user/sven/linux.git/kernel/time/hrtimer.c, branch v4.17.13

Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME

2018-04-26T12:53:32Z

Revert commits 92af4dcb4e1c ("tracing: Unify the "boot" and "mono" tracing clocks") 127bfa5f4342 ("hrtimer: Unify MONOTONIC and BOOTTIME clock behavior") 7250a4047aa6 ("posix-timers: Unify MONOTONIC and BOOTTIME clock behavior") d6c7270e913d ("timekeeping: Remove boot time specific code") f2d6fdbfd238 ("Input: Evdev - unify MONOTONIC and BOOTTIME clock behavior") d6ed449afdb3 ("timekeeping: Make the MONOTONIC clock behave like the BOOTTIME clock") 72199320d49d ("timekeeping: Add the new CLOCK_MONOTONIC_ACTIVE clock") As stated in the pull request for the unification of CLOCK_MONOTONIC and CLOCK_BOOTTIME, it was clear that we might have to revert the change. As reported by several folks systemd and other applications rely on the documented behaviour of CLOCK_MONOTONIC on Linux and break with the above changes. After resume daemons time out and other timeout related issues are observed. Rafael compiled this list: * systemd kills daemons on resume, after >WatchdogSec seconds of suspending (Genki Sky). [Verified that that's because systemd uses CLOCK_MONOTONIC and expects it to not include the suspend time.] * systemd-journald misbehaves after resume: systemd-journald[7266]: File /var/log/journal/016627c3c4784cd4812d4b7e96a34226/system.journal corrupted or uncleanly shut down, renaming and replacing. (Mike Galbraith). * NetworkManager reports "networking disabled" and networking is broken after resume 50% of the time (Pavel). [May be because of systemd.] * MATE desktop dims the display and starts the screensaver right after system resume (Pavel). * Full system hang during resume (me). [May be due to systemd or NM or both.] That happens on debian and open suse systems. It's sad, that these problems were neither catched in -next nor by those folks who expressed interest in this change. Reported-by: Rafael J. Wysocki Reported-by: Genki Sky , Reported-by: Pavel Machek Signed-off-by: Thomas Gleixner Cc: Dmitry Torokhov Cc: John Stultz Cc: Jonathan Corbet Cc: Kevin Easton Cc: Linus Torvalds Cc: Mark Salyzyn Cc: Michael Kerrisk Cc: Peter Zijlstra Cc: Petr Mladek Cc: Prarit Bhargava Cc: Sergey Senozhatsky Cc: Steven Rostedt

Merge branches 'pm-cpuidle' and 'pm-qos'

2018-04-11T11:22:46Z

* pm-cpuidle: tick-sched: avoid a maybe-uninitialized warning cpuidle: Add definition of residency to sysfs documentation time: hrtimer: Use timerqueue_iterate_next() to get to the next timer nohz: Avoid duplication of code related to got_idle_tick nohz: Gather tick_sched booleans under a common flag field cpuidle: menu: Avoid selecting shallow states with stopped tick cpuidle: menu: Refine idle state selection for running tick sched: idle: Select idle state before stopping the tick time: hrtimer: Introduce hrtimer_next_event_without() time: tick-sched: Split tick_nohz_stop_sched_tick() cpuidle: Return nohz hint from cpuidle_select() jiffies: Introduce USER_TICK_USEC and redefine TICK_USEC sched: idle: Do not stop the tick before cpuidle_idle_call() sched: idle: Do not stop the tick upfront in the idle loop time: tick-sched: Reorganize idle tick management code * pm-qos: PM / QoS: mark expected switch fall-throughs

time: hrtimer: Use timerqueue_iterate_next() to get to the next timer

2018-04-09T09:54:57Z

Use timerqueue_iterate_next() to get to the next timer in __hrtimer_next_event_base() without browsing the timerqueue details diredctly. No intentional changes in functionality. Suggested-by: Frederic Weisbecker Signed-off-by: Rafael J. Wysocki

time: hrtimer: Introduce hrtimer_next_event_without()

