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-rw-r--r-- | Documentation/block/switching-sched.txt | 22 |
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1 | As of the Linux 2.6.10 kernel, it is now possible to change the | ||
2 | IO scheduler for a given block device on the fly (thus making it possible, | ||
3 | for instance, to set the CFQ scheduler for the system default, but | ||
4 | set a specific device to use the anticipatory or noop schedulers - which | ||
5 | can improve that device's throughput). | ||
6 | |||
7 | To set a specific scheduler, simply do this: | ||
8 | |||
9 | echo SCHEDNAME > /sys/block/DEV/queue/scheduler | ||
10 | |||
11 | where SCHEDNAME is the name of a defined IO scheduler, and DEV is the | ||
12 | device name (hda, hdb, sga, or whatever you happen to have). | ||
13 | |||
14 | The list of defined schedulers can be found by simply doing | ||
15 | a "cat /sys/block/DEV/queue/scheduler" - the list of valid names | ||
16 | will be displayed, with the currently selected scheduler in brackets: | ||
17 | |||
18 | # cat /sys/block/hda/queue/scheduler | ||
19 | noop anticipatory deadline [cfq] | ||
20 | # echo anticipatory > /sys/block/hda/queue/scheduler | ||
21 | # cat /sys/block/hda/queue/scheduler | ||
22 | noop [anticipatory] deadline cfq | ||