[lkml]   [2004]   [Aug]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [patch] voluntary-preempt-
On Sun, 2004-08-15 at 22:43, Ingo Molnar wrote:
> * Lee Revell <> wrote:
> >
> nice. (What is the difference between the left-hand and the right-hand
> graphs - why is the right-hand side one 'wider'?)

The right hand graph is logarithmically scaled on the y axis (set
logscale y in gnuplot). Some of the latencies are rare enough to not
show up at all on the linear scale, like the peak in the 400s.

> > The peaks on this graph should correspond directly to the length of
> > the non-preemptible critical section reported by Ingo's latency
> > tracer. I think the large peak around 580-600usecs is caused by the
> > extract_entropy issue (which can be hit by regular processes and
> > ksoftirqd), and the large peak around 80-100 by the XFree86 unmap_vmas
> > issue, as the times match and these are by far the most common
> > reported in latency_trace.
> just to check this theory, could you make __check_and_rekey() an empty
> function? This should still produce a working random driver, albeit at
> much reduced entropy. If these latencies have a relationship to the
> mlockall() issue then this change should have an effect.

Sure, will try this next.


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: 2005-03-22 14:05    [W:0.485 / U:35.052 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site