From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0C01FC433DF for ; Fri, 17 Jul 2020 08:33:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 08E182071A for ; Fri, 17 Jul 2020 08:33:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 08E182071A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=ACULAB.COM Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A15FB8D001D; Fri, 17 Jul 2020 04:33:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9C3C28D0001; Fri, 17 Jul 2020 04:33:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8B37F8D001D; Fri, 17 Jul 2020 04:33:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 754318D0001 for ; Fri, 17 Jul 2020 04:33:24 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 3655118F69 for ; Fri, 17 Jul 2020 08:33:24 +0000 (UTC) X-FDA: 77046903528.21.fang99_200752426f09 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin21.hostedemail.com (Postfix) with ESMTP id 6DE88180938E0 for ; Fri, 17 Jul 2020 08:32:20 +0000 (UTC) X-HE-Tag: fang99_200752426f09 X-Filterd-Recvd-Size: 3784 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [207.82.80.151]) by imf47.hostedemail.com (Postfix) with ESMTP for ; Fri, 17 Jul 2020 08:32:14 +0000 (UTC) Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-30-vOfOUf7XOJW9yv-pErlP7A-1; Fri, 17 Jul 2020 09:32:08 +0100 X-MC-Unique: vOfOUf7XOJW9yv-pErlP7A-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) by AcuMS.aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Fri, 17 Jul 2020 09:32:07 +0100 Received: from AcuMS.Aculab.com ([fe80::43c:695e:880f:8750]) by AcuMS.aculab.com ([fe80::43c:695e:880f:8750%12]) with mapi id 15.00.1347.000; Fri, 17 Jul 2020 09:32:07 +0100 From: David Laight To: "'js1304@gmail.com'" , Andrew Morton CC: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "kernel-team@lge.com" , Vlastimil Babka , Christoph Hellwig , Roman Gushchin , Mike Kravetz , "Naoya Horiguchi" , Michal Hocko , "Aneesh Kumar K . V" , Joonsoo Kim , "stable@vger.kernel.org" Subject: RE: [PATCH 1/4] mm/page_alloc: fix non cma alloc context Thread-Topic: [PATCH 1/4] mm/page_alloc: fix non cma alloc context Thread-Index: AQHWWmWbQrqMs3IygU6Uq8saGSVLGakLcr1w Date: Fri, 17 Jul 2020 08:32:07 +0000 Message-ID: References: <1594789529-6206-1-git-send-email-iamjoonsoo.kim@lge.com> In-Reply-To: <1594789529-6206-1-git-send-email-iamjoonsoo.kim@lge.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 6DE88180938E0 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: js1304@gmail.com > Sent: 15 July 2020 06:05 > From: Joonsoo Kim >=20 > Currently, preventing cma area in page allocation is implemented by using > current_gfp_context(). However, there are two problems of this > implementation. ... > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 6416d08..cd53894 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c ... > @@ -3693,6 +3691,16 @@ alloc_flags_nofragment(struct zone *zone, gfp_t gf= p_mask) > =09return alloc_flags; > } >=20 > +static inline void current_alloc_flags(gfp_t gfp_mask, > +=09=09=09=09unsigned int *alloc_flags) > +{ > +=09unsigned int pflags =3D READ_ONCE(current->flags); > + > +=09if (!(pflags & PF_MEMALLOC_NOCMA) && > +=09=09gfp_migratetype(gfp_mask) =3D=3D MIGRATE_MOVABLE) > +=09=09*alloc_flags |=3D ALLOC_CMA; > +} > + I'd guess this would be easier to understand and probably generate better code if renamed and used as: =09alloc_flags |=3D can_alloc_cma(gpf_mask); Given it is a 'static inline' the compiler might end up generating the same code. If you needed to clear a flag doing: =09alloc_flags =3D current_alloc_flags(gpf_mask, alloc_flags); is much better for non-inlined function. =09David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1= PT, UK Registration No: 1397386 (Wales)