Messages in this thread | | | From | Jeff Moyer <> | Subject | Re: [PATCH 2/2 v6] loop: Limit the number of requests in the bio list | Date | Fri, 30 Nov 2012 08:57:23 -0500 |
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Lukas Czerner <lczerner@redhat.com> writes:
> Currently there is not limitation of number of requests in the loop bio > list. This can lead into some nasty situations when the caller spawns > tons of bio requests taking huge amount of memory. This is even more > obvious with discard where blkdev_issue_discard() will submit all bios > for the range and wait for them to finish afterwards. On really big loop > devices and slow backing file system this can lead to OOM situation as > reported by Dave Chinner. > > With this patch we will wait in loop_make_request() if the number of > bios in the loop bio list would exceed 'nr_congestion_on'. > We'll wake up the process as we process the bios form the list. Some > threshold hysteresis is in place to avoid high frequency oscillation. > > Signed-off-by: Lukas Czerner <lczerner@redhat.com> > Reported-by: Dave Chinner <dchinner@redhat.com>
Lukas, please carry forward acked-by tags when there is no change so I don't have to keep acking.
Thanks, Jeff
Acked-by: Jeff Moyer <jmoyer@redhat.com>
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