Messages in this thread | | | Date | Fri, 03 Dec 2004 11:45:03 +0100 | From | "Prakash K. Cheemplavam" <> | Subject | Re: Time sliced CFQ io scheduler |
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Jens Axboe schrieb: > On Fri, Dec 03 2004, Jens Axboe wrote: > >>Funky. It looks like another case of the io scheduler being at the wrong >>place - if raid sends dependent reads to different drives, it screws up >>the io scheduling. The right way to fix that would be to io scheduler >>before raid (reverse of what we do now), but that is a lot of work. A >>hack would be to try and tie processes to one md component for periods >>of time, sort of like cfq slicing. > > > It makes sense to split the slice period for sync and async requests, > since async requests usually get a lot of requests queued in a short > period of time. Might even make sense to introduce a slice_rq value as > well, limiting the number of requests queued in a given slice. > > But at least this patch lets you set slice_sync and slice_async > seperately, if you want to experiement.
An idea, which values I should try?
In generell I rather have the impression the problem I am experiencing is not the problem of the io scheduler alone or why do all show the same problem?
BTW, I just did my little test on the ide drive and it shows the same problem, so it is not sata / libata related.
Prakash [unhandled content-type:application/pgp-signature] | |