[lkml]   [2004]   [Jan]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: Request: I/O request recording
Andrew Morton wrote:
> You could certainly do that. Given disk block #N you need to search all
> files on the disk asking "who owns this block". The FIBMAP ioctl can be
> used on most filesystems (ext2, ext3, others..) to find out which blocks a
> file is using. See bmap.c in
> Unfortunately you cannot determine a directory's blocks in this way.
> Ext3's directories live in the /dev/hda1 pagecache anyway. ext2's
> directories each have their own pagecache.

OK, I've written something that does this (but only correctly for ext3).
I've put it here:

I haven't had the opportunity to do good measurements, so I don't really
know if it even increases performance. If anyone feels like benchmarking
this, I'd be very happy to hear from you. I don't really expect
performance increases, as the bootup scripts seem to have enough
processing to do to keep the system busy even without disk I/O. I wonder
if it might make a difference on a faster processor though, my system's
kind of sluggish by today's standards.

-- Bart
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 14:00    [W:0.066 / U:23.740 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site