Re: [PATCHSET] Linux 2.4.20-jam0

Andrew Morton
2002-11-30T22:08:27Z

"J.A. Magallon" wrote:
>
> On 2002.11.30 Andrew Morton wrote:
> >"J.A. Magallon" wrote:
> >>
> >> - Orlov inode allocator for 2.4
> >
> >The Orlov allocator in 2.5 has caused a tremendous performance regression
> >in dbench-on-ext3/ordered-on-scsi.
> >
> >I don't know why yet - I doubt if it's due to the allocator itself - more
> >likely an IO scheduling bug in ext3, or a bug in the 2.5 elevator.
> >
> >There is no such regression on IDE - presumably write caching is covering
> >up the problem.
> >
>
> Is there any way I can test that ? I have all scsi drives and can
> for example remount with 'orlov' or 'oldalloc'...

It is specific to SMP, and for some reason doesn't manifest with
IDE hardware.

See
http://sourceforge.net/mailarchive/forum.php?thread_id=1365460&forum_id=6379
for the analysis.