RE: Lockless page cache test results

Chen, Kenneth W
2006-04-27T05:39:32Z

Jens Axboe wrote on Wednesday, April 26, 2006 12:46 PM
> > It's interesting, single threaded performance is down a little. Is
> > this significant? In some other results you showed me with 3 splices
> > each running on their own file (ie. no tree_lock contention), lockless
> > looked slightly faster on the same machine.
>
> I can do the same numbers on a 2-way em64t for comparison, that should
> get us a little better coverage.

I throw the lockless patch and Jens splice-bench into our benchmark harness,
here are the numbers I collected, on the following hardware:

(1) 2P Intel Xeon, 3.4 GHz/HT, 2M L2
(2) 4P Intel Xeon, 3.0 GHz/HT, 8M L3
(3) 4P Intel Xeon, 3.0 GHz/DC/HT, 2M L2 (per core)

Here are the graph:

(1) 2P Intel Xeon, 3.4 GHz/HT, 2M L2
http://kernel-perf.sourceforge.net/splice/2P-3.4Ghz.png

(2) 4P Intel Xeon, 3.0 GHz/HT, 8M L3
http://kernel-perf.sourceforge.net/splice/4P-3.0Ghz.png

(3) 4P Intel Xeon, 3.0 GHz/DC/HT, 2M L2 (per core)
http://kernel-perf.sourceforge.net/splice/4P-3.0Ghz-DCHT.png

(4) everything on one graph:
http://kernel-perf.sourceforge.net/splice/splice.png

- Ken