lkml.org 
[lkml]   [2005]   [Jan]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: pipe performance regression on ia64
    >>>>> On Wed, 19 Jan 2005 23:43:45 +1100, Nick Piggin <nickpiggin@yahoo.com.au> said:

    Nick> Oh that's quite true. A bad score on SMP on the pipe benchmark
    Nick> does not mean anything is broken.

    Nick> And IMO, probably many (most?) lmbench tests should be run
    Nick> with all processes bound to the same CPU on SMP systems to get
    Nick> the best repeatability and an indication of the basic serial
    Nick> speed of the operation (which AFAIK is what they aim to
    Nick> measure).

    We need to keep an eye on both the intra- and the inter-cpu
    pipe-bandwidth and should measure them explicitly. The problem is
    that at the moment, we get one, the other, or a mixture of the two,
    subject to the vagaries of the scheduler. If we could reliably
    measure both intra and inter-cpu cases, we may well find new
    optimization opportunities (I'm almost certain that's the case for the
    cross-cpu case; which is probably the more important case, actually).

    --david
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 14:09    [W:0.024 / U:0.316 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site