Re: [PATCH 8/9] perf report: Add report.percent-limit config variable

From: Pekka Enberg
Date: Thu May 16 2013 - 03:35:02 EST

On 05/15/2013 01:08 PM, Namhyung Kim wrote:
Hi Pekka,

On Tue, 14 May 2013 14:05:38 +0300, Pekka Enberg wrote:
On Tue, May 14, 2013 at 5:09 AM, Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
From: Namhyung Kim <>

Now an user can set a default value of --percent-limit option into the
perfconfig file.

$ cat ~/.perfconfig
percent-limit = 0.1

Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>

I'm not totally convinced this is useful. The limit is about "what is
significant" and that depends on what you are trying to measure.
There's an (absolute) lower limit somewhere between 0.1 and 1.0 but I
think we can just pick a reasonable default and let people use the
command line switch if they want to override it.

If the limit depends on what is measured, what should be the reasonable
default value? I just don't know..

I agree that we should pick a default but the config variable doesn't
harm anything in this case too. Some users might not agree with our
default for their cases and want to use other value.

But I'm not insist on it so strongly, I just gave another way.. ;)

I'd go for default value of 1.0 first and if people complain, drop it to 0.1. But I guess it's safer to add your config option thingy just in case:

Acked-by: Pekka Enberg <penberg@xxxxxxxxxx>

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