lkml.org 
[lkml]   [2010]   [Dec]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [BUG] 2.6.37-rc3 massive interactivity regression on ARM
    On Fri, 10 Dec 2010, Eric Dumazet wrote:

    > > There is certainly a major difference in that execution of a stream of
    > > instructions on the same cpu is guaranteed to have a coherent view of
    > > the data. That is not affected by interrupts etc.
    > >
    >
    > We dont care of interrupts. We care of doing a transaction over a
    > complex set of data, that cannot be done using an atomic op (or we need
    > a spinlock/mutex/rwlock), and should not because of performance.

    So what? The cpu gives you incoherent view of data somewhere when only
    processing data from a single cpu?

    If you have remote data accesses (loop summing the data?) and you have to
    be concerned about data coherence then you CANNOT use this_cpu_ops since
    they are not guaranteed to be coherent to other processors.


    \
     
     \ /
      Last update: 2010-12-10 22:47    [W:2.130 / U:0.824 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site