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
