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    SubjectRe: [PATCH 0/2] perf stat: add per-core count aggregation
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    On Tue, Feb 12, 2013 at 6:23 PM, Andi Kleen <ak@linux.intel.com> wrote:
    > On Tue, Feb 12, 2013 at 03:09:26PM +0100, Stephane Eranian wrote:
    >> This patch series contains improvement to the aggregation support
    >> in perf stat.
    >>
    >> First, the aggregation code is refactored and a aggr_mode enum
    >> is defined. There is also an important bug fix for the existing
    >> per-socket aggregation.
    >>
    >> Second, the patch adds a new --aggr-core option to perf stat.
    >
    > Perhaps it's just me, but the option name is ugly (and sounds
    > aggressive)
    >
    > --per-core perhaps?
    >
    I chose that name to be similar to ---aggr-socket.
    But we could change both at this point.


    > The idea itself is useful.
    >
    Yes, it is.

    >> It aggregates counts per physical core and becomes useful on
    >> systems with hyper-threading. The cores are presented per
    >> socket: S0-C1, means socket 0 core 1. Note that the core number
    >> represents its physical core id. As such, numbers may not always
    >> be contiguous. All of this is based on topology information available
    >> in sysfs.
    >>
    >> Per-core aggregation can be combined with interval printing:
    >
    > FWIW this would be much nicer if stat had a Kevents or Mevents mode.
    > Usually we don't need all the digits. But that could be added separately
    >
    > Does it work for multiple events in parallel?

    Yes, it does. It's all regular perf stat.


    >>
    >> # perf stat -a --aggr-core -I 1000 -e cycles sleep 100
    >> # time core cpus counts events
    >> 1.000101160 S0-C0 2 6,051,254,899 cycles
    >> 1.000101160 S0-C1 2 6,379,230,776 cycles
    >> 1.000101160 S0-C2 2 6,480,268,471 cycles
    >> 1.000101160 S0-C3 2 6,110,514,321 cycles
    >> 2.000663750 S0-C0 2 6,572,533,016 cycles
    >> 2.000663750 S0-C1 2 6,378,623,674 cycles
    >> 2.000663750 S0-C2 2 6,264,127,589 cycles
    >> 2.000663750 S0-C3 2 6,305,346,613 cycles
    >
    > -Andi


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