From patchwork Thu Apr 1 18:32:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Hansen X-Patchwork-Id: 12179301 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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 0B139C433ED for ; Thu, 1 Apr 2021 18:35:11 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8DBDA601FC for ; Thu, 1 Apr 2021 18:35:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8DBDA601FC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 190116B0099; Thu, 1 Apr 2021 14:35:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1409D6B009A; Thu, 1 Apr 2021 14:35:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 007636B009B; Thu, 1 Apr 2021 14:35:09 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0136.hostedemail.com [216.40.44.136]) by kanga.kvack.org (Postfix) with ESMTP id D64936B0099 for ; Thu, 1 Apr 2021 14:35:09 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 82C6A824999B for ; Thu, 1 Apr 2021 18:35:09 +0000 (UTC) X-FDA: 77984650338.27.970A6F3 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by imf28.hostedemail.com (Postfix) with ESMTP id 6CDBD2000249 for ; Thu, 1 Apr 2021 18:35:08 +0000 (UTC) IronPort-SDR: UGBzAAieN7fY2Pu37cJpHkEHe4OvFZieuePBgd1QHbEd3Ghj3IrHL+m/UnoNMO0fgx91SQFBBO riolCHKGl6xg== X-IronPort-AV: E=McAfee;i="6000,8403,9941"; a="172340681" X-IronPort-AV: E=Sophos;i="5.81,296,1610438400"; d="scan'208";a="172340681" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2021 11:35:07 -0700 IronPort-SDR: FuczjaOkjpIBLAKeW+4j5STy9zhzNKRb35N03V/HjmNAUK0ddH6LaPa48GdywqxY+TjJhK0mkI 4e1vxG0zsGRQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.81,296,1610438400"; d="scan'208";a="446390564" Received: from viggo.jf.intel.com (HELO localhost.localdomain) ([10.54.77.144]) by fmsmga002.fm.intel.com with ESMTP; 01 Apr 2021 11:35:06 -0700 Subject: [PATCH 05/10] mm/migrate: demote pages during reclaim To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org,Dave Hansen ,weixugc@google.com,yang.shi@linux.alibaba.com,rientjes@google.com,ying.huang@intel.com,dan.j.williams@intel.com,osalvador@suse.de From: Dave Hansen Date: Thu, 01 Apr 2021 11:32:25 -0700 References: <20210401183216.443C4443@viggo.jf.intel.com> In-Reply-To: <20210401183216.443C4443@viggo.jf.intel.com> Message-Id: <20210401183225.2EDC224F@viggo.jf.intel.com> X-Rspamd-Queue-Id: 6CDBD2000249 X-Stat-Signature: p5nhk98qed7dr6tkoahtbpqnksu1m3jp X-Rspamd-Server: rspam02 Received-SPF: none (linux.intel.com>: No applicable sender policy available) receiver=imf28; identity=mailfrom; envelope-from=""; helo=mga17.intel.com; client-ip=192.55.52.151 X-HE-DKIM-Result: none/none X-HE-Tag: 1617302108-169715 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: From: Dave Hansen This is mostly derived from a patch from Yang Shi: https://lore.kernel.org/linux-mm/1560468577-101178-10-git-send-email-yang.shi@linux.alibaba.com/ Add code to the reclaim path (shrink_page_list()) to "demote" data to another NUMA node instead of discarding the data. This always avoids the cost of I/O needed to read the page back in and sometimes avoids the writeout cost when the pagee is dirty. A second pass through shrink_page_list() will be made if any demotions fail. This essentally falls back to normal reclaim behavior in the case that demotions fail. Previous versions of this patch may have simply failed to reclaim pages which were eligible for demotion but were unable to be demoted in practice. Note: This just adds the start of infratructure for migration. It is actually disabled next to the FIXME in migrate_demote_page_ok(). Signed-off-by: Dave Hansen Cc: Wei Xu Cc: Yang Shi Cc: David Rientjes Cc: Huang Ying Cc: Dan Williams Cc: osalvador Reviewed-by: Oscar Salvador Reviewed-by: Wei Xu --- changes from 20210122: * move from GFP_HIGHUSER -> GFP_HIGHUSER_MOVABLE (Ying) changes from 202010: * add MR_NUMA_MISPLACED to trace MIGRATE_REASON define * make migrate_demote_page_ok() static, remove 'sc' arg until later patch * remove unnecessary alloc_demote_page() hugetlb warning * Simplify alloc_demote_page() gfp mask. Depend on __GFP_NORETRY to make it lightweight instead of fancier stuff like leaving out __GFP_IO/FS. * Allocate migration page with alloc_migration_target() instead of allocating directly. changes from 20200730: * Add another pass through shrink_page_list() when demotion fails. changes from 20210302: * Use __GFP_THISNODE and revise the comment explaining the GFP mask constructionn --- b/include/linux/migrate.h | 9 ++++ b/include/trace/events/migrate.h | 3 - b/mm/vmscan.c | 82 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 93 insertions(+), 1 deletion(-) diff -puN include/linux/migrate.h~demote-with-migrate_pages include/linux/migrate.h --- a/include/linux/migrate.h~demote-with-migrate_pages 2021-03-31 15:17:15.842000251 -0700 +++ b/include/linux/migrate.h 2021-03-31 15:17:15.853000251 -0700 @@ -27,6 +27,7 @@ enum migrate_reason { MR_MEMPOLICY_MBIND, MR_NUMA_MISPLACED, MR_CONTIG_RANGE, + MR_DEMOTION, MR_TYPES }; @@ -196,6 +197,14 @@ struct migrate_vma { int migrate_vma_setup(struct migrate_vma *args); void migrate_vma_pages(struct migrate_vma *migrate); void migrate_vma_finalize(struct migrate_vma *migrate); +int next_demotion_node(int node); + +#else /* CONFIG_MIGRATION disabled: */ + +static inline int next_demotion_node(int node) +{ + return NUMA_NO_NODE; +} #endif /* CONFIG_MIGRATION */ diff -puN include/trace/events/migrate.h~demote-with-migrate_pages include/trace/events/migrate.h --- a/include/trace/events/migrate.h~demote-with-migrate_pages 2021-03-31 15:17:15.846000251 -0700 +++ b/include/trace/events/migrate.h 2021-03-31 15:17:15.853000251 -0700 @@ -20,7 +20,8 @@ EM( MR_SYSCALL, "syscall_or_cpuset") \ EM( MR_MEMPOLICY_MBIND, "mempolicy_mbind") \ EM( MR_NUMA_MISPLACED, "numa_misplaced") \ - EMe(MR_CONTIG_RANGE, "contig_range") + EM( MR_CONTIG_RANGE, "contig_range") \ + EMe(MR_DEMOTION, "demotion") /* * First define the enums in the above macros to be exported to userspace diff -puN mm/vmscan.c~demote-with-migrate_pages mm/vmscan.c --- a/mm/vmscan.c~demote-with-migrate_pages 2021-03-31 15:17:15.848000251 -0700 +++ b/mm/vmscan.c 2021-03-31 15:17:15.856000251 -0700 @@ -41,6 +41,7 @@ #include #include #include +#include #include #include #include @@ -1035,6 +1036,23 @@ static enum page_references page_check_r return PAGEREF_RECLAIM; } +static bool migrate_demote_page_ok(struct page *page) +{ + int next_nid = next_demotion_node(page_to_nid(page)); + + VM_BUG_ON_PAGE(!PageLocked(page), page); + VM_BUG_ON_PAGE(PageHuge(page), page); + VM_BUG_ON_PAGE(PageLRU(page), page); + + if (next_nid == NUMA_NO_NODE) + return false; + if (PageTransHuge(page) && !thp_migration_supported()) + return false; + + // FIXME: actually enable this later in the series + return false; +} + /* Check if a page is dirty or under writeback */ static void page_check_dirty_writeback(struct page *page, bool *dirty, bool *writeback) @@ -1065,6 +1083,46 @@ static void page_check_dirty_writeback(s mapping->a_ops->is_dirty_writeback(page, dirty, writeback); } +static struct page *alloc_demote_page(struct page *page, unsigned long node) +{ + struct migration_target_control mtc = { + /* + * Allocate from 'node', or fail the quickly and quietly. + * When this happens, 'page; will likely just be discarded + * instead of migrated. + */ + .gfp_mask = GFP_HIGHUSER_MOVABLE | __GFP_NORETRY | + __GFP_THISNODE | __GFP_NOWARN, + .nid = node + }; + + return alloc_migration_target(page, (unsigned long)&mtc); +} + +/* + * Take pages on @demote_list and attempt to demote them to + * another node. Pages which are not demoted are left on + * @demote_pages. + */ +static unsigned int demote_page_list(struct list_head *demote_pages, + struct pglist_data *pgdat, + struct scan_control *sc) +{ + int target_nid = next_demotion_node(pgdat->node_id); + unsigned int nr_succeeded = 0; + int err; + + if (list_empty(demote_pages)) + return 0; + + /* Demotion ignores all cpuset and mempolicy settings */ + err = migrate_pages(demote_pages, alloc_demote_page, NULL, + target_nid, MIGRATE_ASYNC, MR_DEMOTION, + &nr_succeeded); + + return nr_succeeded; +} + /* * shrink_page_list() returns the number of reclaimed pages */ @@ -1076,12 +1134,15 @@ static unsigned int shrink_page_list(str { LIST_HEAD(ret_pages); LIST_HEAD(free_pages); + LIST_HEAD(demote_pages); unsigned int nr_reclaimed = 0; unsigned int pgactivate = 0; + bool do_demote_pass = true; memset(stat, 0, sizeof(*stat)); cond_resched(); +retry: while (!list_empty(page_list)) { struct address_space *mapping; struct page *page; @@ -1231,6 +1292,16 @@ static unsigned int shrink_page_list(str } /* + * Before reclaiming the page, try to relocate + * its contents to another node. + */ + if (do_demote_pass && migrate_demote_page_ok(page)) { + list_add(&page->lru, &demote_pages); + unlock_page(page); + continue; + } + + /* * Anonymous process memory has backing store? * Try to allocate it some swap space here. * Lazyfree page could be freed directly @@ -1480,6 +1551,17 @@ keep: list_add(&page->lru, &ret_pages); VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page), page); } + /* 'page_list' is always empty here */ + + /* Migrate pages selected for demotion */ + nr_reclaimed += demote_page_list(&demote_pages, pgdat, sc); + /* Pages that could not be demoted are still in @demote_pages */ + if (!list_empty(&demote_pages)) { + /* Pages which failed to demoted go back on @page_list for retry: */ + list_splice_init(&demote_pages, page_list); + do_demote_pass = false; + goto retry; + } pgactivate = stat->nr_activate[0] + stat->nr_activate[1];