[lkml]   [2008]   [Sep]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: Unified tracing buffer
    Steven Rostedt wrote:
    > But, with that, with a global atomic counter, and the following trace:
    > cpu 0: trace_point_a
    > cpu 1: trace_point_c
    > cpu 0: trace_point_b
    > cpu 1: trace_point_d
    > Could the event a really come after event d, even though we already hit
    > event b?

    yes, if event c is an interrupt event :-).

    cpu 0 cpu 1
    hit event d
    hit event a
    log event a
    irq event c
    log event c
    hit event b
    log event b
    log event d

    so, I think if we really need to order events, we have to stop
    irq right after hitting an event.

    Anyway, in most case, I think it works, but as accurate as
    synchronized-TSC if hardware supports it.

    Thank you,

    Masami Hiramatsu

    Software Engineer
    Hitachi Computer Products (America) Inc.
    Software Solutions Division


     \ /
      Last update: 2008-09-23 06:15    [W:0.019 / U:12.820 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site