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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2377BC433F5 for ; Fri, 30 Sep 2022 11:02:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 870086B0072; Fri, 30 Sep 2022 07:02:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 81FB56B0073; Fri, 30 Sep 2022 07:02:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6E7558D0001; Fri, 30 Sep 2022 07:02:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 5B9D36B0072 for ; Fri, 30 Sep 2022 07:02:47 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 23CCC1A0636 for ; Fri, 30 Sep 2022 11:02:47 +0000 (UTC) X-FDA: 79968463974.03.80E0878 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.85.151]) by imf27.hostedemail.com (Postfix) with ESMTP id C470A40013 for ; Fri, 30 Sep 2022 11:02:44 +0000 (UTC) Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-304-1kEuWYt-Pb-bGG9NzbX_dA-1; Fri, 30 Sep 2022 12:02:41 +0100 X-MC-Unique: 1kEuWYt-Pb-bGG9NzbX_dA-1 Received: from AcuMS.Aculab.com (10.202.163.6) by AcuMS.aculab.com (10.202.163.6) with Microsoft SMTP Server (TLS) id 15.0.1497.38; Fri, 30 Sep 2022 12:02:38 +0100 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.040; Fri, 30 Sep 2022 12:02:38 +0100 From: David Laight To: 'Hugh Dickins' , Vlastimil Babka CC: Joel Fernandes , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Matthew Wilcox , Andrew Morton , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" Subject: RE: amusing SLUB compaction bug when CC_OPTIMIZE_FOR_SIZE Thread-Topic: amusing SLUB compaction bug when CC_OPTIMIZE_FOR_SIZE Thread-Index: AQHY1LmyNvo5HN+EEECxPXiP8YKQXa33zoaA Date: Fri, 30 Sep 2022 11:02:38 +0000 Message-ID: References: <35502bdd-1a78-dea1-6ac3-6ff1bcc073fa@suse.cz> <16fe443a-dabe-aa46-6bc7-dad03f29e0dc@google.com> In-Reply-To: <16fe443a-dabe-aa46-6bc7-dad03f29e0dc@google.com> Accept-Language: en-GB, 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 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1664535766; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XrU1diai/I48lJ4xPa40ltDny6VDcga2bsSaVmLpfQY=; b=Mwd/s1l8YOd2E/qBvY86D0ixSh/cUbl0k6kEzp3Ev2o0R92B5QZskVk6HbzKRXUqCu0C4r 5rWkLZkJw2zuxg7JApUHQ0cYRHfuJ9tlYIxQuBYM6vWKna4BYgkM00F8hPCRjRFLbIpQtc 5pq3cl+gH3n5ZH9CToJWj9gQRnXYY1A= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=none; spf=pass (imf27.hostedemail.com: domain of david.laight@aculab.com designates 185.58.85.151 as permitted sender) smtp.mailfrom=david.laight@aculab.com; dmarc=pass (policy=none) header.from=aculab.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1664535766; a=rsa-sha256; cv=none; b=ujdeyVRnYL5B75cndLl5vkNPDN6u6ADTwu5fQyAegDcIEYbP9dsH7fabLZzbY8JC4COGgi tPEkkF4cTKA7U3Cqd+YsRZl+xK7kJ4c8OgbHEtX4zfshuTV8pfO7Dpufqr+w81pCn8BuUF E1oRqUQzKdY1sL9nxHLzE5we1kh0CPM= X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: C470A40013 Authentication-Results: imf27.hostedemail.com; dkim=none; spf=pass (imf27.hostedemail.com: domain of david.laight@aculab.com designates 185.58.85.151 as permitted sender) smtp.mailfrom=david.laight@aculab.com; dmarc=pass (policy=none) header.from=aculab.com X-Stat-Signature: oyph59n5ndh8dw8odd7p47iwp8t66yk3 X-HE-Tag: 1664535764-660358 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000189, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: > > > Regarding "conflicting" alignment requests: yes, I agree with you, > > > it would have to be a toolchain bug if when asked to align 2 and to > > > align 4, it chose not to align 4. See https://godbolt.org/z/3nGsTaf5e the align() directive takes precedence. Here you only want to ensure the alignment is at least 4. =09David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1= PT, UK Registration No: 1397386 (Wales)