Message-ID: <4DFF8050.9070201@redhat.com>
Date: Tue, 21 Jun 2011 01:16:00 +0800
From: Cong Wang <amwang@redhat.com>
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To: Mel Gorman <mgorman@suse.de>
CC: linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
        Andrea Arcangeli <aarcange@redhat.com>, Mel Gorman <mel@csn.ul.ie>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Rik van Riel <riel@redhat.com>, Johannes Weiner <hannes@cmpxchg.org>,
        KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>, linux-mm@kvack.org
Subject: Re: [PATCH 2/3] mm: make the threshold of enabling THP configurable
References: <1308587683-2555-1-git-send-email-amwang@redhat.com> <1308587683-2555-2-git-send-email-amwang@redhat.com> <20110620165955.GB9396@suse.de>
In-Reply-To: <20110620165955.GB9396@suse.de>
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于 2011年06月21日 00:59, Mel Gorman 写道:
> On Tue, Jun 21, 2011 at 12:34:29AM +0800, Amerigo Wang wrote:
>> Don't hard-code 512M as the threshold in kernel, make it configruable,
>> and set 512M by default.
>>
>
> I'm not seeing the gain here either. This is something that is going to
> be set by distributions and probably never by users. If the default of
> 512 is incorrect, what should it be? Also, the Kconfig help message has
> spelling errors.
>

Sorry for spelling errors, I am not an English speaker.

Hard-coding is almost never a good thing in kernel, enforcing 512
is not good either. Since the default is still 512, I don't think this
will affect much users.

I do agree to improve the help message, like Dave mentioned in his reply,
but I don't like enforcing a hard-coded number in kernel.

BTW, why do you think 512 is suitable for *all* users?

Thanks.
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