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, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT 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 1FC6AC433EA for ; Sat, 25 Jul 2020 13:00:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DF7F720674 for ; Sat, 25 Jul 2020 13:00:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DF7F720674 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BE6496B000A; Sat, 25 Jul 2020 09:00:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B95706B000C; Sat, 25 Jul 2020 09:00:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9BFB76B000A; Sat, 25 Jul 2020 09:00:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0100.hostedemail.com [216.40.44.100]) by kanga.kvack.org (Postfix) with ESMTP id 86FD46B0007 for ; Sat, 25 Jul 2020 09:00:32 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 4B5C227755 for ; Sat, 25 Jul 2020 13:00:32 +0000 (UTC) X-FDA: 77076607104.16.match95_1605abd26f50 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin16.hostedemail.com (Postfix) with ESMTP id 1A6EE100512AA for ; Sat, 25 Jul 2020 13:00:32 +0000 (UTC) X-HE-Tag: match95_1605abd26f50 X-Filterd-Recvd-Size: 6068 Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com [115.124.30.133]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Sat, 25 Jul 2020 13:00:30 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R181e4;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=20;SR=0;TI=SMTPD_---0U3l6fmD_1595682015; Received: from aliy8.localdomain(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0U3l6fmD_1595682015) by smtp.aliyun-inc.com(127.0.0.1); Sat, 25 Jul 2020 21:00:23 +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, kirill@shutemov.name, alexander.duyck@gmail.com, rong.a.chen@intel.com Cc: Andrea Arcangeli Subject: [PATCH v17 08/21] mm/thp: narrow lru locking Date: Sat, 25 Jul 2020 20:59:45 +0800 Message-Id: <1595681998-19193-9-git-send-email-alex.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1595681998-19193-1-git-send-email-alex.shi@linux.alibaba.com> References: <1595681998-19193-1-git-send-email-alex.shi@linux.alibaba.com> X-Rspamd-Queue-Id: 1A6EE100512AA X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 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: lru_lock and page cache xa_lock have no reason with current sequence, put them together isn't necessary. let's narrow the lru locking, but left the local_irq_disable to block interrupt re-entry and statistic update. Hugh Dickins point: split_huge_page_to_list() was already silly,to be using the _irqsave variant: it's just been taking sleeping locks, so would already be broken if entered with interrupts enabled. so we can save passing flags argument down to __split_huge_page(). Signed-off-by: Alex Shi Signed-off-by: Wei Yang Reviewed-by: Kirill A. Shutemov Cc: Hugh Dickins Cc: Kirill A. Shutemov Cc: Andrea Arcangeli Cc: Johannes Weiner Cc: Matthew Wilcox Cc: Andrew Morton Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/huge_memory.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 1fb4147ff854..d866b6e43434 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2423,7 +2423,7 @@ static void __split_huge_page_tail(struct page *head, int tail, } static void __split_huge_page(struct page *page, struct list_head *list, - pgoff_t end, unsigned long flags) + pgoff_t end) { struct page *head = compound_head(page); pg_data_t *pgdat = page_pgdat(head); @@ -2432,8 +2432,6 @@ static void __split_huge_page(struct page *page, struct list_head *list, unsigned long offset = 0; int i; - lruvec = mem_cgroup_page_lruvec(head, pgdat); - /* complete memcg works before add pages to LRU */ mem_cgroup_split_huge_fixup(head); @@ -2445,6 +2443,11 @@ static void __split_huge_page(struct page *page, struct list_head *list, xa_lock(&swap_cache->i_pages); } + /* prevent PageLRU to go away from under us, and freeze lru stats */ + spin_lock(&pgdat->lru_lock); + + lruvec = mem_cgroup_page_lruvec(head, pgdat); + for (i = HPAGE_PMD_NR - 1; i >= 1; i--) { __split_huge_page_tail(head, i, lruvec, list); /* Some pages can be beyond i_size: drop them from page cache */ @@ -2464,6 +2467,8 @@ static void __split_huge_page(struct page *page, struct list_head *list, } ClearPageCompound(head); + spin_unlock(&pgdat->lru_lock); + /* Caller disabled irqs, so they are still disabled here */ split_page_owner(head, HPAGE_PMD_ORDER); @@ -2481,8 +2486,7 @@ static void __split_huge_page(struct page *page, struct list_head *list, page_ref_add(head, 2); xa_unlock(&head->mapping->i_pages); } - - spin_unlock_irqrestore(&pgdat->lru_lock, flags); + local_irq_enable(); remap_page(head); @@ -2621,12 +2625,10 @@ bool can_split_huge_page(struct page *page, int *pextra_pins) int split_huge_page_to_list(struct page *page, struct list_head *list) { struct page *head = compound_head(page); - struct pglist_data *pgdata = NODE_DATA(page_to_nid(head)); struct deferred_split *ds_queue = get_deferred_split_queue(head); struct anon_vma *anon_vma = NULL; struct address_space *mapping = NULL; int count, mapcount, extra_pins, ret; - unsigned long flags; pgoff_t end; VM_BUG_ON_PAGE(is_huge_zero_page(head), head); @@ -2687,9 +2689,8 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) unmap_page(head); VM_BUG_ON_PAGE(compound_mapcount(head), head); - /* prevent PageLRU to go away from under us, and freeze lru stats */ - spin_lock_irqsave(&pgdata->lru_lock, flags); - + /* block interrupt reentry in xa_lock and spinlock */ + local_irq_disable(); if (mapping) { XA_STATE(xas, &mapping->i_pages, page_index(head)); @@ -2719,7 +2720,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) __dec_node_page_state(head, NR_FILE_THPS); } - __split_huge_page(page, list, end, flags); + __split_huge_page(page, list, end); if (PageSwapCache(head)) { swp_entry_t entry = { .val = page_private(head) }; @@ -2738,7 +2739,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) spin_unlock(&ds_queue->split_queue_lock); fail: if (mapping) xa_unlock(&mapping->i_pages); - spin_unlock_irqrestore(&pgdata->lru_lock, flags); + local_irq_enable(); remap_page(head); ret = -EBUSY; } -- 1.8.3.1