[maemo-developers] [maemo-developers] Re: Device slowness without anything using CPU (was: What kind of tools and utilities you want in ARM)

[From: Marius Gedminas]

On Wed, Feb 07, 2007 at 03:42:57PM +0200, Eero Tamminen wrote:
> ext Marius Gedminas wrote:
> >Vmstat is useful to see why the tablet is sometimes not responsive
> >(e.g. while installing a package), when the CPU applet shows 0% usage.
> 
> But the device becomes responsive again once the package installation
> from the MMC completes, right?

Yes.  And the pause occurs pretty rarely.  I think that's when the jffs2
log fills up and the garbage collector has to kick in.

I kept upgrading FBReader after each release, and mostly the upgrade was
fast, but sometimes I had to wait several minutes.  That was scary the
first time it happened.

> (If not, what's the MMC/SD card model and manufacturer?)

(Package installation writes files into the internal flash.  And I
install packages downloaded from the internet, not from an MMC card.)

> (The answer is a storm of interrupts, dealing with flash memory.)
> 
> Hm.  I guess one could monitor these from /proc/interrupts or
> /proc/stat, but vmstat is indeed easier... :-)

Actually, now that I know this is normal, vmstat is no longer necessary
:-)

Marius Gedminas
-- 
To err is human... to really foul up requires the root password.
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