diff options
| author | Shengming Hu <hu.shengming@zte.com.cn> | 2026-01-19 21:59:05 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-02-08 00:13:34 -0800 |
| commit | cafe4074a7221dca2fa954dd1ab0cf99b6318e23 (patch) | |
| tree | c57b7ce20c3bcae50f6a10e9e8aaeb4fe6159cf4 | |
| parent | 9dc052234da736f7749f19ab6936342ec7dbe3ac (diff) | |
watchdog/softlockup: fix sample ring index wrap in need_counting_irqs()
cpustat_tail indexes cpustat_util[], which is a NUM_SAMPLE_PERIODS-sized
ring buffer. need_counting_irqs() currently wraps the index using
NUM_HARDIRQ_REPORT, which only happens to match NUM_SAMPLE_PERIODS.
Use NUM_SAMPLE_PERIODS for the wrap to keep the ring math correct even if
the NUM_HARDIRQ_REPORT or NUM_SAMPLE_PERIODS changes.
Link: https://lkml.kernel.org/r/tencent_7068189CB6D6689EB353F3D17BF5A5311A07@qq.com
Fixes: e9a9292e2368 ("watchdog/softlockup: Report the most frequent interrupts")
Signed-off-by: Shengming Hu <hu.shengming@zte.com.cn>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zhang Run <zhang.run@zte.com.cn>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | kernel/watchdog.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c index b4d5fbdb933a..7d675781bc91 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -550,7 +550,7 @@ static bool need_counting_irqs(void) u8 util; int tail = __this_cpu_read(cpustat_tail); - tail = (tail + NUM_HARDIRQ_REPORT - 1) % NUM_HARDIRQ_REPORT; + tail = (tail + NUM_SAMPLE_PERIODS - 1) % NUM_SAMPLE_PERIODS; util = __this_cpu_read(cpustat_util[tail][STATS_HARDIRQ]); return util > HARDIRQ_PERCENT_THRESH; } |