path: root/Documentation
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authorLinus Torvalds <torvalds@g5.osdl.org>2006-04-20 08:17:04 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-04-20 08:17:04 -0700
commit402a26f0c040077ed6f941eefac5a6971f0d5f40 (patch)
treef74e5d732404e9716b3c753007bac0f5d1e92869 /Documentation
parentMerge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6 (diff)
parent[PATCH] block/elevator.c: remove unused exports (diff)
Merge branch 'for-linus' of git://brick.kernel.dk/data/git/linux-2.6-block
* 'for-linus' of git://brick.kernel.dk/data/git/linux-2.6-block: [PATCH] block/elevator.c: remove unused exports [PATCH] splice: fix smaller sized splice reads [PATCH] Don't inherit ->splice_pipe across forks [patch] cleanup: use blk_queue_stopped [PATCH] Document online io scheduler switching
Diffstat (limited to 'Documentation')
1 files changed, 22 insertions, 0 deletions
diff --git a/Documentation/block/switching-sched.txt b/Documentation/block/switching-sched.txt
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+++ b/Documentation/block/switching-sched.txt
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+As of the Linux 2.6.10 kernel, it is now possible to change the
+IO scheduler for a given block device on the fly (thus making it possible,
+for instance, to set the CFQ scheduler for the system default, but
+set a specific device to use the anticipatory or noop schedulers - which
+can improve that device's throughput).
+To set a specific scheduler, simply do this:
+echo SCHEDNAME > /sys/block/DEV/queue/scheduler
+where SCHEDNAME is the name of a defined IO scheduler, and DEV is the
+device name (hda, hdb, sga, or whatever you happen to have).
+The list of defined schedulers can be found by simply doing
+a "cat /sys/block/DEV/queue/scheduler" - the list of valid names
+will be displayed, with the currently selected scheduler in brackets:
+# cat /sys/block/hda/queue/scheduler
+noop anticipatory deadline [cfq]
+# echo anticipatory > /sys/block/hda/queue/scheduler
+# cat /sys/block/hda/queue/scheduler
+noop [anticipatory] deadline cfq