Re: [PATCH] speed up SATA

Jens Axboe
2004-03-30T13:49:52Z

On Tue, Mar 30 2004, Marc Bevand wrote:
> On 30 Mar 2004, Jens Axboe wrote:
> | On Tue, Mar 30 2004, Marc Bevand wrote:
> | [...]
> | > As other people were complaining that the 32MB max request size might be too
> | > high, I did give a try to 1MB (by replacing "65534" by "2046" in the patch).
> | > There is no visible differences between 32MB and 1MB.
> |
> | As suspected. BTW, you want to use 2048 there, not 2046. The 64K-2
> | (which could be 64K-1) is just due to ->max_sectors being an unsigned
> | short currently.
>
> Okay, I thought the 2 sectors were used to store some extra
> informations.
>
> I also forgot to mention that there does not seem to have any
> *latency* differences between 32MB and 1MB. Strange...

That's because you are not generating requests that big anyways.

--
Jens Axboe