Merge with http://kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 867f06ae33d9..713dc9c2c730 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -552,7 +552,11 @@ static int read_balance(conf_t *conf, r10bio_t *r10_bio)
                     !test_bit(In_sync, &rdev->flags))
                         continue;
 
-                if (!atomic_read(&rdev->nr_pending)) {
+                /* This optimisation is debatable, and completely destroys
+                 * sequential read speed for 'far copies' arrays.  So only
+                 * keep it for 'near' arrays, and review those later.
+                 */
+                if (conf->near_copies > 1 && !atomic_read(&rdev->nr_pending)) {
                         disk = ndisk;
                         slot = nslot;
                         break;