Re: Mainline kernel OLTP performance update

Jens Axboe
2009-01-27T08:29:58Z

On Mon, Jan 26 2009, Chilukuri, Harita wrote:
> Jens, we did test the patch that disables the whole stats. We get 0.5% gain with this patch on 2.6.29-rc2 comparing to 2.6.29-rc2-disbale_part_stats
>
> Below is the description of the result:
>
> Linux OLTP Performance summary
> Kernel# Speedup(x) Intr/s CtxSw/s us% sys% idle% iowait%
> 2.6.29-rc2-disbale_partition_stats 1.000 30413 42582 74 25 0 0
> 2.6.29-rc2-disable_all 1.005 30401 42656 74 25 0 0
>
> Server configurations:
> Intel Xeon Quad-core 2.0GHz 2 cpus/8 cores/8 threads
> 64GB memory, 3 qle2462 FC HBA, 450 spindles (30 logical units)

OK, so about the same, which means the lookup is likely the expensive
bit. I have merged this patch:

http://git.kernel.dk/?p=linux-2.6-block.git;a=commit;h=e5b74b703da41fab060adc335a0b98fa5a5ea61d

which exposes an 'iostats' toggle that allows users to disable disk
statistics completely.

--
Jens Axboe