Re: DBT-2 anticipatory scheduler and filesystem results with 2.6.1

From: Andrew Morton
Date: Mon Jan 19 2004 - 23:39:33 EST


markw@xxxxxxxx wrote:
>
> I ran some dbt-2 tests against 5 filesystems with 2.6.1-mm4 and 2.6.1. I
> see a degradation from 0 to 7% in throughput.

-mm4 also had readahead changes which will adversely impact database-style
workloads. I'd suggest that you revert

ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.1/2.6.1-mm4/broken-out/readahead-revert-lazy-readahead.patch

and retest.

We reverted lazy readahead because it broke NFS linear reads and was doing
the wrong thing anyway. We need to come up with something else for
database-style workloads.

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