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 93469C25B06 for ; Mon, 15 Aug 2022 01:59:35 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2A0468D0003; Sun, 14 Aug 2022 21:59:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 24FBA8D0002; Sun, 14 Aug 2022 21:59:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 117E88D0003; Sun, 14 Aug 2022 21:59:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 02F978D0002 for ; Sun, 14 Aug 2022 21:59:35 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id CB599120CF3 for ; Mon, 15 Aug 2022 01:59:34 +0000 (UTC) X-FDA: 79800170268.22.967315A Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by imf15.hostedemail.com (Postfix) with ESMTP id 29DF0A01C0 for ; Mon, 15 Aug 2022 01:59:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1660528774; x=1692064774; h=from:to:cc:subject:references:date:in-reply-to: message-id:mime-version; bh=kA7lDKgziz+W9ciW3E//tMKB+dBOyRW8yX0jMyo2XGo=; b=UvEu6L323nNiIrt7wOM56TKJdlG90zojMU5h22uKmOhx0q36bAeMBjMi qBGiG3wpvIgcINISF6/lPqbPfIaIKH2fHmhsbuKjBDaagm+RSCqpkjryA DgsU47Z56XFr5RWRORnUxcf+UrTXg2ySe64xaHZ+WDlLN/yxB9oSkfmAf b+mPa9QjHU4VJTOdj24OmNk+sP5Wmpyt/Ds5dP+d2KlQGyRvfu13bh10z zmgt8j58+gSXfX/WWfgv74fI8vMgtGFADKBqfWjm9da5BghdiYKAvA7dT rfG7coF5ee5rO22XsbEe4lN7r/6QbXQoXJ79IAJxs7U4kgCW/WRbDZPc5 g==; X-IronPort-AV: E=McAfee;i="6400,9594,10439"; a="353613396" X-IronPort-AV: E=Sophos;i="5.93,237,1654585200"; d="scan'208";a="353613396" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Aug 2022 18:59:32 -0700 X-IronPort-AV: E=Sophos;i="5.93,237,1654585200"; d="scan'208";a="582716835" Received: from yhuang6-desk2.sh.intel.com (HELO yhuang6-desk2.ccr.corp.intel.com) ([10.238.208.55]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Aug 2022 18:59:30 -0700 From: "Huang, Ying" To: Haiyue Wang Cc: , , , , , , , 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> Date: Mon, 15 Aug 2022 09:59:27 +0800 In-Reply-To: <20220815010349.432313-2-haiyue.wang@intel.com> (Haiyue Wang's message of "Mon, 15 Aug 2022 09:03:48 +0800") Message-ID: <878rnqe074.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 ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=UvEu6L32; dmarc=pass (policy=none) header.from=intel.com; spf=pass (imf15.hostedemail.com: domain of ying.huang@intel.com designates 134.134.136.31 as permitted sender) smtp.mailfrom=ying.huang@intel.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660528774; a=rsa-sha256; cv=none; b=cHq+ObdpIfBVMsUNYgsTVUgtM7huo72B8l8iKOs0/fhnZRNK4aGf4gH/TiVyYvBvP+3zp1 HvaC3lzzXNG8ouTauvogEkRggiXXATVdLi96AiuHmUi37f8hAmNqv93dgaKMedVa4P5XCO BUTrJQJZN3ca2DrcCvCREE+5wD9kYo4= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660528774; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=gr9WCBJ2fkX5R+ZzKKFumU9ZaQ3KGy7rFyCfh8SmKzg=; b=Oe/sakhpefiWDFd3FIbQ9H9VCu3m1X4h7gd+Pd6uyLbqsiPCKTvJbqUw3bohdeYmKTz7Xd ssN+HddNBHr0xX4vikFkYPE9Q4ICDFTRFTs+6qPs66H/oxFY+v0f3MYBeHacP3gzjOXD03 aU/+g1sRQNII9/OGLrt09riF5nZ3JvA= X-Rspam-User: Authentication-Results: imf15.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=UvEu6L32; dmarc=pass (policy=none) header.from=intel.com; spf=pass (imf15.hostedemail.com: domain of ying.huang@intel.com designates 134.134.136.31 as permitted sender) smtp.mailfrom=ying.huang@intel.com X-Stat-Signature: gq4xhpytgkhit73kur49y5gmus9kkuam X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 29DF0A01C0 X-HE-Tag: 1660528773-9003 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: Haiyue Wang writes: > Not all huge page APIs support FOLL_GET option, so the __NR_move_pages move_pages() is a syscall, so you can just call it move_pages(), or move_pages() syscall. > will fail to get the page node information for huge page. ~~~~~~~~~ some huge pages? > This is an temporary solution to mitigate the racing fix. Why is it "racing fix"? This isn't a race condition fix. 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]