lkml.org 
[lkml]   [2009]   [Mar]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 13/15] perf_counter: provide generic callchain bits
    Corey Ashford writes:

    > If this is the case, what is the exact meaning of PERF_COUNTER_SIMPLE
    > now? and PERF_COUNTER_GROUP? One simplification would be that reading
    > the fd of a group leader would always read up all of the counters in the
    > group (along with their enabled and running times if those bits are
    > set), and that reading a single counter's fd would yield only that
    > counter's values and times (if enabled). In effect, these two values,
    > PERF_COUNTER_GROUP and PERF_COUNTER_SIMPLE would no longer be necessary
    > at all. Other bits would be used to determine what's in the mmap'd samples.

    Now that events are only read through mmap, it's quite simple -
    hw_event.read_format controls what read() gives you, and
    hw_event.record_type controls what gets put into the pages that you
    get with mmap.

    Currently read_format and record_type don't use the same set of bit
    definitions. Maybe they should? I don't have a strong feeling about
    it, but that might be a nice simplification.

    Paul.


    \
     
     \ /
      Last update: 2009-03-31 11:15    [W:0.021 / U:208.460 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site