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| -rw-r--r-- | Documentation/block/switching-sched.txt | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/Documentation/block/switching-sched.txt b/Documentation/block/switching-sched.txt new file mode 100644 index 00000000000..5fa130a6753 --- /dev/null +++ b/Documentation/block/switching-sched.txt @@ -0,0 +1,22 @@ +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 |