Messages in this thread Patch in this message | | | Date | Mon, 22 Jan 2018 14:00:55 -0800 | From | Tejun Heo <> | Subject | [PATCH] lockdep: Avoid triggering hardlockup from debug_show_all_locks() |
| |
debug_show_all_locks() iterates all tasks and print held locks whole holding tasklist_lock. This can take a while on a slow console device and may end up triggering NMI hardlockup detector if someone else ends up waiting for tasklist_lock.
Touch the NMI watchdog while printing the held locks to avoid spuriously triggering the hardlockup detector.
Signed-off-by: Tejun Heo <tj@kernel.org> --- kernel/locking/lockdep.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 5fa1324..5216590 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -49,6 +49,7 @@ #include <linux/gfp.h> #include <linux/random.h> #include <linux/jhash.h> +#include <linux/nmi.h> #include <asm/sections.h> @@ -4490,6 +4491,7 @@ void debug_show_all_locks(void) if (!unlock) if (read_trylock(&tasklist_lock)) unlock = 1; + touch_nmi_watchdog(); } while_each_thread(g, p); pr_warn("\n");
| |