From: <gregkh@linuxfoundation.org>
To: tglx@kernel.org,dnaim@cachyos.org,i.r.e.c.c.a.k.u.n+kernel.org@gmail.com
Cc: <stable@vger.kernel.org>
Subject: FAILED: patch "[PATCH] clockevents: Add missing resets of the next_event_forced flag" failed to apply to 7.0-stable tree
Date: Tue, 12 May 2026 15:50:58 +0200 [thread overview]
Message-ID: <2026051258-schedule-parcel-c95c@gregkh> (raw)
The patch below does not apply to the 7.0-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-7.0.y
git checkout FETCH_HEAD
git cherry-pick -x 4096fd0e8eaea13ebe5206700b33f49635ae18e5
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026051258-schedule-parcel-c95c@gregkh' --subject-prefix 'PATCH 7.0.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 4096fd0e8eaea13ebe5206700b33f49635ae18e5 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@kernel.org>
Date: Tue, 14 Apr 2026 22:55:01 +0200
Subject: [PATCH] clockevents: Add missing resets of the next_event_forced flag
The prevention mechanism against timer interrupt starvation missed to reset
the next_event_forced flag in a couple of places:
- When the clock event state changes. That can cause the flag to be
stale over a shutdown/startup sequence
- When a non-forced event is armed, which then prevents rearming before
that event. If that event is far out in the future this will cause
missed timer interrupts.
- In the suspend wakeup handler.
That led to stalls which have been reported by several people.
Add the missing resets, which fixes the problems for the reporters.
Fixes: d6e152d905bd ("clockevents: Prevent timer interrupt starvation")
Reported-by: Hanabishi <i.r.e.c.c.a.k.u.n+kernel.org@gmail.com>
Reported-by: Eric Naim <dnaim@cachyos.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Hanabishi <i.r.e.c.c.a.k.u.n+kernel.org@gmail.com>
Tested-by: Eric Naim <dnaim@cachyos.org>
Cc: stable@vger.kernel.org
Closes: https://lore.kernel.org/68d1e9ac-2780-4be3-8ee3-0788062dd3a4@gmail.com
Link: https://patch.msgid.link/87340xfeje.ffs@tglx
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index b4d730604972..5e22697b098d 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -94,6 +94,9 @@ static int __clockevents_switch_state(struct clock_event_device *dev,
if (dev->features & CLOCK_EVT_FEAT_DUMMY)
return 0;
+ /* On state transitions clear the forced flag unconditionally */
+ dev->next_event_forced = 0;
+
/* Transition with new state-specific callbacks */
switch (state) {
case CLOCK_EVT_STATE_DETACHED:
@@ -366,8 +369,10 @@ int clockevents_program_event(struct clock_event_device *dev, ktime_t expires, b
if (delta > (int64_t)dev->min_delta_ns) {
delta = min(delta, (int64_t) dev->max_delta_ns);
cycles = ((u64)delta * dev->mult) >> dev->shift;
- if (!dev->set_next_event((unsigned long) cycles, dev))
+ if (!dev->set_next_event((unsigned long) cycles, dev)) {
+ dev->next_event_forced = 0;
return 0;
+ }
}
if (dev->next_event_forced)
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 7e57fa31ee26..115e0bf01276 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -108,6 +108,7 @@ static struct clock_event_device *tick_get_oneshot_wakeup_device(int cpu)
static void tick_oneshot_wakeup_handler(struct clock_event_device *wd)
{
+ wd->next_event_forced = 0;
/*
* If we woke up early and the tick was reprogrammed in the
* meantime then this may be spurious but harmless.
next reply other threads:[~2026-05-12 13:50 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-12 13:50 gregkh [this message]
2026-05-14 10:50 ` FAILED: patch "[PATCH] clockevents: Add missing resets of the next_event_forced flag" failed to apply to 7.0-stable tree Thomas Gleixner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2026051258-schedule-parcel-c95c@gregkh \
--to=gregkh@linuxfoundation.org \
--cc=dnaim@cachyos.org \
--cc=i.r.e.c.c.a.k.u.n+kernel.org@gmail.com \
--cc=stable@vger.kernel.org \
--cc=tglx@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox