Andrew Morton wrote:
> Well that's pretty bad, isn't it?
We could have bought a much cheaper controller and slower disks ;-)
> - Disable CONFIG_HIGHMEM
That seems to have no effect on performance. Btw., the 64GB support in
2.4.10 seemed to be buggy ("0-order allocation failed", then the DB
crashed), so we were using the 4GB setting.
> - Try linux-2.4.13
This helped - now performance is up to par with 2.2.19 (~ 85MB/s) - thanks!
> - Profile the kernel. [...] With something like:
> ~/kern-prof.sh cp some_huge_file /dev/null
I tried this, but with
dd if=/dev/sda of=/dev/null bs=1024k count=3000
(the fs is too slow - so "cp" peaks out at 17MB/s!)
The result (last 4 lines):
c01388fc try_to_free_buffers 55 0.1511
c0128b10 file_read_actor 1179 14.0357
c01053b0 default_idle 6784 130.4615
00000000 total 8695 0.0065
Does this suggest that the kernel isn't the bottleneck?
Regards,
Marinos
-- Marinos Yannikos, CEO Preisvergleich Internet Services AG Franzensbrückenstraße 8/2/16, A-1020 Wien Tel./Fax: (+431) 5811609-52/-55- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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