Messages in this thread | | | Subject | Re: Block I/O Schedulers: Can they be made selectable/device? @runtime? | From | Valdis.Kletnieks@vt ... | Date | Sun, 26 Mar 2006 02:06:55 -0500 |
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On Sat, 25 Mar 2006 22:41:00 PST, Linda Walsh said: > Is it still the case that block I/O schedulers (AS, CFQ, etc.) > are only selectable at boot time?
Hasn't been for quite some time. CPU schedulers are stuck at boot time, even if you have the 'plugsched' patch (and if you don't, you're stuck with the one scheduler in-tree currently). There was a patch posted a few days ago that allowed on-the-fly changing of plugsched, but that's still too bleeding edge even for me... ;)
> How difficult would it be to allow multiple, concurrent I/O > schedulers running on different block devices?
From my /etc/rc.local:
echo cfq > /sys/block/hda/queue/scheduler echo noop > /sys/block/hdb/queue/scheduler
(hda is a real disk with ext3 partitions on it, hdb is a DVD/CD/RW that almost always has exactly one process reading or writing to it at a given time, so doing things in the order requested is just fine).
Simple enough? ;)
(This *does* require that you built more than one scheduler, and possibly to make sure they're loaded if you managed to build them modular...) [unhandled content-type:application/pgp-signature] | |