when I test bcache on linux 3.10 kernel, use writeback cache mode, the capability of the ssd cache is 240G. fio -filename=/dev/bcache0 -direct=1 -iodepth 1 -thread -rw=randwrite -ioengine=psync -bs=4k -size=80G -numjobs=8 -runtime=30000 -group_reporting -name=mytes the performance can reach to 1.2w. after two hours running, the performance drop to 500. what is the reason? when stop fio, iostat show results: Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn sde 2697.00 0.00 10.54 0 10 sdc 0.00 0.00 0.00 0 0 sdd 0.00 0.00 0.00 0 0 sda 0.00 0.00 0.00 0 0 sdb 2715.00 10.55 0.06 10 0 dm-0 0.00 0.00 0.00 0 0 dm-1 0.00 0.00 0.00 0 0 dm-2 0.00 0.00 0.00 0 0 dm-3 0.00 0.00 0.00 0 0 dm-4 0.00 0.00 0.00 0 0 bcache0 0.00 0.00 0.00 0 0 -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html