linux/kernel/time/sched_clock.c, branch v5.8

time/sched_clock: Expire timer in hardirq context

2020-03-19T08:45:08Z

To minimize latency, PREEMPT_RT kernels expires hrtimers in preemptible softirq context by default. This can be overriden by marking the timer's expiry with HRTIMER_MODE_HARD. sched_clock_timer is missing this annotation: if its callback is preempted and the duration of the preemption exceeds the wrap around time of the underlying clocksource, sched clock will get out of sync. Mark the sched_clock_timer for expiry in hard interrupt context. Signed-off-by: Ahmed S. Darwish Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200309181529.26558-1-a.darwish@linutronix.de

time/sched_clock: Disable interrupts in sched_clock_register()

2020-01-09T17:50:18Z

Instead of issueing a warning if sched_clock_register() is called from a context where IRQs are enabled, the code now ensures that IRQs are indeed disabled. Signed-off-by: Paul Cercueil Signed-off-by: Thomas Gleixner Acked-by: Daniel Lezcano Link: https://lore.kernel.org/r/20200107010630.954648-1-paul@crapouillou.net

timers/sched_clock: Include local timekeeping.h for missing declarations

2019-10-23T12:48:23Z

Include the timekeeping.h header to get the declaration of the sched_clock_{suspend,resume} functions. Fixes the following sparse warnings: kernel/time/sched_clock.c:275:5: warning: symbol 'sched_clock_suspend' was not declared. Should it be static? kernel/time/sched_clock.c:286:6: warning: symbol 'sched_clock_resume' was not declared. Should it be static? Signed-off-by: Ben Dooks (Codethink) Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20191022131226.11465-1-ben.dooks@codethink.co.uk

Merge tag 'printk-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk

2019-05-07T16:18:12Z

Pull printk updates from Petr Mladek: - Allow state reset of printk_once() calls. - Prevent crashes when dereferencing invalid pointers in vsprintf(). Only the first byte is checked for simplicity. - Make vsprintf warnings consistent and inlined. - Treewide conversion of obsolete %pf, %pF to %ps, %pF printf modifiers. - Some clean up of vsprintf and test_printf code. * tag 'printk-for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: lib/vsprintf: Make function pointer_string static vsprintf: Limit the length of inlined error messages vsprintf: Avoid confusion between invalid address and value vsprintf: Prevent crash when dereferencing invalid pointers vsprintf: Consolidate handling of unknown pointer specifiers vsprintf: Factor out %pO handler as kobject_string() vsprintf: Factor out %pV handler as va_format() vsprintf: Factor out %p[iI] handler as ip_addr_string() vsprintf: Do not check address of well-known strings vsprintf: Consistent %pK handling for kptr_restrict == 0 vsprintf: Shuffle restricted_pointer() printk: Tie printk_once / printk_deferred_once into .data.once for reset treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively lib/test_printf: Switch to bitmap_zalloc()

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-05-06T21:50:46Z

Pull timer updates from Ingo Molnar: "This cycle had the following changes: - Timer tracing improvements (Anna-Maria Gleixner) - Continued tasklet reduction work: remove the hrtimer_tasklet (Thomas Gleixner) - Fix CPU hotplug remove race in the tick-broadcast mask handling code (Thomas Gleixner) - Force upper bound for setting CLOCK_REALTIME, to fix ABI inconsistencies with handling values that are close to the maximum supported and the vagueness of when uptime related wraparound might occur. Make the consistent maximum the year 2232 across all relevant ABIs and APIs. (Thomas Gleixner) - various cleanups and smaller fixes" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick: Fix typos in comments tick/broadcast: Fix warning about undefined tick_broadcast_oneshot_offline() timekeeping: Force upper bound for setting CLOCK_REALTIME timer/trace: Improve timer tracing timer/trace: Replace deprecated vsprintf pointer extension %pf by %ps timer: Move trace point to get proper index tick/sched: Update tick_sched struct documentation tick: Remove outgoing CPU from broadcast masks timekeeping: Consistently use unsigned int for seqcount snapshot softirq: Remove tasklet_hrtimer xfrm: Replace hrtimer tasklet with softirq hrtimer mac80211_hwsim: Replace hrtimer tasklet with softirq hrtimer

timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze()

