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 0746EC19F2D for ; Sat, 13 Aug 2022 23:28:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 728206B0073; Sat, 13 Aug 2022 19:28:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6D7B76B0074; Sat, 13 Aug 2022 19:28:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 59F998E0001; Sat, 13 Aug 2022 19:28:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 4BEC96B0073 for ; Sat, 13 Aug 2022 19:28:42 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 1C020C07F4 for ; Sat, 13 Aug 2022 23:28:42 +0000 (UTC) X-FDA: 79796161284.22.6135E8E Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf30.hostedemail.com (Postfix) with ESMTP id B1FCB80192 for ; Sat, 13 Aug 2022 23:28:41 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id CDFA360CFB; Sat, 13 Aug 2022 23:28:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DC8A8C433D6; Sat, 13 Aug 2022 23:28:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1660433320; bh=/nd0iG9fLC7CgVX6HvULDZV4QNZrX4MQtqqRHeB/XCY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Y8HUp8Mxi0d6URADjUtO3p26TwUAoTrvTRrKMv0VLOEqO9dI7WQmvMImQXnU4wpTh 8UnMSrANJHAeQDNJvbv9rImyRCsEhBQMRMJx2mw3qQbSq9mmHaAn/gEYRdOkWAtOZK Mlq8Gv6WSLhwz1ZPAQJzXpfmVJFvmKuoTQ4nzCCM= Date: Sat, 13 Aug 2022 16:28:37 -0700 From: Andrew Morton To: Haiyue Wang Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, david@redhat.com, linmiaohe@huawei.com, ying.huang@intel.com, songmuchun@bytedance.com, naoya.horiguchi@linux.dev Subject: Re: [PATCH v1] mm: migration: fix the FOLL_GET failure on following huge page Message-Id: <20220813162837.cc20e208e7a9d65fd2e7dc14@linux-foundation.org> In-Reply-To: <20220812084921.409142-1-haiyue.wang@intel.com> References: <20220812084921.409142-1-haiyue.wang@intel.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=Y8HUp8Mx; spf=pass (imf30.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660433321; a=rsa-sha256; cv=none; b=dgVEmB0OBkODbOcN7h+/bDCBUBEoimSG5hItea9/k6nLo4fYUyx+vPw0jjdyFswHjKRvGn +Iin5vCD9Gemv0rNMUshWOVas0oLovtse/xT7i0Kegb/EKtzVPmLLXmMkTe63snIbU5Mux nGnWyXhgt03yQ0A1OhL+OG4cvhEANs8= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660433321; 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:dkim-signature; bh=k2HXj1ftKqQzS7OWACfiV9g8z1v8ZgNeYGZxqozA+Pc=; b=BxqpSu33uRQpFKmBsObTm8BgkqRkBd/kMZNjyoRSsMmY4MxC69WxtiAPgeRPep/AJAJ11G NveYx6j2lvj9X5rgoYZM/pswivEXAQWroh/40KSzPJ5Ulp0sU5AlpG+h5/L/DcLrw5J3Rc VhTGobBsbqEuqLrgFz8rIY3kW1rJwAE= Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=Y8HUp8Mx; spf=pass (imf30.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: B1FCB80192 X-Stat-Signature: 9au59q4u3j7ukxcqp7oodnjf5iajgwu8 X-Rspam-User: X-HE-Tag: 1660433321-622833 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: On Fri, 12 Aug 2022 16:49:21 +0800 Haiyue Wang wrote: > Not all huge page APIs support FOLL_GET option, so the __NR_move_pages > will fail to get the page node information for huge page. Which ones need fixing? What are the user-visible runtime effects of this bug? Is a -stable backport warranted? > This is an temporary solution to mitigate the racing fix. > > After supporting follow huge page by FOLL_GET is done, this fix can be > reverted safely. >