Message-ID: <4DFF7E3B.1040404@redhat.com>
Date: Tue, 21 Jun 2011 01:07:07 +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>, Rik van Riel <riel@redhat.com>,
        Johannes Weiner <jweiner@redhat.com>,
        KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>, linux-mm@kvack.org
Subject: Re: [PATCH 1/3] mm: completely disable THP by transparent_hugepage=never
References: <1308587683-2555-1-git-send-email-amwang@redhat.com> <20110620165844.GA9396@suse.de>
In-Reply-To: <20110620165844.GA9396@suse.de>
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于 2011年06月21日 00:58, Mel Gorman 写道:
> On Tue, Jun 21, 2011 at 12:34:28AM +0800, Amerigo Wang wrote:
>> transparent_hugepage=never should mean to disable THP completely,
>> otherwise we don't have a way to disable THP completely.
>> The design is broken.
>>
>
> I don't get why it's broken. Why would the user be prevented from
> enabling it at runtime?
>

We need to a way to totally disable it, right? Otherwise, when I configure
THP in .config, I always have THP initialized even when I pass "=never".

For me, if you don't provide such way to disable it, it is not flexible.

I meet this problem when I try to disable THP in kdump kernel, there is
no user of THP in kdump kernel, THP is a waste for kdump kernel. This is
why I need to find a way to totally disable it.

Thanks.
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