Message-ID: <1435873760.10531.11.camel@freescale.com>
Subject: Re: [RFC PATCH 6/6] powerpc/kvm: change the condition of
 identifying hugetlb vm
From: Scott Wood <scottwood@freescale.com>
To: Wenwei Tao <wenweitaowenwei@gmail.com>
CC: <izik.eidus@ravellosystems.com>, <aarcange@redhat.com>,
        <chrisw@sous-sol.org>, <hughd@google.com>, <tglx@linutronix.de>,
        <mingo@redhat.com>, <hpa@zytor.com>, <x86@kernel.org>,
        <viro@zeniv.linux.org.uk>, <linux-mm@kvack.org>,
        <linux-fsdevel@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linuxppc-dev@lists.ozlabs.org>, <kvm@vger.kernel.org>,
        <kvm-ppc@vger.kernel.org>
Date: Thu, 2 Jul 2015 16:49:20 -0500
In-Reply-To: <1433917639-31699-7-git-send-email-wenweitaowenwei@gmail.com>
References: <1433917639-31699-1-git-send-email-wenweitaowenwei@gmail.com>
	 <1433917639-31699-7-git-send-email-wenweitaowenwei@gmail.com>
Content-Type: text/plain; charset="UTF-8"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Jul 2015 21:49:39.8920 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN3PR03MB1477
X-Microsoft-Exchange-Diagnostics: 1;BN3PR03MB1429;2:qJNG9GnShkjwreg7IFmzHcGKOjleZOrWdJrVRlHMwANB6x6HMGcceXpSsUM6a/4D;3:rEDwHq8D9vQQOEAqFSQcWkGweDVhA/whToeEX+VKnFtS7Z1o0hLEitMZ3RtNk9eA1Gt8zuVh/abpSve+QeynFik/FaUlkQvHUXyH+SHj46mntRK6/m5P8trJ8azfrN0ci4bjFSWTdvL0Om6H3APvqw==;25:+nRByqkuuCFudFjowmaVF4kfrjnHUJtxWSjSENNAXV4gJ2snd+wo1WzMV2uxqI+Z7JWtDPF1J8PUOWy1vpS04a2JFSvId9/Eh3nJnsfpTZ+HdpHQUKVZvF78DvEbdE4I55pTiRa37BT3NgLJ59YeAScS25aTS9IL/7xH73G+zFZF5lgEKPN6GLFa4v7p/rT2pZ+kwf5MydZbpTnVMBoNSZJCrnWFwpzXB77kmctxphmeswmNxp/H8neKhvxrYz9X;23:qSbccSBt0xkgC3ICSTY+cGh8VjGK/UBiLCWku/iUlh5GY7UlN9xjVAQzhPAyPAo/4j1KmZVowv/qrMeQT4kwQK9Lf+nfp3bHIkhDUqC6+vDWeakhK5aSHe9vMJbJRPxwMUQ1FS9im28TTxvRETyb9QZHyDTJeOaOk7AcWzp62fmV/iLHacRwgib5Ljn26INzFWFXhnghFUId2jwgeIBoE6Gm/xqDpfV7q2Ch3plleqv52e2SFb/tmIbvMSD/HVT8
X-OriginatorOrg: freescale.com
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 727
Lines: 20

On Wed, 2015-06-10 at 14:27 +0800, Wenwei Tao wrote:
> Hugetlb VMAs are not mergeable, that means a VMA couldn't have VM_HUGETLB 
> and
> VM_MERGEABLE been set in the same time. So we use VM_HUGETLB to indicate new
> mergeable VMAs. Because of that a VMA which has VM_HUGETLB been set is a 
> hugetlb
> VMA only if it doesn't have VM_MERGEABLE been set in the same time.

Eww.

If you must overload such bit combinations, please hide it behind a 
vm_is_hugetlb() function.

-Scott

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/