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| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2010-03-05 15:46:18 -0500 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2010-03-05 15:46:18 -0500 |
| commit | 3fa04ecd72780da31ba8b329e148179bc24a9c7d (patch) | |
| tree | f5d462fd4aee086952d18f159f737c450ab46b3b /Documentation/ABI/testing/sysfs-block | |
| parent | 180b62a3d837613fcac3ce89576526423926c3c3 (diff) | |
| parent | 1cda707d52e51a6cafac0aef12d2bd7052d572e6 (diff) | |
Merge branch 'writeback-for-2.6.34' into nfs-for-2.6.34
Diffstat (limited to 'Documentation/ABI/testing/sysfs-block')
| -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 d2f90334bb9..4873c759d53 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. |