On Thu, 2004-11-18 at 08:36 +0100, Arjan van de Ven wrote:
> There's a 20 MB load of files in your readahead list and
they are being
> read for 15 seconds. I guess a 26.60 MB/sec 'hdparm -t' suggests room
> for improvement? Note that this is on a 4200 RPM drive.
hmm yeah there ought to be room; I'll need to think about how to use that
though.
Yeah I guess the fact that disk caches are loaded on a per-file basis
doesn't help either. Because in theory: stat-ing your list takes about
3 sec and readahead on a tarball is instantaneous (both of course
without boot-time readahead).
(A kick in the dark probably, but I'm thinking a contiguous readahead
cache file kept updated with the changed files only.)
One question: was the drive (light) mostly quiet when readahead was
finished ?
Well there are occasional flashes, even if I turn off synchronous
logging (which wasn't the case when I posted the chart). I guess I'd
have to tailor the list first.
BTW, some time ago (
http://kerneltrap.org/node/view/2157) you mentioned
11,000 files being read during boot. This list only contains 923. Are
all the rest gnome-related?
--
Ziga