svn commit: r184217 - head/sys/kern

[John Baldwin]

On Thursday 23 October 2008 09:09:25 pm David Xu wrote:
> Author: davidxu
> Date: Fri Oct 24 01:09:24 2008
> New Revision: 184217
> URL: http://svn.freebsd.org/changeset/base/184217
> 
> Log:
>   Don't rearm callout if the process is exiting, it may leak a callout
>   because callout_drain() only waits for running callout, but not disable
>   it if it is rearmed.

Actually, it does prevent rearming from within the callout routine itself 
while waiting:

int
callout_reset_on(struct callout *c, int to_ticks, void (*ftn)(void *),
    void *arg, int cpu)
{
	...
	if (cc->cc_curr == c) {
		...
		if (cc->cc_waiting) {
			/*
			 * Someone has called callout_drain to kill this
			 * callout.  Don't reschedule.
			 */
			CTR4(KTR_CALLOUT, "%s %p func %p arg %p",
			    cancelled ? "cancelled" : "failed to cancel",
			    c, c->c_func, c->c_arg);
			CC_UNLOCK(cc);
			return (cancelled);
		}
	}
	...
}

Lots of callouts using callout_init_mtx() (e.g. all the callouts in the NIC 
drivers) depend on this feature.  Please revert this.

-- 
John Baldwin