Re: [PATCH 0/2] perf stat: add per-core count aggregation

From: Andi Kleen
Date: Tue Feb 12 2013 - 12:23:27 EST


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?

The idea itself is useful.

> 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?
>
> # 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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