Lukas Czerner <lczerner@xxxxxxxxxx> 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@xxxxxxxxxx> > Reported-by: Dave Chinner <dchinner@xxxxxxxxxx> 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@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
