lkml.org 
[lkml]   [2010]   [Sep]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 0/8] sdhci: Move real work out of an atomic context
Hi Anton,

On Thu, Sep 09, 2010 at 01:57:50AM +0400, Anton Vorontsov wrote:
> Thanks!
>
> Would be also great if you could point out which patch causes
> most of the performance drop (if any)?
>
> Albert, if you could find time, can you also "bisect" the
> patchset? I wouldn't want to buy Nintendo WII just to debug the
> perf regression. ;-) FWIW, I tried to disable multiblock
> read/writes and test with SD cards, and still didn't notice
> any performance drops.
>
> Maybe it's SDIO IRQs that cause the performance drop for the
> WII case, as we delay them a little bit? Or it could be the
> patch that introduces threaded IRQ handler in whole causes
> it. If so, I guess we'd need to move some of the processing to
> the real IRQ context, keeping the handler lockless (if
> possible) or introducing a very fine grained locking.

I didn't know anything about a reported performance drop, and I don't
think Andrew did either -- Albert's test results don't seem to have
made it to this list, or anywhere else that I can see. Could you
link to/repost his comments?

(I'll be testing with libertas, so that will stress-test SDIO IRQs.)

Thanks,

--
Chris Ball <cjb@laptop.org> <http://printf.net/>
One Laptop Per Child


\
 
 \ /
  Last update: 2010-09-09 00:09    [from the cache]
©2003-2011 Jasper Spaans