dm thin: commit outstanding data every second
commit905e51b39a5558706a6ed883fe104de3d417050b
authorJoe Thornber <ejt@redhat.com>
Wed, 28 Mar 2012 17:41:27 +0000 (28 18:41 +0100)
committerAlasdair G Kergon <agk@redhat.com>
Wed, 28 Mar 2012 17:41:27 +0000 (28 18:41 +0100)
treed8e1d9fcdba66942333f099618e6acc5be238538
parent31998ef19385c944600d9a981b96252f98204bee
dm thin: commit outstanding data every second

Commit unwritten data every second to prevent too much building up.

Released blocks don't become available until after the next commit
(for crash resilience).  Prior to this patch commits were only
triggered by a message to the target or a REQ_{FLUSH,FUA} bio.  This
allowed far too big a position to build up.

The interval is hard-coded to 1 second.  This is a sensible setting.
I'm not making this user configurable, since there isn't much to be
gained by tweaking this - and a lot lost by setting it far too high.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
drivers/md/dm-thin.c