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Date: Wed, 2 Dec 2009 10:50:12 +0100
From: Ingo Molnar <mingo@elte.hu>
To: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, Oleg Nesterov <oleg@redhat.com>,
       KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
       linux-kernel@vger.kernel.org, dhowells@redhat.com,
       hidehiro.kawai.ez@hitachi.com, lethal@linux-sh.org, roland@redhat.com,
       vapier@gentoo.org, Takahiro Yasui <tyasui@redhat.com>
Subject: Re: [PATCH v2] mm: Introduce coredump parameter structure
Message-ID: <20091202095012.GD22654@elte.hu>
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* Masami Hiramatsu <mhiramat@redhat.com> wrote:

> Andrew Morton wrote:
> >On Sat, 28 Nov 2009 23:41:19 -0500
> >Masami Hiramatsu<mhiramat@redhat.com>  wrote:
> >
> >>Introduce coredump parameter data structure (struct coredump_params)
> >>for simplifying binfmt->core_dump() arguments.
> >>
> >>Changes in v2:
> >>    - Don't remove DUMP_WRITE() macro.
> >
> >What is the reason for this change?
> >
> >Please always include both the "what" and the "why" in changelog text.
> 
> I see.

I think Andrew wanted to see a longer explanation about precisely what 
we need for these tracepoints and what the various specific usecases are 
to utilize it.

I.e. a basic cost/benefit analysis is needed. By looking at the patch we 
can see the cost - but you have to counter-balance that with enough 
stuff in the 'benefits' column of the equation.

	Ingo