On Wed, Aug 31 2005, Brian King wrote: > Jens Axboe wrote: > > On Tue, Aug 30 2005, [EMAIL PROTECTED] wrote: > > > >>I ran across a memory leak related to the cfq scheduler. The cfq > >>init function increments the refcnt of the associated request_queue. > >>This refcount gets decremented in cfq's exit function. Since > >>blk_cleanup_queue > >>only calls the elevator exit function when its refcnt goes to zero, the > >>request_q never gets cleaned up. It didn't look like other io schedulers > >>were > >>incrementing this refcnt, so I removed the refcnt increment and it fixed the > >>memory leak for me. > >> > >>To reproduce the problem, simply use cfq and use the scsi_host scan sysfs > >>attribute to scan "- - -" repeatedly on a scsi host and watch the memory > >>vanish. > > > > > > Yeah, that actually looks like a dangling reference. I assume you tested > > this properly? > > Yes. I applied the patch, booted my system (which was crashing on > bootup before due to out of memory errors due to the leak) ran the > scan a few times and verified /proc/meminfo didn't continually > decrease like without it, and rebooted again. If there is anything > else you would like me to do, I would be happy to do so.
I think you need to remove the blk_put_queue() in cfq_put_cfqd() as well, otherwise I don't see how this can work without looking at freed memory. I'll audit the other paths as well. -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
