Re: 2.6.19-rc4: known unfixed regressions (v3)

Eric W. Biederman
2006-11-05T15:22:48Z

Adrian Bunk <bunk@stusta.de> writes:

>
> Subject : x86_64: NR_IRQ increase causes 11.5% slowdown
> in lmbench's fork benchmark
> References : http://lkml.org/lkml/2006/11/2/192
> Submitter : Tim Chen <tim.c.chen@linux.intel.com>
> Caused-By : Eric W. Biederman <ebiederm@xmission.com>
> commit 550f2299ac8ffaba943cf211380d3a8d3fa75301
> Handled-By : Eric W. Biederman <ebiederm@xmission.com>
> Andi Kleen <ak@suse.de>
> Status : problem is being debugged

Currently I'm at a loss why the cross cpu fork lm_bench numbers should get
worse when you simply double NR_IRQS. As far as I can determine nothing
on that code path is directly affected by that change.

Eric