linux.git/kernel/time/hrtimer.c, branch v6.18.21

hrtimer: Fix trace oddity

2026-02-26T22:59:03+00:00

[ Upstream commit 5d6446f409da00e5a389125ddb5ce09f5bc404c9 ]

It turns out that __run_hrtimer() will trace like:

          -0     [032] d.h2. 20705.474563: hrtimer_cancel:       hrtimer=0xff2db8f77f8226e8
          -0     [032] d.h1. 20705.474563: hrtimer_expire_entry: hrtimer=0xff2db8f77f8226e8 now=20699452001850 function=tick_nohz_handler/0x0

Which is a bit nonsensical, the timer doesn't get canceled on
expiration. The cause is the use of the incorrect debug helper.

Fixes: c6a2a1770245 ("hrtimer: Add tracepoint for hrtimers")
Reported-by: Peter Zijlstra (Intel) 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://patch.msgid.link/20260121143208.219595606@infradead.org
Signed-off-by: Sasha Levin

hrtimer: Fix softirq base check in update_needs_ipi()

2026-01-23T10:21:28+00:00

commit 05dc4a9fc8b36d4c99d76bbc02aa9ec0132de4c2 upstream.

The 'clockid' field is not the correct way to check for a softirq base.

Fix the check to correctly compare the base type instead of the clockid.

Fixes: 1e7f7fbcd40c ("hrtimer: Avoid more SMP function calls in clock_was_set()")
Signed-off-by: Thomas Weißschuh 
Signed-off-by: Thomas Gleixner 
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260107-hrtimer-clock-base-check-v1-1-afb5dbce94a1@linutronix.de
Signed-off-by: Greg Kroah-Hartman

Merge tag 'timers-core-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-09-30T23:09:27+00:00

Pull timer core updates from Thomas Gleixner:

 - Address the inconsistent shutdown sequence of per CPU clockevents on
   CPU hotplug, which only removed it from the core but failed to invoke
   the actual device driver shutdown callback. This kept the timer
   active, which prevented power savings and caused pointless noise in
   virtualization.

 - Encapsulate the open coded access to the hrtimer clock base, which is
   a private implementation detail, so that the implementation can be
   changed without breaking a lot of usage sites.

 - Enhance the debug output of the clocksource watchdog to provide
   better information for analysis.

 - The usual set of cleanups and enhancements all over the place

* tag 'timers-core-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Fix spelling mistakes in comments
  clocksource: Print durations for sync check unconditionally
  LoongArch: Remove clockevents shutdown call on offlining
  tick: Do not set device to detached state in tick_shutdown()
  hrtimer: Reorder branches in hrtimer_clockid_to_base()
  hrtimer: Remove hrtimer_clock_base:: Get_time
  hrtimer: Use hrtimer_cb_get_time() helper
  media: pwm-ir-tx: Avoid direct access to hrtimer clockbase
  ALSA: hrtimer: Avoid direct access to hrtimer clockbase
  lib: test_objpool: Avoid direct access to hrtimer clockbase
  sched/core: Avoid direct access to hrtimer clockbase
  timers/itimer: Avoid direct access to hrtimer clockbase
  posix-timers: Avoid direct access to hrtimer clockbase
  jiffies: Remove obsolete SHIFTED_HZ comment

time: Fix spelling mistakes in comments

2025-09-21T08:02:02+00:00

Correct several typos found in comments across various files in the
kernel/time directory.

No functional changes are introduced by these corrections.

Signed-off-by: Haofeng Li 
Signed-off-by: Thomas Gleixner

hrtimers: Unconditionally update target CPU base after offline timer migration

2025-09-09T12:05:16+00:00

When testing softirq based hrtimers on an ARM32 board, with high resolution
mode and NOHZ inactive, softirq based hrtimers fail to expire after being
moved away from an offline CPU:

CPU0				CPU1
				hrtimer_start(..., HRTIMER_MODE_SOFT);
cpu_down(CPU1)			...
				hrtimers_cpu_dying()
				  // Migrate timers to CPU0
				  smp_call_function_single(CPU0, returgger_next_event);
  retrigger_next_event()
    if (!highres && !nohz)
        return;

As retrigger_next_event() is a NOOP when both high resolution timers and
NOHZ are inactive CPU0's hrtimer_cpu_base::softirq_expires_next is not
updated and the migrated softirq timers never expire unless there is a
softirq based hrtimer queued on CPU0 later.

Fix this by removing the hrtimer_hres_active() and tick_nohz_active() check
in retrigger_next_event(), which enforces a full update of the CPU base.
As this is not a fast path the extra cost does not matter.

[ tglx: Massaged change log ]

Fixes: 5c0930ccaad5 ("hrtimers: Push pending hrtimers away from outgoing CPU earlier")
Co-developed-by: Frederic Weisbecker 
Signed-off-by: Frederic Weisbecker 
Signed-off-by: Xiongfeng Wang 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/20250805081025.54235-1-wangxiongfeng2@huawei.com

hrtimer: Reorder branches in hrtimer_clockid_to_base()

2025-09-09T10:27:18+00:00

Align the ordering to the one used for hrtimer_bases.

Signed-off-by: Thomas Weißschuh 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/20250821-hrtimer-cleanup-get_time-v2-9-3ae822e5bfbd@linutronix.de

hrtimer: Remove hrtimer_clock_base:: Get_time

2025-09-09T10:27:18+00:00

The get_time() callbacks always need to match the bases clockid.
Instead of maintaining that association twice in hrtimer_bases,
use a helper.

Signed-off-by: Thomas Weißschuh 
Signed-off-by: Thomas Gleixner 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lore.kernel.org/all/20250821-hrtimer-cleanup-get_time-v2-8-3ae822e5bfbd@linutronix.de

hrtimer: Add missing ACCESS_PRIVATE() for hrtimer::function

2025-04-09T19:00:42+00:00

The "function" field of struct hrtimer has been changed to private, but
two instances have not been converted to use ACCESS_PRIVATE().

Convert them to use ACCESS_PRIVATE().

Fixes: 04257da0c99c ("hrtimers: Make callback function pointer private")
Reported-by: kernel test robot 
Signed-off-by: Nam Cao 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/20250408103854.1851093-1-namcao@linutronix.de
Closes: https://lore.kernel.org/oe-kbuild-all/202504071931.vOVl13tt-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202504072155.5UAZjYGU-lkp@intel.com/

tracing/timers: Rename the hrtimer_init event to hrtimer_setup

2025-04-05T08:30:17+00:00

The function hrtimer_init() doesn't exist anymore. It was replaced by
hrtimer_setup().

Thus, rename the hrtimer_init trace event to hrtimer_setup to keep it
consistent.

Signed-off-by: Nam Cao 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar 
Link: https://lore.kernel.org/all/cba84c3d853c5258aa3a262363a6eac08e2c7afc.1738746927.git.namcao@linutronix.de

hrtimers: Rename debug_init_on_stack() to debug_setup_on_stack()

2025-04-05T08:30:17+00:00

All the hrtimer_init*() functions have been renamed to hrtimer_setup*().
Rename debug_init_on_stack() to debug_setup_on_stack() as well, to keep the
names consistent.

Signed-off-by: Nam Cao 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar 
Link: https://lore.kernel.org/all/073cf6162779a2f5b12624677d4c49ee7eccc1ed.1738746927.git.namcao@linutronix.de