Commit-ID: 88f1c87de11a86d839f4ce5313e552d96709b990 Gitweb: https://git.kernel.org/tip/88f1c87de11a86d839f4ce5313e552d96709b990 Author: Tejun Heo <t...@kernel.org> AuthorDate: Mon, 22 Jan 2018 14:00:55 -0800 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Wed, 24 Jan 2018 10:00:09 +0100
locking/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 <t...@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: kernel-t...@fb.com Link: http://lkml.kernel.org/r/20180122220055.gb1771...@devbig577.frc2.facebook.com Signed-off-by: Ingo Molnar <mi...@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 @@ retry: if (!unlock) if (read_trylock(&tasklist_lock)) unlock = 1; + touch_nmi_watchdog(); } while_each_thread(g, p); pr_warn("\n");
