From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755482Ab2LLWE3 (ORCPT ); Wed, 12 Dec 2012 17:04:29 -0500 Received: from mga01.intel.com ([192.55.52.88]:36305 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755407Ab2LLWE2 (ORCPT ); Wed, 12 Dec 2012 17:04:28 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,269,1355126400"; d="asc'?scan'208";a="261342900" Date: Thu, 13 Dec 2012 00:05:05 +0200 From: "Kirill A. Shutemov" To: "H. Peter Anvin" Cc: Andrew Morton , David Rientjes , Andrea Arcangeli , linux-mm@kvack.org, Andi Kleen , linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: Re: [PATCH v5 09/11] thp: lazy huge zero page allocation Message-ID: <20121212220505.GA24391@otc-wbsnb-06> References: <1352300463-12627-1-git-send-email-kirill.shutemov@linux.intel.com> <1352300463-12627-10-git-send-email-kirill.shutemov@linux.intel.com> <20121115094155.GG9676@otc-wbsnb-06> <20121212133051.6dad3722.akpm@linux-foundation.org> <50C8FB94.6050209@linux.intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="SUOF0GtieIMvvwua" Content-Disposition: inline In-Reply-To: <50C8FB94.6050209@linux.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --SUOF0GtieIMvvwua Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Dec 12, 2012 at 01:48:04PM -0800, H. Peter Anvin wrote: > On 12/12/2012 01:30 PM, Andrew Morton wrote: > >> > >> I can rewrite the check to static_key if you want. Would it be better? > >=20 > > The new test-n-branch only happens on the first read fault against a > > thp huge page, yes? In which case it's a quite infrequent event and I > > suspect this isn't worth bothering about. > >=20 >=20 > Not to mention that flipping the static key is *incredibly* expensive. I'm fine with current code. --=20 Kirill A. Shutemov --SUOF0GtieIMvvwua Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJQyP+RAAoJEAd+omnVudOMa90QALBZOAUjaliAIrj0hqiEd5Sk RmyTE20WVt2iJE9uqwIoreb2gjzKkzRHQOydkuSgBZNt9VatO0IA+OEkNabpj9fZ /lp+H183t36QIuLGnrVeRVo5T70/2fsUak7BfrErl6km7GK6GckdzpWWmDNww+Mj qto5iVpDl1I/a74kOtw07kXo4N2omLJGwNmBXjj4JBZTG+oSqftJ25utwt6FvdKR KxdSjNqP8BZjFG9bCpYzglQsJemoQ8TS8MHmZbM+C9EbZf4vC4RCPF8Bh1MUgSfB wfRoyYPKD10hk2vUyMcz3fP/GwnBsIFdBc2Q1egZDOHzFMhESB8wRjdQjX2lzUBP KVgumRkA4gqFBqX3YGComAqO4NC29bc4KXua2273KOD6KGXaV1Ub3tncNQwnbXFT yGHhj21JjGoOPbaujA68F6aeMhUYrcwaZhQKIO+m82s0ugkYfO/HXjx6gMGOQW2L TY1km/mEb0D34pq/L8de4fZPBt30moP4IQ30JdfenXMPTuvUwGcD6HtpimKtasWb 6LQvIeXZp4SZdkJ+iOOAJCTPrj39ghBNctSvno28pOSJWONx4gRy1YAbcq74UPJw sxH3JgfApoQ68TrDCXHCnpEoIZurpiEJF7UVYia9Xj7BkVmUWqBdT2nJe4q6WgGi zIE3gnh9sr2Dcg299Oc1 =8qpu -----END PGP SIGNATURE----- --SUOF0GtieIMvvwua--