md: allow parallel resync of md-devices.
In some configurations, a raid6 resync can be limited by CPU speed
(Calculating P and Q and moving data) rather than by device speed. In
these cases there is nothing to be gained byt serialising resync of arrays
that share a device, and doing the resync in parallel can provide benefit.
So add a sysfs tunable to flag an array as being allowed to resync in
parallel with other arrays that use (a different part of) the same device.
Signed-off-by: Bernd Schubert <bs@q-leap.de>
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>
diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index 812ffa5..a6d7ab6 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -180,6 +180,9 @@
int sync_speed_min;
int sync_speed_max;
+ /* resync even though the same disks are shared among md-devices */
+ int parallel_resync;
+
int ok_start_degraded;
/* recovery/resync flags
* NEEDED: we might need to start a resync/recover