[lkml]   [2007]   [Dec]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: RFC: remove __read_mostly
    On Fri, 14 Dec 2007 01:33:45 +0100 Andi Kleen <> wrote:

    > Kyle McMartin <> writes:
    > > I'd bet, in the __read_mostly case at least, that there's no
    > > improvement in almost all cases.
    > I bet you're wrong. Cache line behaviour is critical, much more
    > than pipeline behaviour (which unlikely affects). That is because
    > if you eat a cache miss it gets really expensive, which e.g.
    > a mispredicted jump is relatively cheap in comparison. We're talking
    > one or more orders of magnitude.

    So... once we've moved all read-mostly variables into __read_mostly, what
    is left behind in bss?

    All the write-often variables. All optimally packed together to nicely
    maximise cacheline sharing.

     \ /
      Last update: 2007-12-17 11:37    [W:0.029 / U:5.096 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site