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=-1.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS,URIBL_BLOCKED autolearn=ham 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 89102C0044C for ; Fri, 2 Nov 2018 00:43:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 33F4820862 for ; Fri, 2 Nov 2018 00:43:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="KAElC0/R" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 33F4820862 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726370AbeKBJsa (ORCPT ); Fri, 2 Nov 2018 05:48:30 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:45794 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726016AbeKBJsa (ORCPT ); Fri, 2 Nov 2018 05:48:30 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id wA20dfMw186271; Fri, 2 Nov 2018 00:41:41 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=content-type : mime-version : subject : from : in-reply-to : date : cc : content-transfer-encoding : message-id : references : to; s=corp-2018-07-02; bh=I2BjZzx4L+Yjwo7CrwFlb+XzIAoWGoxUImIjHRGixEQ=; b=KAElC0/RZOHcVT6TlLrytNOEfponspJugmyYZvR/jSDN3+QYeVxe2uZcOYYPXqZ1J13a ZCt/LnrHhP84jfNb1EHiGhItQH7e7Te+ing/y25Q0f5hzNT1/UbqFkNMSrSvdyqpN5v7 T3l4LdhaQcr+ovtySUdU/yai4kAySrNQgTG55wG0avOXwMsPAEwiS0VPbl3li2js/5Zu mHCfhEOwhgGGrNa/G1MYopI6cyQkpICGzPlseITKbAWP3afwzCpvBLUBj514/PxcyuB5 9OS/D92zmORlioRKNqA2WA9uY87lty4T/P+1IXSnQACAgt7GdY9IwaVk0Y7QfA+PAEeL Mw== Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by aserp2120.oracle.com with ESMTP id 2ncfyqbvgf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 02 Nov 2018 00:41:41 +0000 Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id wA20faPQ024811 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 2 Nov 2018 00:41:36 GMT Received: from abhmp0003.oracle.com (abhmp0003.oracle.com [141.146.116.9]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id wA20fYQ3006490; Fri, 2 Nov 2018 00:41:35 GMT Received: from [192.168.0.110] (/73.243.10.6) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 01 Nov 2018 17:41:34 -0700 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 12.2 \(3445.102.3\)) Subject: Re: [PATCH v4] mm/page_owner: clamp read count to PAGE_SIZE From: William Kucharski In-Reply-To: <20181101144723.3ddc1fa1ab7f81184bc2fdb8@linux-foundation.org> Date: Thu, 1 Nov 2018 18:41:33 -0600 Cc: miles.chen@mediatek.com, Michal Hocko , Joe Perches , Matthew Wilcox , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, wsd_upstream@mediatek.com, Michal Hocko Content-Transfer-Encoding: quoted-printable Message-Id: References: <1541091607-27402-1-git-send-email-miles.chen@mediatek.com> <20181101144723.3ddc1fa1ab7f81184bc2fdb8@linux-foundation.org> To: Andrew Morton X-Mailer: Apple Mail (2.3445.102.3) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9064 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=917 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1811020004 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Nov 1, 2018, at 3:47 PM, Andrew Morton = wrote: >=20 > - count =3D count > PAGE_SIZE ? PAGE_SIZE : count; > + count =3D min_t(size_t, count, PAGE_SIZE); > kbuf =3D kmalloc(count, GFP_KERNEL); > if (!kbuf) > return -ENOMEM; Is the use of min_t vs. the C conditional mostly to be more = self-documenting? The compiler-generated assembly between the two versions seems mostly a = wash. William Kucharski=