Linux kernel stable tree (mirror) https://git.radix-linux.su/kernel/linux.git/atom?h=v6.18.21 2025-05-21T17:48:22+00:00 2025-05-21T17:48:22+00:00 Max Kellermann max.kellermann@ionos.com 2025-05-04T18:08:30+00:00 urn:sha1:aaf05e96e93cb9c8fc8d35fc4525715530397655 Patch series "sysfs: add counters for lockups and stalls", v2. Commits 9db89b411170 ("exit: Expose "oops_count" to sysfs") and 8b05aa263361 ("panic: Expose "warn_count" to sysfs") added counters for oopses and warnings to sysfs, and these two patches do the same for hard/soft lockups and RCU stalls. All of these counters are useful for monitoring tools to detect whether the machine is healthy. If the kernel has experienced a lockup or a stall, it's probably due to a kernel bug, and I'd like to detect that quickly and easily. There is currently no way to detect that, other than parsing dmesg. Or observing indirect effects: such as certain tasks not responding, but then I need to observe all tasks, and it may take a while until these effects become visible/measurable. I'd rather be able to detect the primary cause more quickly, possibly before everything falls apart. This patch (of 2): There is /proc/sys/kernel/hung_task_detect_count, /sys/kernel/warn_count and /sys/kernel/oops_count but there is no userspace-accessible counter for hard/soft lockups. Having this is useful for monitoring tools. Link: https://lkml.kernel.org/r/20250504180831.4190860-1-max.kellermann@ionos.com Link: https://lkml.kernel.org/r/20250504180831.4190860-2-max.kellermann@ionos.com Signed-off-by: Max Kellermann <max.kellermann@ionos.com> Cc: Cc: Core Minyard <cminyard@mvista.com> Cc: Doug Anderson <dianders@chromium.org> Cc: Joel Granados <joel.granados@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Kees Cook <kees@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>