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Date: Tue, 01 Jul 2014 14:00:32 -0700
From: Dave Hansen <dave.hansen@intel.com>
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To: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>, linux-mm@kvack.org
CC: Andrew Morton <akpm@linux-foundation.org>, Hugh Dickins <hughd@google.com>,
        "Kirill A. Shutemov" <kirill@shutemov.name>,
        Jerome Marchand <jmarchan@redhat.com>, linux-kernel@vger.kernel.org,
        Naoya Horiguchi <nao.horiguchi@gmail.com>,
        Jet Chen <jet.chen@intel.com>
Subject: Re: [PATCH v4 11/13] mempolicy: apply page table walker on queue_pages_range()
References: <1404234451-21695-1-git-send-email-n-horiguchi@ah.jp.nec.com> <1404234451-21695-12-git-send-email-n-horiguchi@ah.jp.nec.com>
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On 07/01/2014 10:07 AM, Naoya Horiguchi wrote:
> queue_pages_range() does page table walking in its own way now, but there
> is some code duplicate. This patch applies page table walker to reduce
> lines of code.
> 
> queue_pages_range() has to do some precheck to determine whether we really
> walk over the vma or just skip it. Now we have test_walk() callback in
> mm_walk for this purpose, so we can do this replacement cleanly.
> queue_pages_test_walk() depends on not only the current vma but also the
> previous one, so queue_pages->prev is introduced to remember it.

Hi Naoya,

The previous version of this patch caused a performance regression which
was reported to you:

	http://marc.info/?l=linux-kernel&m=140375975525069&w=2

Has that been dealt with in this version somehow?