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=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 10638C07E95 for ; Sat, 10 Jul 2021 08:11:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 791A0613B6 for ; Sat, 10 Jul 2021 08:11:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 791A0613B6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2A3C46B0073; Sat, 10 Jul 2021 04:11:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 27A576B0078; Sat, 10 Jul 2021 04:11:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 11BC86B007B; Sat, 10 Jul 2021 04:11:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0106.hostedemail.com [216.40.44.106]) by kanga.kvack.org (Postfix) with ESMTP id D57026B0073 for ; Sat, 10 Jul 2021 04:11:42 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 0EDB82CBD0 for ; Sat, 10 Jul 2021 08:11:42 +0000 (UTC) X-FDA: 78345959244.22.B0B6677 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf20.hostedemail.com (Postfix) with ESMTP id B12A2D0000B0 for ; Sat, 10 Jul 2021 08:11:41 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 5D867613BF; Sat, 10 Jul 2021 08:11:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625904700; bh=80vkX1XEmaWnY9YWGGJrbpCeJVSm+nQLZW7RcdCPUx0=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=mHbog3l2LduSeGAF3DzD/KSd70LZKz97K4+e0OK+p9Q7A46+y/P74ea+Ih6l2e8tG xHTneVNBxZaNZgaDfUrT1O/pC5xe0WiRXJkthCZVXjAIHgvZIhWiGd2WiXJMvBp0U8 2A78yXIrmqimkTlSxVPVvqvr3jJEKQ+w6ahNdq2c0fF05IX1hJ+Z6Qmdi4hWOmHyoP WvFFYTONAY/ql2803JuvGxJyZrgKiUyIBUmOmWruou+sFB4rd8VJpuwx7fe8VMprHK 5zfwtrgUhZ6/YOEaNUc6EMrEVXOI8zfFCuUegITcLFTzI6efeApaOvDGbYZ/7ZUUdH 4cLOVQ/LQi6Mg== Subject: Re: [f2fs-dev] [PATCH] f2fs: initialize page->private when using for our internal use To: Mel Gorman Cc: Matthew Wilcox , Jaegeuk Kim , linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mm@kvack.org References: <20210705052216.831989-1-jaegeuk@kernel.org> <20210706091211.GR3840@techsingularity.net> <85bb893b-0dc4-5f57-23ec-3f84814b7072@kernel.org> <20210707095706.GT3840@techsingularity.net> From: Chao Yu Message-ID: Date: Sat, 10 Jul 2021 16:11:38 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210707095706.GT3840@techsingularity.net> Content-Type: text/plain; charset=iso-8859-15; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: B12A2D0000B0 X-Stat-Signature: n9ucxxo7wb69wodjmtw1drot64i31zj8 Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=mHbog3l2; spf=pass (imf20.hostedemail.com: domain of chao@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=chao@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-HE-Tag: 1625904701-681936 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 2021/7/7 17:57, Mel Gorman wrote: > I think it would work but it would be preferable to find out why the > tail page has an order set in the first place. I've looked over Agreed. > mm/page_alloc.c and mm/compaction.c a few times and did not spot where > set_private_page(page, 0) is missed when it should be covered by > clear_page_guard or del_page_from_free_list :( I didn't enable CONFIG_DEBUG_PAGEALLOC, so we will expect page private should be cleared by del_page_from_free_list(), but I guess it only clears the buddy's private field rather than original page's, so I added below diff and check the dmesg, it looks stall private value in original page will be left commonly... Let me know if I missed something? --- mm/page_alloc.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a06bcfe6f786..1e7031ff548e 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1029,6 +1029,7 @@ static inline void __free_one_page(struct page *page, unsigned long combined_pfn; unsigned int max_order; struct page *buddy; + struct page *orig_page = page; bool to_tail; max_order = min_t(unsigned int, MAX_ORDER - 1, pageblock_order); @@ -1097,6 +1098,10 @@ static inline void __free_one_page(struct page *page, done_merging: set_buddy_order(page, order); + if (orig_page != page) { + if (WARN_ON_ONCE(orig_page->private)) + pr_info("2order:%x, origpage.private:%x", order, orig_page->private); + } if (fpi_flags & FPI_TO_TAIL) to_tail = true; -- 2.22.1 >