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Date: Tue, 12 Nov 2013 23:38:00 +0200
From: Pekka Enberg <penberg@iki.fi>
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To: David Ahern <dsahern@gmail.com>, Ingo Molnar <mingo@kernel.org>,
        Pekka Enberg <penberg@kernel.org>
CC: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Subject: Re: [PATCH] perf trace: Simplify '--summary' output
References: <1384267334-18953-1-git-send-email-penberg@kernel.org> <20131112213334.GF25913@gmail.com> <52829F4F.6070800@gmail.com>
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On 11/12/13 11:36 PM, David Ahern wrote:
> On 11/12/13, 2:33 PM, Ingo Molnar wrote:
>>> >  Summary of events:
>>> >
>>> >  dbus-daemon (555), 10 events, 0.0%, 0.000 msec
>>> >
>>> > msec/call
>>> >    syscall            calls      min      avg      max stddev
>>> >    --------------- -------- -------- -------- -------- ------
>>> >    sendmsg                2    0.002    0.005    0.008 55.00
>>> >    recvmsg                2    0.002    0.003    0.005 44.00
>>> >    epoll_wait             1    0.000    0.000    0.000 0.00
>> In what units is stddev? Percentage? If yes then it might be useful to
>> output it as %. [and probably to restrict precision to a single digit,
>> standard deviations are rarely more accurate than 0.1%.]
>>
>
> %. That was dropped in the recent output change.

Sorry about that. Why do we show them in percentages, btw? Standard 
deviation is usually represented in the same unit as the data to make it 
readable.

                         Pekka