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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 864BDC25B06 for ; Mon, 15 Aug 2022 02:51:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232360AbiHOCvp (ORCPT ); Sun, 14 Aug 2022 22:51:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229619AbiHOCvo (ORCPT ); Sun, 14 Aug 2022 22:51:44 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CDD1F13DE7 for ; Sun, 14 Aug 2022 19:51:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1660531903; x=1692067903; h=from:to:cc:subject:references:date:in-reply-to: message-id:mime-version; bh=+PBNMqIeqDhFYEnVesPZtIzro2EO9NNYkXRv9MxnHf0=; b=b/KZtne5eIlvVZmJ903A+RQjfOLedqeuecjNjiGn2dpYoDPJr4vES1nu mkxJGZJ90sW0CUeg5LolSIb1uIoFyB9nJ/y0UgpJmkvJUGQUbzAZk1vOs ulUX5DavaxCvk61NDkGanAK3nvK64rUkiSP3c3djz0Yqg8lcQFWINWeB3 6Z0AZuRbPVwzxuRNjULapSreuyrNV2n7YXalhHtf6qXx9WlbSCghM1IY/ 7/qVOFrTlTd6FxiJnpT22tgcBRT4aC7CeGjdEBgr6hxTywN5pUZmVaWnN K5vK4gP2bS8PcIEZOnRnGPpzatDA1C0x+wJQqkrE782gy7VoJ39CLakis A==; X-IronPort-AV: E=McAfee;i="6400,9594,10439"; a="293147980" X-IronPort-AV: E=Sophos;i="5.93,237,1654585200"; d="scan'208";a="293147980" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Aug 2022 19:51:43 -0700 X-IronPort-AV: E=Sophos;i="5.93,237,1654585200"; d="scan'208";a="635326866" Received: from yhuang6-desk2.sh.intel.com (HELO yhuang6-desk2.ccr.corp.intel.com) ([10.238.208.55]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Aug 2022 19:51:41 -0700 From: "Huang, Ying" To: "Wang, Haiyue" Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , "david@redhat.com" , "linmiaohe@huawei.com" , "songmuchun@bytedance.com" , "naoya.horiguchi@linux.dev" , "alex.sierra@amd.com" Subject: Re: [PATCH v3 1/2] mm: migration: fix the FOLL_GET failure on following huge page References: <20220812084921.409142-1-haiyue.wang@intel.com> <20220815010349.432313-1-haiyue.wang@intel.com> <20220815010349.432313-2-haiyue.wang@intel.com> <878rnqe074.fsf@yhuang6-desk2.ccr.corp.intel.com> Date: Mon, 15 Aug 2022 10:51:37 +0800 In-Reply-To: (Haiyue Wang's message of "Mon, 15 Aug 2022 10:15:41 +0800") Message-ID: <87o7wmcj7q.fsf@yhuang6-desk2.ccr.corp.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=ascii Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "Wang, Haiyue" writes: >> -----Original Message----- >> From: Wang, Haiyue >> Sent: Monday, August 15, 2022 10:11 >> To: Huang, Ying >> Cc: linux-mm@kvack.org; linux-kernel@vger.kernel.org; akpm@linux-foundation.org; david@redhat.com; >> linmiaohe@huawei.com; songmuchun@bytedance.com; naoya.horiguchi@linux.dev; alex.sierra@amd.com >> Subject: RE: [PATCH v3 1/2] mm: migration: fix the FOLL_GET failure on following huge page >> >> > -----Original Message----- >> > From: Huang, Ying >> > Sent: Monday, August 15, 2022 09:59 >> > To: Wang, Haiyue >> > Cc: linux-mm@kvack.org; linux-kernel@vger.kernel.org; akpm@linux-foundation.org; david@redhat.com; >> > linmiaohe@huawei.com; songmuchun@bytedance.com; naoya.horiguchi@linux.dev; alex.sierra@amd.com >> > Subject: Re: [PATCH v3 1/2] mm: migration: fix the FOLL_GET failure on following huge page >> > >> > Haiyue Wang writes: >> > > > >> > >> > > This is an temporary solution to mitigate the racing fix. >> > >> > Why is it "racing fix"? This isn't a race condition fix. >> >> The 'Fixes' commit is about race condition fix. >> >> How about " his is an temporary solution to mitigate the side effect >> Of the race condition fix" > > Try to add more words to make things clean: > > "This is an temporary solution to mitigate the side effect of the race > condition fix by calling follow_page() with FOLL_GET set." Looks good to me. Thanks! Best Regards, Huang, Ying >> >> > >> > Best Regards, >> > Huang, Ying >> > >> > > After supporting follow huge page by FOLL_GET is done, this fix can be >> > > reverted safely. >> > > >> > > Fixes: 4cd614841c06 ("mm: migration: fix possible do_pages_stat_array racing with memory offline") >> > > Signed-off-by: Haiyue Wang >> > >> > [snip]