2019-04-18T12:34:53Z

tick_freeze() introduced by suspend-to-idle in commit 124cf9117c5f ("PM / sleep: Make it possible to quiesce timers during suspend-to-idle") uses timekeeping_suspend() instead of syscore_suspend() during suspend-to-idle. As a consequence generic sched_clock will keep going because sched_clock_suspend() and sched_clock_resume() are not invoked during suspend-to-idle which can result in a generic sched_clock wrap. On a ARM system with suspend-to-idle enabled, sched_clock is registered as "56 bits at 13MHz, resolution 76ns, wraps every 4398046511101ns", which means the real wrapping duration is 8796093022202ns. [ 134.551779] suspend-to-idle suspend (timekeeping_suspend()) [ 1204.912239] suspend-to-idle resume (timekeeping_resume()) ...... [ 1206.912239] suspend-to-idle suspend (timekeeping_suspend()) [ 5880.502807] suspend-to-idle resume (timekeeping_resume()) ...... [ 6000.403724] suspend-to-idle suspend (timekeeping_suspend()) [ 8035.753167] suspend-to-idle resume (timekeeping_resume()) ...... [ 8795.786684] (2)[321:charger_thread]...... [ 8795.788387] (2)[321:charger_thread]...... [ 0.057226] (0)[0:swapper/0]...... [ 0.061447] (2)[0:swapper/2]...... sched_clock was not stopped during suspend-to-idle, and sched_clock_poll hrtimer was not expired because timekeeping_suspend() was invoked during suspend-to-idle. It makes sched_clock wrap at kernel time 8796s. To prevent this, invoke sched_clock_suspend() and sched_clock_resume() in tick_freeze() together with timekeeping_suspend() and timekeeping_resume(). Fixes: 124cf9117c5f (PM / sleep: Make it possible to quiesce timers during suspend-to-idle) Signed-off-by: Chang-An Chen Signed-off-by: Thomas Gleixner Cc: Frederic Weisbecker Cc: Matthias Brugger Cc: John Stultz Cc: Kees Cook Cc: Corey Minyard Cc: Cc: Cc: Stanley Chu Cc: Cc: Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1553828349-8914-1-git-send-email-chang-an.chen@mediatek.com

treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively

2019-04-09T12:19:06Z

%pF and %pf are functionally equivalent to %pS and %ps conversion specifiers. The former are deprecated, therefore switch the current users to use the preferred variant. The changes have been produced by the following command: git grep -l '%p[fF]' | grep -v '^$tools\|Documentation$/' | \ while read i; do perl -i -pe 's/%pf/%ps/g; s/%pF/%pS/g;' $i; done And verifying the result. Link: http://lkml.kernel.org/r/20190325193229.23390-1-sakari.ailus@linux.intel.com Cc: Andy Shevchenko Cc: linux-arm-kernel@lists.infradead.org Cc: sparclinux@vger.kernel.org Cc: linux-um@lists.infradead.org Cc: xen-devel@lists.xenproject.org Cc: linux-acpi@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: drbd-dev@lists.linbit.com Cc: linux-block@vger.kernel.org Cc: linux-mmc@vger.kernel.org Cc: linux-nvdimm@lists.01.org Cc: linux-pci@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: linux-btrfs@vger.kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net Cc: linux-mm@kvack.org Cc: ceph-devel@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Sakari Ailus Acked-by: David Sterba (for btrfs) Acked-by: Mike Rapoport (for mm/memblock.c) Acked-by: Bjorn Helgaas (for drivers/pci) Acked-by: Rafael J. Wysocki Signed-off-by: Petr Mladek

timekeeping: Consistently use unsigned int for seqcount snapshot

2019-03-23T10:43:56Z

The timekeeping code uses a random mix of "unsigned long" and "unsigned int" for the seqcount snapshots (ratio 14:12). Since the seqlock.h API is entirely based on unsigned int, use that throughout. Signed-off-by: Rasmus Villemoes Signed-off-by: Thomas Gleixner Cc: Frederic Weisbecker Cc: John Stultz Cc: Stephen Boyd Link: https://lkml.kernel.org/r/20190318195557.20773-1-linux@rasmusvillemoes.dk

sched/clock: Remove license boilerplate

2018-11-23T10:51:22Z

The SPDX identifier defines the license of the file already. No need for the boilerplate. Signed-off-by: Thomas Gleixner Acked-by: Kees Cook Acked-by: Ingo Molnar Acked-by: John Stultz Acked-by: Corey Minyard Cc: Peter Zijlstra Cc: Kate Stewart Cc: Philippe Ombredanne Cc: Peter Anvin Cc: Russell King Cc: Richard Cochran Cc: "Paul E. McKenney" Cc: Nicolas Pitre Cc: David Riley Cc: Colin Cross Cc: Mark Brown Link: https://lkml.kernel.org/r/20181031182253.300140921@linutronix.de

time: Add SPDX license identifiers

2018-11-23T10:51:20Z

Update the time(r) core files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Philippe Ombredanne, Kate Stewart and myself. The data has been created with two independent license scanners and manual inspection. The following files do not contain any direct license information and have been omitted from the big initial SPDX changes: timeconst.bc: The .bc files were not touched time.c, timer.c, timekeeping.c: Licence was deduced from EXPORT_SYMBOL_GPL As those files do not contain direct license references they fall under the project license, i.e. GPL V2 only. Signed-off-by: Thomas Gleixner Acked-by: Kees Cook Acked-by: Ingo Molnar Acked-by: John Stultz Acked-by: Corey Minyard Cc: Peter Zijlstra Cc: Kate Stewart Cc: Philippe Ombredanne Cc: Russell King Cc: Richard Cochran Cc: Nicolas Pitre Cc: David Riley Cc: Colin Cross Cc: Mark Brown Cc: H. Peter Anvin Cc: Paul E. McKenney Link: https://lkml.kernel.org/r/20181031182252.879109557@linutronix.de