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=unavailable 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 A7079C07E95 for ; Sat, 10 Jul 2021 08:12:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 82AEC613BF for ; Sat, 10 Jul 2021 08:12:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231976AbhGJIO1 (ORCPT ); Sat, 10 Jul 2021 04:14:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:44878 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230007AbhGJIOZ (ORCPT ); Sat, 10 Jul 2021 04:14:25 -0400 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 >