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Date: Fri, 24 Apr 2015 16:16:52 +0100
From: Mel Gorman <mgorman@suse.de>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Linux-MM <linux-mm@kvack.org>, Rik van Riel <riel@redhat.com>,
        Hugh Dickins <hughd@google.com>, Minchan Kim <minchan@kernel.org>,
        Dave Hansen <dave.hansen@intel.com>, Andi Kleen <andi@firstfloor.org>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH 0/6] TLB flush multiple pages with a single IPI v3
Message-ID: <20150424151652.GC2449@suse.de>
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 <553A573E.2000608@suse.cz>
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On Fri, Apr 24, 2015 at 04:46:22PM +0200, Vlastimil Babka wrote:
> On 04/21/2015 12:41 PM, Mel Gorman wrote:
> >Changelog since V2
> >o Ensure TLBs are flushed before pages are freed		(mel)
> 
> I admit not reading all the patches thoroughly, but doesn't this
> change of ordering mean that you no longer need the architectural
> guarantee discussed in patch 2?

No. If we unmap a page to write it to disk then we cannot allow a CPU to
write to the physical page being written through a cached entry.

-- 
Mel Gorman
SUSE Labs