While playing around with zcache+zram (see separate thread), I was watching stats with "watch -d". It appears from the code that /sys/block/num_writes only increases, never decreases. In my test, num_writes got up to 1863. /sys/block/disksize is 104857600. I have two swap disks, one zram (pri=60), one real (pri=-1), and as a I watched /proc/swaps, the "Used" field grew rapidly and reached the Size (102396k) of the zram swap, and then the second swap disk (a physical disk partition) started being used. Then for awhile, the Used field for both swap devices was changing (up and down). Can you explain how this could happen if num_writes never exceeded 1863? This may be harmless in the case where the only swap on the system is zram; or may indicate a bug somewhere? It looks like num_writes is counting bio's not pages... which would imply the bio's are potentially quite large (and I'll guess they are of size SWAPFILE_CLUSTER which is defined to be 256). Do large clusters make sense with zram? Late on a Friday so sorry if I am incomprehensible... P.S. The corresponding stat for zcache indicates that it failed 8852 stores, so I would have expected zram to deal with no more than 8852 compressions. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href