From patchwork Sat Aug 1 04:09:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Shi X-Patchwork-Id: 11695887 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6B1FF14B7 for ; Sat, 1 Aug 2020 04:10:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 421AD206FA for ; Sat, 1 Aug 2020 04:10:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 421AD206FA 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 783198D0084; Sat, 1 Aug 2020 00:10:25 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 734228D0081; Sat, 1 Aug 2020 00:10:25 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6719E8D0084; Sat, 1 Aug 2020 00:10:25 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0075.hostedemail.com [216.40.44.75]) by kanga.kvack.org (Postfix) with ESMTP id 5109D8D0081 for ; Sat, 1 Aug 2020 00:10:25 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id D677C824805A for ; Sat, 1 Aug 2020 04:10:24 +0000 (UTC) X-FDA: 77100672768.04.paper31_1e0842226f89 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin04.hostedemail.com (Postfix) with ESMTP id 9491E800B4E7 for ; Sat, 1 Aug 2020 04:10:24 +0000 (UTC) X-Spam-Summary: 1,0,0,e5dba5c05abe7a99,d41d8cd98f00b204,alex.shi@linux.alibaba.com,,RULES_HIT:41:69:355:379:541:800:960:966:973:981:988:989:1260:1261:1345:1359:1431:1437:1535:1544:1711:1730:1747:1777:1792:2196:2198:2199:2200:2393:2559:2562:2895:2904:3138:3139:3140:3141:3142:3355:3865:3867:3868:3870:3872:4321:4385:4605:5007:6261:7514:8957:9010:9592:10004:11026:11473:11658:11914:12043:12296:12297:12438:12555:12679:12895:13846:14096:14181:14394:14721:21060:21080:21451:21627:21740:21966:30054:30070,0,RBL:115.124.30.57:@linux.alibaba.com:.lbl8.mailshell.net-62.20.2.100 64.201.201.201;04ygdw8ed7xnno44wkwuybtqte7beypbrneor45ngos58drfmgue9znkitragyw.r4jd531fbwfszn53uo79kkgoibp5w11ugndxdbg1d3ycho58utd1bda49o6jcod.s-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:25,LUA_SUMMARY:none X-HE-Tag: paper31_1e0842226f89 X-Filterd-Recvd-Size: 5874 Received: from out30-57.freemail.mail.aliyun.com (out30-57.freemail.mail.aliyun.com [115.124.30.57]) by imf16.hostedemail.com (Postfix) with ESMTP for ; Sat, 1 Aug 2020 04:10:22 +0000 (UTC) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R861e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01419;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=9;SR=0;TI=SMTPD_---0U4Mybap_1596254964; Received: from aliy8.localdomain(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0U4Mybap_1596254964) by smtp.aliyun-inc.com(127.0.0.1); Sat, 01 Aug 2020 12:09:25 +0800 From: Alex Shi To: Andrew Morton Cc: Wei Yang , Hugh Dickins , "Kirill A. Shutemov" , Andrea Arcangeli , Johannes Weiner , Matthew Wilcox , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 4/4] mm/thp: narrow lru locking Date: Sat, 1 Aug 2020 12:09:17 +0800 Message-Id: <1596254957-22560-4-git-send-email-alex.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1596254957-22560-1-git-send-email-alex.shi@linux.alibaba.com> References: <1596254957-22560-1-git-send-email-alex.shi@linux.alibaba.com> X-Rspamd-Queue-Id: 9491E800B4E7 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 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 dfe7378ab4be..070480e66bf4 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2398,7 +2398,7 @@ 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); @@ -2407,8 +2407,6 @@ 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); @@ -2420,6 +2418,11 @@ 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 */ @@ -2439,6 +2442,8 @@ 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); @@ -2456,8 +2461,7 @@ 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); @@ -2596,12 +2600,10 @@ 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); @@ -2662,9 +2664,8 @@ 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)); @@ -2694,7 +2695,7 @@ 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) }; @@ -2713,7 +2714,7 @@ 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; }