From patchwork Wed Mar 10 16:14:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Minchan Kim X-Patchwork-Id: 12128385 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=-17.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,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 CA870C433E6 for ; Wed, 10 Mar 2021 16:15:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9ECC564FBC for ; Wed, 10 Mar 2021 16:15:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231490AbhCJQOo (ORCPT ); Wed, 10 Mar 2021 11:14:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231295AbhCJQOf (ORCPT ); Wed, 10 Mar 2021 11:14:35 -0500 Received: from mail-pg1-x52a.google.com (mail-pg1-x52a.google.com [IPv6:2607:f8b0:4864:20::52a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88FFFC061760; Wed, 10 Mar 2021 08:14:35 -0800 (PST) Received: by mail-pg1-x52a.google.com with SMTP id o38so11698590pgm.9; Wed, 10 Mar 2021 08:14:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=txDbp7Wx2vX6YjkhEkbwKwYgP5c1xPLVUUyDZKo4vU0=; b=RqZkiJOX3AzUZI0tbgk2ZL2AhsevK4JuBLj9cn+6ODa4Ec8DKsNAVu3OOcWPsBeAn+ jfFLTa5qDcsP53lb9sX/+eYM2fVU+IGHtE36xW1v1HW9p1oS7ftygo5d9gmSkAFQEkwH lEONCRwxPVxtQ12E6VAsz1FiN7XXoMnrqQLfOrhFjt1SSH1SQ9pzIBHgGYM94yHLVniC AZ2eJSQj+5Kv9eA/ow6Qi413f+H+9qVltIPQFLCehT0dlVaTfW+ghQYvvpkK+PNo6sN8 L3wsMig1XfKGIdQUXxTpHWNVBcOpOHHiY2Y+Y05XABIY7UmzKRE81/UK/C3GvEoWMxEX gRew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :mime-version:content-transfer-encoding; bh=txDbp7Wx2vX6YjkhEkbwKwYgP5c1xPLVUUyDZKo4vU0=; b=gzxPG8SIkgok5IkbY/RjJ1ojZcHwsLLaVYO90bwCyCKEb7+Y5XZXGX/8hd7aFifWUK 8v3jbX04TmK7JuMSybFahsFzMg0LpeDQvdXou+BdMwVqpnoAY3a0Ef1/NRR7U+wKwHke ai3iFQIbm8frwr+vYC6KldsTDEAbfznX8Hl/jpywPynJVKwcYGWRYPUP82MifGNwqM9P YkPRwKPKaGvnCpNKSIuM8co3jc9HgrKtmg3+gv6EEXj4L5KydqoVeWGxktAPiUIhiXZK 4x28RuGFu7fOKC9tWb9j9YvtFuR1DwIemhIXnI4h6C4RvtKd5060Wj+22AeEETWM5thy C0BQ== X-Gm-Message-State: AOAM5313pO73wPB9XPilh6cq3097ZWp69Rx0U+jUHeGrpBH2JOEazH1I lHsHgRQGaTKxbrEWNfsn/xE= X-Google-Smtp-Source: ABdhPJyWcNFIgTYVyW1GyKn81RImjZdoe1yYrSeMfSwu8whqA4bM2QbmpiG4gnMx36igaAIn9kSfRQ== X-Received: by 2002:a65:6642:: with SMTP id z2mr3380674pgv.214.1615392875014; Wed, 10 Mar 2021 08:14:35 -0800 (PST) Received: from bbox-1.mtv.corp.google.com ([2620:15c:211:201:64cb:74c7:f2c:e5e0]) by smtp.gmail.com with ESMTPSA id d1sm7121189pjc.24.2021.03.10.08.14.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Mar 2021 08:14:34 -0800 (PST) Sender: Minchan Kim From: Minchan Kim To: Andrew Morton Cc: linux-mm , LKML , joaodias@google.com, surenb@google.com, cgoldswo@codeaurora.org, willy@infradead.org, mhocko@suse.com, david@redhat.com, vbabka@suse.cz, linux-fsdevel@vger.kernel.org, Minchan Kim Subject: [PATCH v3 1/3] mm: replace migrate_prep with lru_add_drain_all Date: Wed, 10 Mar 2021 08:14:27 -0800 Message-Id: <20210310161429.399432-1-minchan@kernel.org> X-Mailer: git-send-email 2.30.1.766.gb4fecdf3b7-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Currently, migrate_prep is merely a wrapper of lru_cache_add_all. There is not much to gain from having additional abstraction. Use lru_add_drain_all instead of migrate_prep, which would be more descriptive. note: migrate_prep_local in compaction.c changed into lru_add_drain to avoid CPU schedule cost with involving many other CPUs to keep keep old behavior. Signed-off-by: Minchan Kim Acked-by: Michal Hocko Reviewed-by: David Hildenbrand --- include/linux/migrate.h | 5 ----- mm/compaction.c | 3 ++- mm/mempolicy.c | 4 ++-- mm/migrate.c | 24 +----------------------- mm/page_alloc.c | 2 +- mm/swap.c | 5 +++++ 6 files changed, 11 insertions(+), 32 deletions(-) diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 3a389633b68f..6155d97ec76c 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -45,8 +45,6 @@ extern struct page *alloc_migration_target(struct page *page, unsigned long priv extern int isolate_movable_page(struct page *page, isolate_mode_t mode); extern void putback_movable_page(struct page *page); -extern void migrate_prep(void); -extern void migrate_prep_local(void); extern void migrate_page_states(struct page *newpage, struct page *page); extern void migrate_page_copy(struct page *newpage, struct page *page); extern int migrate_huge_page_move_mapping(struct address_space *mapping, @@ -66,9 +64,6 @@ static inline struct page *alloc_migration_target(struct page *page, static inline int isolate_movable_page(struct page *page, isolate_mode_t mode) { return -EBUSY; } -static inline int migrate_prep(void) { return -ENOSYS; } -static inline int migrate_prep_local(void) { return -ENOSYS; } - static inline void migrate_page_states(struct page *newpage, struct page *page) { } diff --git a/mm/compaction.c b/mm/compaction.c index e04f4476e68e..3be017ececc0 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -2319,7 +2319,8 @@ compact_zone(struct compact_control *cc, struct capture_control *capc) trace_mm_compaction_begin(start_pfn, cc->migrate_pfn, cc->free_pfn, end_pfn, sync); - migrate_prep_local(); + /* lru_add_drain_all could be expensive with involving other CPUs */ + lru_add_drain(); while ((ret = compact_finished(cc)) == COMPACT_CONTINUE) { int err; diff --git a/mm/mempolicy.c b/mm/mempolicy.c index ab51132547b8..fc024e97be37 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1124,7 +1124,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, int err = 0; nodemask_t tmp; - migrate_prep(); + lru_add_drain_all(); mmap_read_lock(mm); @@ -1323,7 +1323,7 @@ static long do_mbind(unsigned long start, unsigned long len, if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) { - migrate_prep(); + lru_add_drain_all(); } { NODEMASK_SCRATCH(scratch); diff --git a/mm/migrate.c b/mm/migrate.c index 62b81d5257aa..45f925e10f5a 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -57,28 +57,6 @@ #include "internal.h" -/* - * migrate_prep() needs to be called before we start compiling a list of pages - * to be migrated using isolate_lru_page(). If scheduling work on other CPUs is - * undesirable, use migrate_prep_local() - */ -void migrate_prep(void) -{ - /* - * Clear the LRU lists so pages can be isolated. - * Note that pages may be moved off the LRU after we have - * drained them. Those pages will fail to migrate like other - * pages that may be busy. - */ - lru_add_drain_all(); -} - -/* Do the necessary work of migrate_prep but not if it involves other CPUs */ -void migrate_prep_local(void) -{ - lru_add_drain(); -} - int isolate_movable_page(struct page *page, isolate_mode_t mode) { struct address_space *mapping; @@ -1769,7 +1747,7 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, int start, i; int err = 0, err1; - migrate_prep(); + lru_add_drain_all(); for (i = start = 0; i < nr_pages; i++) { const void __user *p; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 2e8348936df8..f05a8db741ca 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8467,7 +8467,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc, .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL, }; - migrate_prep(); + lru_add_drain_all(); while (pfn < end || !list_empty(&cc->migratepages)) { if (fatal_signal_pending(current)) { diff --git a/mm/swap.c b/mm/swap.c index 31b844d4ed94..441d1ae1f285 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -729,6 +729,11 @@ static void lru_add_drain_per_cpu(struct work_struct *dummy) } /* + * lru_add_drain_all() usually needs to be called before we start compiling + * a list of pages to be migrated using isolate_lru_page(). Note that pages + * may be moved off the LRU after we have drained them. Those pages will + * fail to migrate like other pages that may be busy. + * * Doesn't need any cpu hotplug locking because we do rely on per-cpu * kworkers being shut down before our page_alloc_cpu_dead callback is * executed on the offlined cpu.