diff options
| author | Li RongQing <lirongqing@baidu.com> | 2025-12-16 02:45:21 -0500 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-01-20 19:44:20 -0800 |
| commit | e700f5d1560798aacf0e56fdcc70ee2c20bf56ec (patch) | |
| tree | dd3150ba18c28fb686f4520096f51f7f9b41ad25 /Documentation | |
| parent | b5bfcc1ffe512c7879cb90befdeabaa43d9f07ca (diff) | |
watchdog: softlockup: panic when lockup duration exceeds N thresholds
The softlockup_panic sysctl is currently a binary option: panic
immediately or never panic on soft lockups.
Panicking on any soft lockup, regardless of duration, can be overly
aggressive for brief stalls that may be caused by legitimate operations.
Conversely, never panicking may allow severe system hangs to persist
undetected.
Extend softlockup_panic to accept an integer threshold, allowing the
kernel to panic only when the normalized lockup duration exceeds N
watchdog threshold periods. This provides finer-grained control to
distinguish between transient delays and persistent system failures.
The accepted values are:
- 0: Don't panic (unchanged)
- 1: Panic when duration >= 1 * threshold (20s default, original behavior)
- N > 1: Panic when duration >= N * threshold (e.g., 2 = 40s, 3 = 60s.)
The original behavior is preserved for values 0 and 1, maintaining full
backward compatibility while allowing systems to tolerate brief lockups
while still catching severe, persistent hangs.
[lirongqing@baidu.com: v2]
Link: https://lkml.kernel.org/r/20251218074300.4080-1-lirongqing@baidu.com
Link: https://lkml.kernel.org/r/20251216074521.2796-1-lirongqing@baidu.com
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Song Liu <song@kernel.org>
Cc: Stanislav Fomichev <sdf@fomichev.me>
Cc: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 1058f2a6d6a8..73d846211144 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6969,12 +6969,12 @@ Kernel parameters softlockup_panic= [KNL] Should the soft-lockup detector generate panics. - Format: 0 | 1 + Format: <int> - A value of 1 instructs the soft-lockup detector - to panic the machine when a soft-lockup occurs. It is - also controlled by the kernel.softlockup_panic sysctl - and CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC, which is the + A value of non-zero instructs the soft-lockup detector + to panic the machine when a soft-lockup duration exceeds + N thresholds. It is also controlled by the kernel.softlockup_panic + sysctl and CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC, which is the respective build-time switch to that functionality. softlockup_all_cpu_backtrace= |