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: 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. |