From: Hungyu Lin <dennylin0707@gmail.com>
To: anna-maria@linutronix.de, frederic@kernel.org
Cc: tglx@kernel.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org, Hungyu Lin <dennylin0707@gmail.com>
Subject: [PATCH] timers/itimer: Keep a nonzero value at CPU timer expiry
Date: Tue, 20 Oct 2026 22:39:57 +0000 [thread overview]
Message-ID: <20261020223957.87842-1-dennylin0707@gmail.com> (raw)
get_cpu_itimer() returns a zero remaining time when the sampled CPU time
is exactly equal to the nonzero expiry. This makes an armed ITIMER_VIRTUAL
or ITIMER_PROF timer appear disarmed.
The cputime cleanup replaced cputime_le(), which implements <=, with <.
Restore the inclusive comparison so the equality case returns TICK_NSEC,
like the overdue case and set_process_cpu_timer().
Fixes: 648616343cdb ("[S390] cputime: add sparse checking and cleanup")
Cc: stable@vger.kernel.org
Signed-off-by: Hungyu Lin <dennylin0707@gmail.com>
---
kernel/time/itimer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/time/itimer.c b/kernel/time/itimer.c
index 03a32dffc56c..f7de39769095 100644
--- a/kernel/time/itimer.c
+++ b/kernel/time/itimer.c
@@ -60,7 +60,7 @@ static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
thread_group_sample_cputime(tsk, samples);
t = samples[clock_id];
- if (val < t)
+ if (val <= t)
/* about to fire */
val = TICK_NSEC;
else
--
2.43.0
reply other threads:[~2026-10-20 22:48 UTC|newest]
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