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Date: Mon, 2 Mar 2015 15:10:09 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: Mike Kravetz <mike.kravetz@oracle.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Nadia Yvette Chambers <nyc@holomorphy.com>,
        Davidlohr Bueso <davidlohr@hp.com>,
        Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>
Subject: Re: [RFC 0/3] hugetlbfs: optionally reserve all fs pages at mount
 time
Message-Id: <20150302151009.2ae58f4430f9f34b81533821@linux-foundation.org>
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References: <1425077893-18366-1-git-send-email-mike.kravetz@oracle.com>
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On Fri, 27 Feb 2015 14:58:08 -0800 Mike Kravetz <mike.kravetz@oracle.com> wrote:

> hugetlbfs allocates huge pages from the global pool as needed.  Even if
> the global pool contains a sufficient number pages for the filesystem
> size at mount time, those global pages could be grabbed for some other
> use.  As a result, filesystem huge page allocations may fail due to lack
> of pages.

Well OK, but why is this a sufficiently serious problem to justify
kernel changes?  Please provide enough info for others to be able
to understand the value of the change.