The patch titled Subject: doc: watchdog: modify the explanation related to watchdog thread has been added to the -mm tree. Its filename is doc-watchdog-modify-the-explanation-related-to-watchdog-thread.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/doc-watchdog-modify-the-explanation-related-to-watchdog-thread.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/doc-watchdog-modify-the-explanation-related-to-watchdog-thread.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Wang Qing <wangqing@xxxxxxxx> Subject: doc: watchdog: modify the explanation related to watchdog thread "watchdog/%u" threads has be replaced by cpu_stop_work. The current description is extremely misleading. Link: https://lkml.kernel.org/r/1619687073-24686-4-git-send-email-wangqing@xxxxxxxx Signed-off-by: Wang Qing <wangqing@xxxxxxxx> Reviewed-by: Petr Mladek <pmladek@xxxxxxxx> Cc: "Guilherme G. Piccoli" <gpiccoli@xxxxxxxxxxxxx> Cc: Joe Perches <joe@xxxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> Cc: Qais Yousef <qais.yousef@xxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Santosh Sivaraj <santosh@xxxxxxxxxx> Cc: Stephen Kitt <steve@xxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/admin-guide/lockup-watchdogs.rst | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/Documentation/admin-guide/lockup-watchdogs.rst~doc-watchdog-modify-the-explanation-related-to-watchdog-thread +++ a/Documentation/admin-guide/lockup-watchdogs.rst @@ -39,7 +39,7 @@ in principle, they should work in any ar subsystems are present. A periodic hrtimer runs to generate interrupts and kick the watchdog -task. An NMI perf event is generated every "watchdog_thresh" +job. An NMI perf event is generated every "watchdog_thresh" (compile-time initialized to 10 and configurable through sysctl of the same name) seconds to check for hardlockups. If any CPU in the system does not receive any hrtimer interrupt during that time the @@ -47,7 +47,7 @@ does not receive any hrtimer interrupt d generate a kernel warning or call panic, depending on the configuration. -The watchdog task is a high priority kernel thread that updates a +The watchdog job runs in a stop scheduling thread that updates a timestamp every time it is scheduled. If that timestamp is not updated for 2*watchdog_thresh seconds (the softlockup threshold) the 'softlockup detector' (coded inside the hrtimer callback function) _ Patches currently in -mm which might be from wangqing@xxxxxxxx are kernel-watchdog-modify-the-explanation-related-to-watchdog-thread.patch doc-watchdog-modify-the-explanation-related-to-watchdog-thread.patch doc-watchdog-modify-the-doc-related-to-watchdog-%u.patch