Messages in this thread |  | | | Subject | Re: Possible bug from kernel 2.6.22 and above | | From | Peter Zijlstra <> | | Date | Wed, 05 Dec 2007 21:36:42 +0100 |
On Wed, 2007-11-21 at 15:34 -0500, Jie Chen wrote:
> It is clearly that the synchronization overhead increases as the number
> of threads increases in the kernel 2.6.21. But the synchronization
> overhead actually decreases as the number of threads increases in the
> kernel 2.6.23.8 (We observed the same behavior on kernel 2.6.22 as
> well). This certainly is not a correct behavior. The kernels are
> configured with CONFIG_SMP, CONFIG_NUMA, CONFIG_SCHED_MC,
> CONFIG_PREEMPT_NONE, CONFIG_DISCONTIGMEM set. The complete kernel
> configuration file is in the attachment of this e-mail.
>
> From what we have read, there was a new scheduler (CFS) appeared from
> 2.6.22. We are not sure whether the above behavior is caused by the new
> scheduler.
If I read this correctly, you say that: .22 is the first bad one right?
The new scheduler (CFS) was introduced in .23, so it seems another
change would be responsible for this.
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