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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_GIT 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 D30FAC83000 for ; Wed, 29 Apr 2020 22:56:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F8702083B for ; Wed, 29 Apr 2020 22:56:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727789AbgD2W4l (ORCPT ); Wed, 29 Apr 2020 18:56:41 -0400 Received: from out30-133.freemail.mail.aliyun.com ([115.124.30.133]:47949 "EHLO out30-133.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726164AbgD2W4l (ORCPT ); Wed, 29 Apr 2020 18:56:41 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R161e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04407;MF=yang.shi@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0Tx2rN9y_1588200990; Received: from localhost(mailfrom:yang.shi@linux.alibaba.com fp:SMTPD_---0Tx2rN9y_1588200990) by smtp.aliyun-inc.com(127.0.0.1); Thu, 30 Apr 2020 06:56:38 +0800 From: Yang Shi To: kirill.shutemov@linux.intel.com, hughd@google.com, aarcange@redhat.com, akpm@linux-foundation.org Cc: yang.shi@linux.alibaba.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [linux-next PATCH 2/2] mm: khugepaged: don't have to put being freed page back to lru Date: Thu, 30 Apr 2020 06:56:22 +0800 Message-Id: <1588200982-69492-2-git-send-email-yang.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1588200982-69492-1-git-send-email-yang.shi@linux.alibaba.com> References: <1588200982-69492-1-git-send-email-yang.shi@linux.alibaba.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When khugepaged successfully isolated and copied data from base page to collapsed THP, the base page is about to be freed. So putting the page back to lru sounds not that productive since the page might be isolated by vmscan but it can't be reclaimed by vmscan since it can't be unmapped by try_to_unmap() at all. Actually khugepaged is the last user of this page so it can be freed directly. So, clearing active and unevictable flags, unlocking and dropping refcount from isolate instead of calling putback_lru_page(). Cc: Kirill A. Shutemov Cc: Hugh Dickins Cc: Andrea Arcangeli Signed-off-by: Yang Shi --- mm/khugepaged.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 0c8d30b..c131a90 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -559,6 +559,17 @@ void __khugepaged_exit(struct mm_struct *mm) static void release_pte_page(struct page *page) { mod_node_page_state(page_pgdat(page), + NR_ISOLATED_ANON + page_is_file_lru(page), -compound_nr(page)); + ClearPageActive(page); + ClearPageUnevictable(page); + unlock_page(page); + /* Drop refcount from isolate */ + put_page(page); +} + +static void release_pte_page_to_lru(struct page *page) +{ + mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON + page_is_file_lru(page), -compound_nr(page)); unlock_page(page); @@ -576,12 +587,12 @@ static void release_pte_pages(pte_t *pte, pte_t *_pte, page = pte_page(pteval); if (!pte_none(pteval) && !is_zero_pfn(pte_pfn(pteval)) && !PageCompound(page)) - release_pte_page(page); + release_pte_page_to_lru(page); } list_for_each_entry_safe(page, tmp, compound_pagelist, lru) { list_del(&page->lru); - release_pte_page(page); + release_pte_page_to_lru(page); } } -- 1.8.3.1