Re: slow io_submit

[Raz Ben-Jehuda(caro)]

On 12/1/06, Jens Axboe <jens.axboe@xxxxxxxxxx> wrote:
> On Fri, Dec 01 2006, Raz Ben-Jehuda(caro) wrote:
> > Jens suparna hello
> >
> > I have managed to understand why io_submit is sometimes very slow.
> > It is because the device is plugged once too many io's are being sent.
> > I have conducted a simple test with nr_request to default value of 128
> > and and 256.
> > and it proved to be correct.
>
> I don't understand your email. The device is plugged when it is empty,
> not when it has emptied the request list.

first , i am not top posting you.
I made a mistake and associated plugging with a full queue.

> > I would truely appreciate your comment on this.
>
> On what? :-)
>
> If it's no blocking and returning EAGAIN instead, then I agree this is
> what should eventually happen.
Who returns EGAIN to whom ?   I am not sure i understand what you mean here.

> Right now nobody is working on that
> afaik, so it's not something that will hit the next kernel.

thank you
raz

> --
> Jens Axboe


--
Raz
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