/core] Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/1427397806-20889-2-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23timers/tick/broadcast-hrtimer: Fix suspicious RCU usage in idle loopPreeti U Murthy
The hrtimer mode of broadcast queues hrtimers in the idle entry path so as to wakeup cpus in deep idle states. The associated call graph is : cpuidle_idle_call() |____ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, ....)) |_____tick_broadcast_set_event() |____clockevents_program_event() |____bc_set_next() The hrtimer_{start/cancel} functions call into tracing which uses RCU. But it is not legal to call into RCU in cpuidle because it is one of the quiescent states. Hence protect this region with RCU_NONIDLE which informs RCU that the cpu is momentarily non-idle. As an aside it is helpful to point out that the clock event device that is programmed here is not a per-cpu clock device; it is a pseudo clock device, used by the broadcast framework alone. The per-cpu clock device programming never goes through bc_set_next(). Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: linuxppc-dev@ozlabs.org Cc: mpe@ellerman.id.au Cc: tglx@linutronix.de Link: http://lkml.kernel.org/r/20150318104705.17763.56668.stgit@preeti.in.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>