[lkml]   [2007]   [Mar]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: SMP performance degradation with sysbench
On Tue, Mar 13, 2007 at 09:06:14PM +1100, Nick Piggin wrote:
> Well ignoring the HT issue, I was seeing lots of idle time simply
> because userspace could not keep up enough load to the scheduler.
> There simply were fewer runnable tasks than CPU cores.

When you said idle I thought idle and not waiting for I/O. Waiting for
I/O would be hardly a kernel issue ;). If they're not waiting for I/O
and they're not scheduling in userland with nanosleep/pause, the cpu
shouldn't go idle. Even if they're calling sched_yield in a loop the
cpu should account for zero idle time as far as I can tell.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2007-03-13 11:35    [W:0.065 / U:7.040 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site