On Wed, May 18, 2011 at 3:32 PM, Christian Robottom Reis kiko@linaro.org wrote:
On Wed, May 18, 2011 at 02:53:22PM +0100, Dave Martin wrote:
Hi,
On Tue, May 17, 2011 at 5:53 PM, Tom Gall tom.gall@linaro.org wrote:
Hi All,
From UDS last week I was inspired to run bootchart on our Linaru Ubuntu-desktop LEB.
I collected the data on my panda board using the daily snapshot from last week.
From a very quick examination of the output, it would seem we are IO bound.
I've created a quick wiki page about BootChart and attached the data I've gathered.
Interesting.
Due to the poor I/O throughput, it looks a bit like we might be hitting the known SD card write behaviour issues; mounting with noatime and/or journaling disabled (noload for ext4) might also make a difference.
Um, why are we writing to anything on boot up?
I'm just guessing there might be _some_ writes -- from atime updates, logfile writes and corresponding journal writes for example -- and if so there then it may be having a significant impact. We could check the actual I/O to be sure.
On graphical login, various daemons may scribble in dot dirs and databases -- find -mmin could help here.
(Or is it an artifact of recording the BootChart data?)
Possible ... I would hope that the boothchart data goes into a ramfs to avoid that. Worth checking, though.
Cheers ---Dave