Performance regression in IO scheduler still there

Jan Kara
2009-10-26T17:20:10Z

Hi,

I took time and remeasured tiobench results on recent kernel. A short
conclusion is that there is still a performance regression which I reported
few months ago. The machine is Intel 2 CPU with 2 GB RAM and plain SATA
drive. tiobench sequential write performance numbers with 16 threads:
2.6.29: AVG STDERR
37.80 38.54 39.48 -> 38.606667 0.687475

2.6.32-rc5:
37.36 36.41 36.61 -> 36.793333 0.408928

So about 5% regression. The regression happened sometime between 2.6.29 and
2.6.30 and stays the same since then... With deadline scheduler, there's
no regression. Shouldn't we do something about it?

Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR