Re: Poor interactive performance with I/O loads with fsync()ing

[Arjan van de Ven]

On Sat, 27 Mar 2010 18:20:37 -0700 (PDT)
Ben Gamari <bgamari.foss@xxxxxxxxx> wrote:

> Hey all,
> 
> I have posted another profile[1] from an incident yesterday. As you
> can see, both swapper and init (strange?) show up prominently in the
> profile. Moreover, most processes seem to be in blk_peek_request a
> disturbingly large percentage of the time. Both of these profiles
> were taken with 2.6.34-rc kernels.
> 
> Anyone have any ideas on how to proceed? Is more profile data
> necessary? Are the existing profiles at all useful? Thanks,


profiles tend to be about cpu usage... and are rather poor to deal with
anything IO related.

latencytop might get closer in giving useful information....

(btw some general suggestion.. make sure you're using noatime or
relatime as mount option) 
-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/