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From: Mel Gorman <mgorman@techsingularity.net>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: akpm@linux-foundation.org, Rik van Riel <riel@surriel.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/autonuma: don't use set_pte_at when updating protnone ptes
Date: Mon, 6 Feb 2017 22:26:42 +0000	[thread overview]
Message-ID: <20170206222642.u2e5ip4h2udaehr4@techsingularity.net> (raw)
In-Reply-To: <1486400776-28114-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

On Mon, Feb 06, 2017 at 10:36:16PM +0530, Aneesh Kumar K.V wrote:
> Architectures like ppc64, use privilege access bit to mark pte non accessible.
> This implies that kernel can do a copy_to_user to an address marked for numa fault.
> This also implies that there can be a parallel hardware update for the pte.
> set_pte_at cannot be used in such scenarios. Hence switch the pte
> update to use ptep_get_and_clear and set_pte_at combination.
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

Yeah, ok. The main thing is that it still avoids doing an unnecessary TLB
flush so

Acked-by: Mel Gorman <mgorman@techsingularity.net>

-- 
Mel Gorman
SUSE Labs

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  parent reply	other threads:[~2017-02-06 22:26 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-06 17:06 [PATCH] mm/autonuma: don't use set_pte_at when updating protnone ptes Aneesh Kumar K.V
2017-02-06 18:46 ` Rik van Riel
2017-02-06 22:26 ` Mel Gorman [this message]
2017-02-07  8:09 ` John Hubbard
2017-02-14 14:11 ` Aneesh Kumar K.V
2017-02-15  0:05   ` Andrew Morton

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