Call WITNESS_WARN() in callout_drain() to check whether any locks are

being held before sleeping.

This has bitten me (in ath(4)) once before and I'd like to see this
not bite anyone else.

Differential Revision:	D1638
Reviewed by:	jhb, hselasky
MFC after:	1 week

This commit is contained in:

Adrian Chadd

2015-01-26 04:04:57 +00:00

parent e505aef3ed

commit 9500dd9f0b

1 changed files with 4 additions and 0 deletions

									
										sys/kern/kern_timeout.c
									
		+4
		
												View File
												
				@@ -1096,6 +1096,10 @@ _callout_stop_safe(struct callout *c, int safe)

					struct lock_class *class;

					int direct, sq_locked, use_lock;

					if (safe)

						WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, c->c_lock,

						    "calling %s", __func__);

					/*

					 * Some old subsystems don't hold Giant while running a callout_stop(),

					 * so just discard this check for the moment.