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Date: Mon, 5 Aug 2013 16:45:44 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Alex Thorlton <athorlton@sgi.com>, linux-kernel@vger.kernel.org,
        Ingo Molnar <mingo@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Mel Gorman <mgorman@suse.de>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Rik van Riel <riel@redhat.com>, Johannes Weiner <hannes@cmpxchg.org>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Sedat Dilek <sedat.dilek@gmail.com>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Dave Jones <davej@redhat.com>,
        Michael Kerrisk <mtk.manpages@gmail.com>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        David Howells <dhowells@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
        Kees Cook <keescook@chromium.org>, Robin Holt <holt@sgi.com>
Subject: Re: [PATCHv2] Add per-process flag to control thp
Message-ID: <20130805144544.GX27162@twins.programming.kicks-ass.net>
References: <20130802205735.GS26476@sgi.com>
 <20130803170102.GD32568@redhat.com>
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On Sat, Aug 03, 2013 at 07:01:02PM +0200, Oleg Nesterov wrote:
> On 08/02, Alex Thorlton wrote:
> >
> > This patch implements functionality to allow processes to disable the use of
> > transparent hugepages through the prctl syscall.
> >
> > We've determined that some jobs perform significantly better with thp disabled,
> > and we needed a way to control thp on a per-process basis, without relying on
> > madvise.
> 
> Well, I think the changelog should explain why madvise() is bad.

It would be good to describe which jobs and why thp cannot be fixed for
these.