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Date: Mon, 1 Apr 2013 16:35:38 -0700 (PDT)
From: David Rientjes <rientjes@google.com>
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To: Minchan Kim <minchan@kernel.org>
cc: Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, Mel Gorman <mgorman@suse.de>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Hugh Dickins <hughd@google.com>
Subject: Re: [PATCH] THP: Use explicit memory barrier
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On Mon, 1 Apr 2013, Minchan Kim wrote:

> __do_huge_pmd_anonymous_page depends on page_add_new_anon_rmap's
> spinlock for making sure that clear_huge_page write become visible
> after set set_pmd_at() write.
> 
> But lru_cache_add_lru uses pagevec so it could miss spinlock
> easily so above rule was broken so user may see inconsistent data.
> 
> This patch fixes it with using explict barrier rather than depending
> on lru spinlock.
> 

Is this the same issue that Andrea responded to in the "thp and memory 
barrier assumptions" thread at http://marc.info/?t=134333512700004 ?

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Date: Mon, 1 Apr 2013 16:35:38 -0700 (PDT)
From: David Rientjes <rientjes@google.com>
Subject: Re: [PATCH] THP: Use explicit memory barrier
In-Reply-To: <1364773535-26264-1-git-send-email-minchan@kernel.org>
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To: Minchan Kim <minchan@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Mel Gorman <mgorman@suse.de>, Andrea Arcangeli <aarcange@redhat.com>, Hugh Dickins <hughd@google.com>

On Mon, 1 Apr 2013, Minchan Kim wrote:

> __do_huge_pmd_anonymous_page depends on page_add_new_anon_rmap's
> spinlock for making sure that clear_huge_page write become visible
> after set set_pmd_at() write.
> 
> But lru_cache_add_lru uses pagevec so it could miss spinlock
> easily so above rule was broken so user may see inconsistent data.
> 
> This patch fixes it with using explict barrier rather than depending
> on lru spinlock.
> 

Is this the same issue that Andrea responded to in the "thp and memory 
barrier assumptions" thread at http://marc.info/?t=134333512700004 ?

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