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| author | Mike Snitzer <snitzer@redhat.com> | 2016-01-31 17:22:27 -0500 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2016-02-22 11:06:22 -0500 |
| commit | 16f122661dbb3dfefc60788b528b54ad702005aa (patch) | |
| tree | 500f1868d0342e7d61eeb86337d0120532d37d78 /drivers/md/dm-mpath.c | |
| parent | f083b09b7819c785db4f82a81f68da3bccfb04bf (diff) | |
| download | linux-16f122661dbb3dfefc60788b528b54ad702005aa.tar.gz linux-16f122661dbb3dfefc60788b528b54ad702005aa.tar.bz2 linux-16f122661dbb3dfefc60788b528b54ad702005aa.zip | |
dm: optimize dm_mq_queue_rq()
DM multipath is the only dm-mq target. But that aside, request-based DM
only supports tables with a single target that is immutable. Leverage
this fact in dm_mq_queue_rq() by using the 'immutable_target' stored in
the mapped_device when the table was made active. This saves the need
to even take the read-side of the SRCU via dm_{get,put}_live_table.
If the active DM table does not have an immutable target (e.g. "error"
target was swapped in) then fallback to the slow-path where the target
is looked up from the live table.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-mpath.c')
| -rw-r--r-- | drivers/md/dm-mpath.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index cfa29f574c2a..3ddaa11584ef 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -1684,7 +1684,8 @@ out: *---------------------------------------------------------------*/ static struct target_type multipath_target = { .name = "multipath", - .version = {1, 10, 0}, + .version = {1, 11, 0}, + .features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE, .module = THIS_MODULE, .ctr = multipath_ctr, .dtr = multipath_dtr, |