diff options
Diffstat (limited to 'Documentation/ABI/testing')
-rw-r--r-- | Documentation/ABI/testing/sysfs-block | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block index d2f90334bb93..4873c759d535 100644 --- a/Documentation/ABI/testing/sysfs-block +++ b/Documentation/ABI/testing/sysfs-block | |||
@@ -128,3 +128,17 @@ Description: | |||
128 | preferred request size for workloads where sustained | 128 | preferred request size for workloads where sustained |
129 | throughput is desired. If no optimal I/O size is | 129 | throughput is desired. If no optimal I/O size is |
130 | reported this file contains 0. | 130 | reported this file contains 0. |
131 | |||
132 | What: /sys/block/<disk>/queue/nomerges | ||
133 | Date: January 2010 | ||
134 | Contact: | ||
135 | Description: | ||
136 | Standard I/O elevator operations include attempts to | ||
137 | merge contiguous I/Os. For known random I/O loads these | ||
138 | attempts will always fail and result in extra cycles | ||
139 | being spent in the kernel. This allows one to turn off | ||
140 | this behavior on one of two ways: When set to 1, complex | ||
141 | merge checks are disabled, but the simple one-shot merges | ||
142 | with the previous I/O request are enabled. When set to 2, | ||
143 | all merge tries are disabled. The default value is 0 - | ||
144 | which enables all types of merge tries. | ||