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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 1AF85C433E1 for ; Wed, 19 Aug 2020 03:50:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EAD192078B for ; Wed, 19 Aug 2020 03:50:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597809055; bh=tPVEsWYE/oGKT4h8PhsxBMvEfRlyRQLihL/LccB8RY8=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=HfHAXAKh86boOmFcCb2GFkIyq5zB8Zz6sO8AKBwQdVzce974cNscj7oDki3dQswSz Bhee8SR3ONDd70AeRG5NTs9xsAoHesoqR2iemMf/sjeLitspXRVmLHEmOnZ4UUh13C D1X/78tHoSbR9U8kI1SXIQpzkq6T4bBm5xLCluTA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726703AbgHSDuy (ORCPT ); Tue, 18 Aug 2020 23:50:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:43914 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726318AbgHSDuy (ORCPT ); Tue, 18 Aug 2020 23:50:54 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 05A0F207BB; Wed, 19 Aug 2020 03:50:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597809053; bh=tPVEsWYE/oGKT4h8PhsxBMvEfRlyRQLihL/LccB8RY8=; h=Date:From:To:Subject:In-Reply-To:From; b=P2JOdFQCzok95/C3oeKakTbBlRqPyiTkPiyoVpy361xA8BAQjxcKHxX31NbiK7Rm9 +AS18PzfarX7DQGFjSpRCpUPeKxiACbsf92cyf7O+MUDGzqD7iBwooRMyq+s9tMGWe p9my+QRb/Bm22hEPIv8Nfd5kdXO5V1BKk/WikAZI= Date: Tue, 18 Aug 2020 20:50:52 -0700 From: Andrew Morton To: aarcange@redhat.com, alex.shi@linux.alibaba.com, guro@fb.com, hannes@cmpxchg.org, hughd@google.com, kirill.shutemov@linux.intel.com, mhocko@kernel.org, mhocko@suse.com, mm-commits@vger.kernel.org, richard.weiyang@gmail.com, vdavydov.dev@gmail.com, willy@infradead.org Subject: + mm-thp-narrow-lru-locking.patch added to -mm tree Message-ID: <20200819035052.vE0CvFmqd%akpm@linux-foundation.org> In-Reply-To: <20200814172939.55d6d80b6e21e4241f1ee1f3@linux-foundation.org> User-Agent: s-nail v14.8.16 Sender: mm-commits-owner@vger.kernel.org Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm/thp: narrow lru locking has been added to the -mm tree. Its filename is mm-thp-narrow-lru-locking.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-thp-narrow-lru-locking.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-thp-narrow-lru-locking.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Alex Shi Subject: mm/thp: narrow lru locking 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(). Link: http://lkml.kernel.org/r/1597144232-11370-6-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Alex Shi Signed-off-by: Wei Yang Reviewed-by: Kirill A. Shutemov Cc: Hugh Dickins Cc: Andrea Arcangeli Cc: Johannes Weiner Cc: Matthew Wilcox Cc: Michal Hocko Cc: Michal Hocko Cc: Roman Gushchin Cc: Vladimir Davydov Signed-off-by: Andrew Morton --- mm/huge_memory.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) --- a/mm/huge_memory.c~mm-thp-narrow-lru-locking +++ a/mm/huge_memory.c @@ -2397,7 +2397,7 @@ static void __split_huge_page_tail(struc } 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); @@ -2406,8 +2406,6 @@ static void __split_huge_page(struct pag 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); @@ -2419,6 +2417,11 @@ static void __split_huge_page(struct pag 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 */ @@ -2438,6 +2441,8 @@ static void __split_huge_page(struct pag } ClearPageCompound(head); + spin_unlock(&pgdat->lru_lock); + /* Caller disabled irqs, so they are still disabled here */ split_page_owner(head, HPAGE_PMD_ORDER); @@ -2455,8 +2460,7 @@ static void __split_huge_page(struct pag page_ref_add(head, 2); xa_unlock(&head->mapping->i_pages); } - - spin_unlock_irqrestore(&pgdat->lru_lock, flags); + local_irq_enable(); remap_page(head); @@ -2595,12 +2599,10 @@ bool can_split_huge_page(struct page *pa 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); @@ -2661,9 +2663,8 @@ int split_huge_page_to_list(struct page 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)); @@ -2693,7 +2694,7 @@ int split_huge_page_to_list(struct page __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) }; @@ -2712,7 +2713,7 @@ int split_huge_page_to_list(struct page 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; } _ Patches currently in -mm which might be from alex.shi@linux.alibaba.com are mm-memcg-warning-on-memcg-after-readahead-page-charged.patch mm-memcg-remove-useless-check-on-page-mem_cgroup.patch mm-thp-move-lru_add_page_tail-func-to-huge_memoryc.patch mm-thp-clean-up-lru_add_page_tail.patch mm-thp-remove-code-path-which-never-got-into.patch mm-thp-narrow-lru-locking.patch