From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 843E16B0033 for ; Tue, 7 Feb 2017 10:07:12 -0500 (EST) Received: by mail-pf0-f197.google.com with SMTP id 201so152941886pfw.5 for ; Tue, 07 Feb 2017 07:07:12 -0800 (PST) Received: from mail-pg0-x244.google.com (mail-pg0-x244.google.com. [2607:f8b0:400e:c05::244]) by mx.google.com with ESMTPS id d20si4287034plj.252.2017.02.07.07.07.11 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 07 Feb 2017 07:07:11 -0800 (PST) Received: by mail-pg0-x244.google.com with SMTP id 204so12356887pge.2 for ; Tue, 07 Feb 2017 07:07:11 -0800 (PST) Date: Tue, 7 Feb 2017 23:07:08 +0800 From: Wei Yang Subject: Re: [PATCH] mm/page_alloc: return 0 in case this node has no page within the zone Message-ID: <20170207150708.GA31837@WeideMBP.lan> Reply-To: Wei Yang References: <20170206154314.15705-1-richard.weiyang@gmail.com> <20170206152932.19e7947df487b96b8912e524@linux-foundation.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="opJtzjQTFsWo+cga" Content-Disposition: inline In-Reply-To: <20170206152932.19e7947df487b96b8912e524@linux-foundation.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Wei Yang , vbabka@suse.cz, mgorman@techsingularity.net, mhocko@suse.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org --opJtzjQTFsWo+cga Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Feb 06, 2017 at 03:29:32PM -0800, Andrew Morton wrote: >On Mon, 6 Feb 2017 23:43:14 +0800 Wei Yang wr= ote: > >> The whole memory space is divided into several zones and nodes may have = no >> page in some zones. In this case, the __absent_pages_in_range() would >> return 0, since the range it is searching for is an empty range. >>=20 >> Also this happens more often to those nodes with higher memory range when >> there are more nodes, which is a trend for future architectures. >>=20 >> This patch checks the zone range after clamp and adjustment, return 0 if >> the range is an empty range. > >What are the user-visible runtime effects of this change? Hmm, for users they may not "see" the effect, while it will save some time = in case there is no overlap between the zone and node. --=20 Wei Yang Help you, Help me --opJtzjQTFsWo+cga Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJYmeKcAAoJEKcLNpZP5cTdlecP/jig142NOblvsOOeW1QhjmuY vajC3YHaGc1Vyj+otaaYliiPuFHzk1Sh7Tts/RZ08Qnzw5FfT47aAnxuowMt3sLD r5TxYvEWSJOJTMO0MrlupTwe1nHpLALXOGYm6kHNdvkoX/vyK89ATjLCzVplkCiQ p/jSvwdtkO9He1vCJjBJv+YgUxUeWtr+7EcI5HnM7oyc+EPpquczta0drLS5VLAA H8bSJamP9QDqShpVME8U6hTplL8RfgRM/CpAp7ZTImvVIfv2TzpqNM/m8cHY5XQI tsF2CMuZgLS8Tr0nXw0MC7il9djbDKAlmT9EDo0zU4XR8dhINiDzrFXR4eja8rlo jFi6Ac8ow3jmH+Oz1x8j1Tc1bZEBNg2y/17B+rD+lXyA+bPdbson68bgi7VntBMB Ro9rKgLoyOShT44QkJsZbtgq7ea8h1pzp3MYF1KgeRG600DaHE6wZFL+FJXxC4Wv d8zAImwoMUhMY//EQD6DfuDmTPJrKvB4s4VeiiA6y1U/8LYPWS1/V0MH/mMrUPpk LiZGe3MvUFGoUNQttAAyE6pfDNf1vJWZVBU+ltHg3JizR0/u+5vZiuK7paSu7B+e 5Jx2JS7YCi/uRUdaJVTLV1wfQ9xqxDZxUZ3l6GJAoDsgtpdym4pdF+biFcia+/AJ tHTw7tbBT3nFKy88EDkk =j7et -----END PGP SIGNATURE----- --opJtzjQTFsWo+cga-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org