2018-04-07T16:49:54Z

The next set of changes will need to compute the time to the next hrtimer event over all hrtimers except for the scheduler tick one. To that end introduce a new helper function, hrtimer_next_event_without(), for computing the time until the next hrtimer event over all timers except for one and modify the underlying code in __hrtimer_next_event_base() to prepare it for being called by that new function. No intentional changes in functionality. Signed-off-by: Rafael J. Wysocki Acked-by: Peter Zijlstra (Intel) Reviewed-by: Frederic Weisbecker

hrtimer: Unify MONOTONIC and BOOTTIME clock behavior

2018-03-13T06:34:23Z

Now that th MONOTONIC and BOOTTIME clocks are indentical remove all the special casing. The user space visible interfaces still support both clocks, but their behavior is identical. Signed-off-by: Thomas Gleixner Cc: Dmitry Torokhov Cc: John Stultz Cc: Jonathan Corbet Cc: Kevin Easton Cc: Linus Torvalds Cc: Mark Salyzyn Cc: Michael Kerrisk Cc: Peter Zijlstra Cc: Petr Mladek Cc: Prarit Bhargava Cc: Sergey Senozhatsky Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20180301165150.410218515@linutronix.de Signed-off-by: Ingo Molnar

hrtimer: remove unneeded kallsyms include

2018-02-07T02:32:47Z

hrtimer does not seem to use any of kallsyms functions/defines. Link: http://lkml.kernel.org/r/20171208025616.16267-9-sergey.senozhatsky@gmail.com Signed-off-by: Sergey Senozhatsky Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'timers/urgent' into timers/core

2018-01-27T14:35:29Z

Pick up urgent bug fix and resolve the conflict. Signed-off-by: Thomas Gleixner

hrtimer: Reset hrtimer cpu base proper on CPU hotplug

2018-01-27T14:12:22Z

The hrtimer interrupt code contains a hang detection and mitigation mechanism, which prevents that a long delayed hrtimer interrupt causes a continous retriggering of interrupts which prevent the system from making progress. If a hang is detected then the timer hardware is programmed with a certain delay into the future and a flag is set in the hrtimer cpu base which prevents newly enqueued timers from reprogramming the timer hardware prior to the chosen delay. The subsequent hrtimer interrupt after the delay clears the flag and resumes normal operation. If such a hang happens in the last hrtimer interrupt before a CPU is unplugged then the hang_detected flag is set and stays that way when the CPU is plugged in again. At that point the timer hardware is not armed and it cannot be armed because the hang_detected flag is still active, so nothing clears that flag. As a consequence the CPU does not receive hrtimer interrupts and no timers expire on that CPU which results in RCU stalls and other malfunctions. Clear the flag along with some other less critical members of the hrtimer cpu base to ensure starting from a clean state when a CPU is plugged in. Thanks to Paul, Sebastian and Anna-Maria for their help to get down to the root cause of that hard to reproduce heisenbug. Once understood it's trivial and certainly justifies a brown paperbag. Fixes: 41d2e4949377 ("hrtimer: Tune hrtimer_interrupt hang logic") Reported-by: Paul E. McKenney Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: Sebastian Sewior Cc: Anna-Maria Gleixner Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801261447590.2067@nanos

hrtimer: Implement SOFT/HARD clock base selection

2018-01-16T08:51:22Z

All prerequisites to handle hrtimers for expiry in either hard or soft interrupt context are in place. Add the missing bit in hrtimer_init() which associates the timer to the hard or the softirq clock base. Signed-off-by: Anna-Maria Gleixner Cc: Christoph Hellwig Cc: John Stultz Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: keescook@chromium.org Link: http://lkml.kernel.org/r/20171221104205.7269-30-anna-maria@linutronix.de Signed-off-by: Ingo Molnar

hrtimer: Implement support for softirq based hrtimers

2018-01-16T08:51:22Z

hrtimer callbacks are always invoked in hard interrupt context. Several users in tree require soft interrupt context for their callbacks and achieve this by combining a hrtimer with a tasklet. The hrtimer schedules the tasklet in hard interrupt context and the tasklet callback gets invoked in softirq context later. That's suboptimal and aside of that the real-time patch moves most of the hrtimers into softirq context. So adding native support for hrtimers expiring in softirq context is a valuable extension for both mainline and the RT patch set. Each valid hrtimer clock id has two associated hrtimer clock bases: one for timers expiring in hardirq context and one for timers expiring in softirq context. Implement the functionality to associate a hrtimer with the hard or softirq related clock bases and update the relevant functions to take them into account when the next expiry time needs to be evaluated. Add a check into the hard interrupt context handler functions to check whether the first expiring softirq based timer has expired. If it's expired the softirq is raised and the accounting of softirq based timers to evaluate the next expiry time for programming the timer hardware is skipped until the softirq processing has finished. At the end of the softirq processing the regular processing is resumed. Suggested-by: Thomas Gleixner Suggested-by: Peter Zijlstra Signed-off-by: Anna-Maria Gleixner Cc: Christoph Hellwig Cc: John Stultz Cc: Linus Torvalds Cc: keescook@chromium.org Link: http://lkml.kernel.org/r/20171221104205.7269-29-anna-maria@linutronix.de Signed-off-by: Ingo Molnar