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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,URIBL_BLOCKED,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 CD23CC55199 for ; Mon, 27 Apr 2020 07:03:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B356D2075B for ; Mon, 27 Apr 2020 07:03:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726763AbgD0HDr (ORCPT ); Mon, 27 Apr 2020 03:03:47 -0400 Received: from out30-57.freemail.mail.aliyun.com ([115.124.30.57]:49427 "EHLO out30-57.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726699AbgD0HDm (ORCPT ); Mon, 27 Apr 2020 03:03:42 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R111e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01358;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=17;SR=0;TI=SMTPD_---0TwlaTjU_1587971016; Received: from localhost(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0TwlaTjU_1587971016) by smtp.aliyun-inc.com(127.0.0.1); Mon, 27 Apr 2020 15:03:37 +0800 From: Alex Shi To: akpm@linux-foundation.org, mgorman@techsingularity.net, tj@kernel.org, hughd@google.com, khlebnikov@yandex-team.ru, daniel.m.jordan@oracle.com, yang.shi@linux.alibaba.com, willy@infradead.org, hannes@cmpxchg.org, lkp@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, shakeelb@google.com, iamjoonsoo.kim@lge.com, richard.weiyang@gmail.com Cc: Alex Shi Subject: [PATCH v10 09/15] mm/compaction: do page isolation first in compaction Date: Mon, 27 Apr 2020 15:02:58 +0800 Message-Id: <1587970985-21629-10-git-send-email-alex.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1587970985-21629-1-git-send-email-alex.shi@linux.alibaba.com> References: <1587970985-21629-1-git-send-email-alex.shi@linux.alibaba.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Johannes Weiner has suggested: "So here is a crazy idea that may be worth exploring: Right now, pgdat->lru_lock protects both PageLRU *and* the lruvec's linked list. Can we make PageLRU atomic and use it to stabilize the lru_lock instead, and then use the lru_lock only serialize list operations? ..." Yes, this patch is doing so on __isolate_lru_page which is the core page isolation func in compaction and shrinking path. With this patch, the compaction will only deal the PageLRU set and now isolated pages to skip the just alloced page which no LRU bit. And the isolation could exclusive the other isolations in memcg move_account, page migrations and thp split_huge_page. As a side effect, PageLRU may be cleared during shrink_inactive_list path for isolation reason. If so, we can skip that page. Suggested-by: Johannes Weiner Signed-off-by: Alex Shi Cc: Andrew Morton Cc: Matthew Wilcox Cc: Hugh Dickins Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org --- include/linux/swap.h | 2 +- mm/compaction.c | 25 +++++++++++++++++-------- mm/vmscan.c | 38 ++++++++++++++++++++++---------------- 3 files changed, 40 insertions(+), 25 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index 4e13d0bb8e82..20e4b9f93529 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -351,7 +351,7 @@ extern void lru_cache_add_active_or_unevictable(struct page *page, extern unsigned long zone_reclaimable_pages(struct zone *zone); extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, gfp_t gfp_mask, nodemask_t *mask); -extern int __isolate_lru_page(struct page *page, isolate_mode_t mode); +extern int __isolate_lru_page_prepare(struct page *page, isolate_mode_t mode); extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, unsigned long nr_pages, gfp_t gfp_mask, diff --git a/mm/compaction.c b/mm/compaction.c index 46f0fcc93081..3d33f36e2126 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -950,6 +950,23 @@ static bool too_many_isolated(pg_data_t *pgdat) if (!(cc->gfp_mask & __GFP_FS) && page_mapping(page)) goto isolate_fail; + if (__isolate_lru_page_prepare(page, isolate_mode) != 0) + goto isolate_fail; + + /* + * Be careful not to clear PageLRU until after we're + * sure the page is not being freed elsewhere -- the + * page release code relies on it. + */ + if (unlikely(!get_page_unless_zero(page))) + goto isolate_fail; + + /* Try isolate the page */ + if (!TestClearPageLRU(page)) { + put_page(page); + goto isolate_fail; + } + /* If we already hold the lock, we can skip some rechecking */ if (!locked) { locked = compact_lock_irqsave(&pgdat->lru_lock, @@ -962,10 +979,6 @@ static bool too_many_isolated(pg_data_t *pgdat) goto isolate_abort; } - /* Recheck PageLRU and PageCompound under lock */ - if (!PageLRU(page)) - goto isolate_fail; - /* * Page become compound since the non-locked check, * and it's on LRU. It can only be a THP so the order @@ -979,10 +992,6 @@ static bool too_many_isolated(pg_data_t *pgdat) lruvec = mem_cgroup_page_lruvec(page, pgdat); - /* Try isolate the page */ - if (__isolate_lru_page(page, isolate_mode) != 0) - goto isolate_fail; - /* The whole page is taken off the LRU; skip the tail pages. */ if (PageCompound(page)) low_pfn += compound_nr(page) - 1; diff --git a/mm/vmscan.c b/mm/vmscan.c index 50566056b95a..33568e795640 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1521,7 +1521,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone, * * returns 0 on success, -ve errno on failure. */ -int __isolate_lru_page(struct page *page, isolate_mode_t mode) +int __isolate_lru_page_prepare(struct page *page, isolate_mode_t mode) { int ret = -EINVAL; @@ -1575,20 +1575,9 @@ int __isolate_lru_page(struct page *page, isolate_mode_t mode) if ((mode & ISOLATE_UNMAPPED) && page_mapped(page)) return ret; - if (likely(get_page_unless_zero(page))) { - /* - * Be careful not to clear PageLRU until after we're - * sure the page is not being freed elsewhere -- the - * page release code relies on it. - */ - ClearPageLRU(page); - ret = 0; - } - - return ret; + return 0; } - /* * Update LRU sizes after isolating pages. The LRU size updates must * be complete before mem_cgroup_update_lru_size due to a santity check. @@ -1672,17 +1661,34 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, * only when the page is being freed somewhere else. */ scan += nr_pages; - switch (__isolate_lru_page(page, mode)) { + switch (__isolate_lru_page_prepare(page, mode)) { case 0: + /* + * Be careful not to clear PageLRU until after we're + * sure the page is not being freed elsewhere -- the + * page release code relies on it. + */ + if (unlikely(!get_page_unless_zero(page))) + goto busy; + + if (!TestClearPageLRU(page)) { + /* + * This page may in other isolation path, + * but we still hold lru_lock. + */ + put_page(page); + goto busy; + } + nr_taken += nr_pages; nr_zone_taken[page_zonenum(page)] += nr_pages; list_move(&page->lru, dst); break; - +busy: case -EBUSY: /* else it is being freed elsewhere */ list_move(&page->lru, src); - continue; + break; default: BUG(); -- 1.8.3.1