1 files changed, 15 insertions, 1 deletions

diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block
index 5f3bedaf8e35..4873c759d535 100644
--- a/Documentation/ABI/testing/sysfs-block
+++ b/Documentation/ABI/testing/sysfs-block
@@ -4,7 +4,7 @@ Contact:	Jerome Marchand <jmarchan@redhat.com>
 Description:
                 The /sys/block/<disk>/stat files displays the I/O
                 statistics of disk <disk>. They contain 11 fields:
-                 1 - reads completed succesfully
+                 1 - reads completed successfully
                  2 - reads merged
                  3 - sectors read
                  4 - time spent reading (ms)
@@ -128,3 +128,17 @@ Description:
                 preferred request size for workloads where sustained
                 throughput is desired.  If no optimal I/O size is
                 reported this file contains 0.
+
+What:           /sys/block/<disk>/queue/nomerges
+Date:           January 2010
+Contact:
+Description:
+                Standard I/O elevator operations include attempts to
+                merge contiguous I/Os. For known random I/O loads these
+                attempts will always fail and result in extra cycles
+                being spent in the kernel. This allows one to turn off
+                this behavior on one of two ways: When set to 1, complex
+                merge checks are disabled, but the simple one-shot merges
+                with the previous I/O request are enabled. When set to 2,
+                all merge tries are disabled. The default value is 0 -
+                which enables all types of merge tries.