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    SubjectRe: [PATCH] perf: make perf.data more self-descriptive (v5)


    On 09/23/2011 07:40 AM, Stephane Eranian wrote:
    >
    >
    > On Fri, Sep 23, 2011 at 3:36 PM, David Ahern <dsahern@gmail.com
    > <mailto:dsahern@gmail.com>> wrote:
    >
    >
    >
    > On 09/23/2011 03:04 AM, Stephane Eranian wrote:
    > > On Fri, Sep 23, 2011 at 10:03 AM, Pekka Enberg
    > <penberg@cs.helsinki.fi <mailto:penberg@cs.helsinki.fi>> wrote:
    > >> Hi Stephane!
    > >>
    > >> On Fri, Sep 23, 2011 at 10:31 AM, Stephane Eranian
    > <eranian@google.com <mailto:eranian@google.com>> wrote:
    > >>>> So how important is this information? The output is going to be
    > somewhat
    > >>>> awkward for very large CPU counts... :-)
    > >>>>
    > >>> It is useful to determine how CPUs share caches for instance.
    > >>> It can get large but large, but the meta-data header is not
    > printed by
    > >>> default, you need to request it with the -I option.
    > >>
    > >> Well, sure but it blocks rest of the interesting information too.
    > It seems to me
    > >> that the CPU information could be truncated to some sane limit by
    > default and
    > >> introduce a command line option for users that really want to see
    > all of it.
    > >>
    > > Ok, so here is a proposal:
    > > - reorder the info so one liners appear first
    > > - display the "truncated" info by default (no option)
    > > - truncated: numa topo, cpu topo, stop after 4 cpus/nodes, print msg
    >
    > Earlier I gave an example for a 2 socket, quad-core with hyperthreading
    > (16 cpus total):
    > https://lkml.org/lkml/2011/9/6/355
    > The information is repetitive. It would be better to devise a way to
    > reduce the repetition versus truncate the information.
    >
    >
    > I have modified the patch to NOT print the CPU, NUMA topology by
    > default (but mentioned they are available with the -I option). The
    > other bits of information are displayed systematically (no truncation).
    >
    > What ways would you propose to still print the info is a less-verbose
    > fashion?
    >

    for example, sibling cores:
    # CPU0 sibling cores : 0,2,4,6,8,10,12,14

    you don't need to print that info for CPUs 0,2,4,6,8,10,12,14. Just
    once. Maybe just:

    # CPU sibling cores : 0,2,4,6,8,10,12,14

    Similarly for the threads:
    # CPU sibling threads: 0,8


    That drops the output from 32 lines to 10.

    # CPU sibling cores : 0,2,4,6,8,10,12,14
    # CPU sibling cores : 1,3,5,7,9,11,13,15
    # CPU sibling threads: 0,8
    # CPU sibling threads: 1,9
    # CPU sibling threads: 2,10
    # CPU sibling threads: 3,11
    # CPU sibling threads: 4,12
    # CPU sibling threads: 5,13
    # CPU sibling threads: 6,14
    # CPU sibling threads: 7,15



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