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Date: Wed, 06 Nov 2013 08:34:27 -0800
From: Dave Hansen <dave@sr71.net>
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To: Hillf Danton <dhillf@gmail.com>
CC: LKML <linux-kernel@vger.kernel.org>, Linux-MM <linux-mm@kvack.org>,
        dave.jiang@intel.com, Mel Gorman <mgorman@suse.de>,
        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 2/2] mm: thp: give transparent hugepage code a separate
 copy_page
References: <20131028221618.4078637F@viggo.jf.intel.com>	<20131028221620.042323B3@viggo.jf.intel.com> <CAJd=RBAFgn=3GvEEdHDARpw_h+6SbYE_35D5QJX7C60cVd4tmA@mail.gmail.com>
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On 11/06/2013 05:46 AM, Hillf Danton wrote:
> On Tue, Oct 29, 2013 at 6:16 AM, Dave Hansen <dave@sr71.net> wrote:
>> +
>> +void copy_high_order_page(struct page *newpage,
>> +                         struct page *oldpage,
>> +                         int order)
>> +{
>> +       int i;
>> +
>> +       might_sleep();
>> +       for (i = 0; i < (1<<order); i++) {
>> +               cond_resched();
>> +               copy_highpage(newpage + i, oldpage + i);
>> +       }
>> +}
> 
> Can we make no  use of might_sleep here with cond_resched in loop?

I'm not sure what you're saying.

Are you pointing out that cond_resched() actually calls might_sleep() so
the might_sleep() is redundant?