On Wed, 2 Sep 2009 12:23:59 -0500
"Madhusudhan" <madhu.cr@xxxxxx> wrote:
> Hi,
>
> Has anyone monitored the cpu utilization percentage when a MMC/SD card is in
> use? I have noticed that mmc_queue_thread "mmcqd" consumes a lot of cpu
> cycles in a periodic fashion. What I mean here is that I see spikes of high
> cpu utilization due to mmcqd. There will a cp or similar which will be
> already consuming cpu to transfer data to the MMC/SD device. Further mmcqd
> increases that load randomly to a high number.
>
> Has anyone seen similar behavior? Any thoughts?
>
My guess would be that the omap driver doesn't (cannot?) use the
hardware to wait for busy to end, so the system must poll.
Anything better than that guess will require some profiling. :)
Rgds
--
-- Pierre Ossman
WARNING: This correspondence is being monitored by the
Swedish government. Make sure your server uses encryption
for SMTP traffic and consider using PGP for end-to-end
encryption.
Attachment:
signature.asc
Description: PGP signature
