Messages in this thread | | | Date | Thu, 03 Jun 2004 17:56:17 -0600 | From | "Jeff V. Merkey" <> | Subject | Re: submit_bh leaves interrupts on upon return |
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Linus Torvalds wrote:
>On Thu, 3 Jun 2004, Jens Axboe wrote: > > > >>On Thu, Jun 03 2004, Jeff V. Merkey wrote: >> >> >>>Sounds like I need to move to 2.6. I noticed the elevator is coalescing >>>quite well, and since I am posting mostly continguous runs of sectors, >>>what ends up at the adapter level would probably not change much much >>>between 2.4 and 2.6 since I am maxing out the driver request queues as >>>it is (255 pending requests of 32 scatter/gather elements of 256 sector >>>runs). 2.6 might help but I suspect it will only help alleviate the >>>submission overhead, and not make much difference on performance since >>>the 3Ware card does have an upward limit on outstanding I/O requests. >>> >>> >>That's correct, it just helps you diminish the submission overhead by >>pushing down 256 sector entities in one go. So as long as you're io >>bound it won't give you better io performance, of course. If you are >>doing 400MiB/sec it should help you out, though. >> >> > >Well, if Jeff does almost exclusively contiguous stuff and submits them in >order, then the coalescing will make sure that even on 2.4.x the queues >don't get too long, and he probably won't see the pathological cases. > > Linus >- > Linus,
This seems to be the case.
Jeff
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