Re: [patch] voluntary-preempt-2.6.8.1-P9

Lee Revell
2004-08-25T03:22:43Z

On Tue, 2004-08-24 at 23:17, K.R. Foley wrote:
> Ingo Molnar wrote:
> >
> > http://redhat.com/~mingo/voluntary-preempt/voluntary-preempt-2.6.8.1-P9
> >

> latency trace of ~148 usec in scsi_request? I don't know if this is real
> or not. Note the 79 usec here:
>
> 00000001 0.107ms (+0.079ms): sd_init_command (scsi_prep_fn)
>
> Entire trace is here:
>
> http://www.cybsft.com/testresults/2.6.8.1-P9/latency_trace7.txt
>
>
> Is this possible? This is not the first time I have seen this. There is
> another one here:
>
> http://www.cybsft.com/testresults/2.6.8.1-P9/latency_trace5.txt
>

This looks like a real latency. What is
/sys/block/sdX/queue/max_sectors_kb set to? Does lowering it help?

Lee