NeilBrown 435b71be20 md: improve the is_mddev_idle test ... During a 'resync' or similar activity, md checks if the devices in the array are otherwise active and winds back resync activity when they are. This test in done in is_mddev_idle, and it is somewhat fragile - it sometimes thinks there is non-sync io when there isn't. The test compares the total sectors of io (disk_stat_read) with the sectors of resync io (disk->sync_io). This has problems because total sectors gets updated when a request completes, while resync io gets updated when the request is submitted. The time difference can cause large differenced between the two which do not actually imply non-resync activity. The test currently allows for some fuzz (+/- 4096) but there are some cases when it is not enough. The test currently looks for any (non-fuzz) difference, either positive or negative. This clearly is not needed. Any non-sync activity will cause the total sectors to grow faster than the sync_io count (never slower) so we only need to look for a positive differences. If we do this then the amount of in-flight sync io will never cause the appearance of non-sync IO. Once enough non-sync IO to worry about starts happening, resync will be slowed down and the measurements will thus be more precise (as there is less in-flight) and control of resync will still be suitably responsive. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2007-05-11 08:29:37 -07:00
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raid6test
.gitignore
bitmap.c
dm-bio-list.h
dm-bio-record.h
dm-crypt.c
dm-delay.c
dm-emc.c
dm-exception-store.c
dm-hw-handler.c
dm-hw-handler.h
dm-io.c
dm-io.h
dm-ioctl.c
dm-linear.c
dm-log.c
dm-log.h
dm-mpath.c
dm-mpath.h
dm-path-selector.c
dm-path-selector.h
dm-raid1.c
dm-round-robin.c
dm-snap.c
dm-snap.h
dm-stripe.c
dm-table.c
dm-target.c
dm-zero.c
dm.c
dm.h
faulty.c
Kconfig
kcopyd.c
kcopyd.h
linear.c
Makefile
md.c
mktables.c
multipath.c
raid1.c
raid5.c
raid6.h
raid6algos.c
raid6altivec.uc
raid6int.uc
raid6mmx.c
raid6recov.c
raid6sse1.c
raid6sse2.c
raid6x86.h
raid10.c
raid0.c
unroll.pl
xor.c