From patchwork Tue Mar 2 21:09:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Minchan Kim X-Patchwork-Id: 12112957 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=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 506DCC433E0 for ; Wed, 3 Mar 2021 05:56:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0F8AE64EC3 for ; Wed, 3 Mar 2021 05:56:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1450150AbhCCFap (ORCPT ); Wed, 3 Mar 2021 00:30:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40832 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1383571AbhCBVQ2 (ORCPT ); Tue, 2 Mar 2021 16:16:28 -0500 Received: from mail-pf1-x434.google.com (mail-pf1-x434.google.com [IPv6:2607:f8b0:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 38EB6C061788; Tue, 2 Mar 2021 13:09:55 -0800 (PST) Received: by mail-pf1-x434.google.com with SMTP id l7so10422862pfd.3; Tue, 02 Mar 2021 13:09:55 -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=JLttgNfMq3Kov3tU2taLK4BnRrz26Wpbqh7r9Pz+2zU=; b=ZUR/GOeR+rzGWfJrXDJ9R713bPE1Gv+0qMwgH2DHrTXOjiaUpleSR+L5jDBb4MH8O9 2aqJZgBtXRsaXqa1eHwHhJKzzYu4bKnwyu4yDfFP/o0ZeVbfQuPzvbBF0hU+2i+xLzWs gAgSOGdk76OpM0zP8Cq49cvh7Rw35W6ffYDZOngiT43r2V+GmSUv3d5jb1783ziIYG5q atYGoU0dcHGlYydbwXFI/yoFKojuhj54+Y+PEqNWzvKjo4cpikd0AP9UpzHjIg1GUx99 pGKFU7QtutnjsrqgCkHqNl00PxuKzh+OslSm0WYp03iBV/kgA4ajgIRTvrq9WJrkbQ/j OUGQ== 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=JLttgNfMq3Kov3tU2taLK4BnRrz26Wpbqh7r9Pz+2zU=; b=fucB1pvrp21eeVBDc5gEblTHfkW5yPOovYGLVyRX00hcZ6foPiXi2YKCMRsfYpV263 4QcZxQb2ItMXMYB+0A0YrBLrp21GhyOLpKgOZH6yQF4rEn5nFysaHticoWicwRH+EXpU pqcj1NRa1LTRVf4+95alEb3ih7tDJOj5u21v1eU1l+CbCK+1S3NfMyrEtm2uzJ4GnOc6 BqphVGqf8BM8YTAzbw1eRWEMTtEgAPliMI9IMSad8WgOvLws6fbTzui70QeNUgJrzrKi 3kcrqGopG4OkcgtroCyohV4GEeJZeTM4X6ClHo7A4sSmTG9nUyw01jeNiIZlrUWwy3VW 76Yg== X-Gm-Message-State: AOAM5331i7AQ8QrVuC1JBlGzPSVUAYx2AIYRlLKAa1Sgw21TiyxEBb4k VQSLCRWz6CjBfguUQ4Rc4Rc= X-Google-Smtp-Source: ABdhPJzAIvods/GCYgMUuU2epYNi8LvhsVZq+3AIjibtUN4omfOt0B/q0+Yex7vBczbTbe3px3gFAg== X-Received: by 2002:a63:610:: with SMTP id 16mr18860021pgg.423.1614719394641; Tue, 02 Mar 2021 13:09:54 -0800 (PST) Received: from bbox-1.mtv.corp.google.com ([2620:15c:211:201:c87:c34:99dc:ba23]) by smtp.gmail.com with ESMTPSA id w17sm18980572pgg.41.2021.03.02.13.09.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 02 Mar 2021 13:09:53 -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 1/2] mm: disable LRU pagevec during the migration temporarily Date: Tue, 2 Mar 2021 13:09:48 -0800 Message-Id: <20210302210949.2440120-1-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 LRU pagevec holds refcount of pages until the pagevec are drained. It could prevent migration since the refcount of the page is greater than the expection in migration logic. To mitigate the issue, callers of migrate_pages drains LRU pagevec via migrate_prep or lru_add_drain_all before migrate_pages call. However, it's not enough because pages coming into pagevec after the draining call still could stay at the pagevec so it could keep preventing page migration. Since some callers of migrate_pages have retrial logic with LRU draining, the page would migrate at next trail but it is still fragile in that it doesn't close the fundamental race between upcoming LRU pages into pagvec and migration so the migration failure could cause contiguous memory allocation failure in the end. To close the race, this patch disables lru caches(i.e, pagevec) during ongoing migration until migrate is done. Since it's really hard to reproduce, I measured how many times migrate_pages retried with force mode below debug code. int migrate_pages(struct list_head *from, new_page_t get_new_page, .. .. if (rc && reason == MR_CONTIG_RANGE && pass > 2) { printk(KERN_ERR, "pfn 0x%lx reason %d\n", page_to_pfn(page), rc); dump_page(page, "fail to migrate"); } The test was repeating android apps launching with cma allocation in background every five seconds. Total cma allocation count was about 500 during the testing. With this patch, the dump_page count was reduced from 400 to 30. Signed-off-by: Minchan Kim --- * from RFC - http://lore.kernel.org/linux-mm/20210216170348.1513483-1-minchan@kernel.org * use atomic and lru_add_drain_all for strict ordering - mhocko * lru_cache_disable/enable - mhocko fs/block_dev.c | 2 +- include/linux/migrate.h | 6 +++-- include/linux/swap.h | 4 ++- mm/compaction.c | 4 +-- mm/fadvise.c | 2 +- mm/gup.c | 2 +- mm/khugepaged.c | 2 +- mm/ksm.c | 2 +- mm/memcontrol.c | 4 +-- mm/memfd.c | 2 +- mm/memory-failure.c | 2 +- mm/memory_hotplug.c | 2 +- mm/mempolicy.c | 6 +++++ mm/migrate.c | 15 ++++++----- mm/page_alloc.c | 5 +++- mm/swap.c | 55 +++++++++++++++++++++++++++++++++++------ 16 files changed, 85 insertions(+), 30 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index 7a814a13f9a4..1fe75dbd0ce0 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -93,7 +93,7 @@ void invalidate_bdev(struct block_device *bdev) if (mapping->nrpages) { invalidate_bh_lrus(); - lru_add_drain_all(); /* make sure all lru add caches are flushed */ + lru_add_drain_all(false); /* make sure all lru add caches are flushed */ invalidate_mapping_pages(mapping, 0, -1); } /* 99% of the time, we don't need to flush the cleancache on the bdev. diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 3a389633b68f..6a23174ea081 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -47,6 +47,7 @@ extern void putback_movable_page(struct page *page); extern void migrate_prep(void); extern void migrate_prep_local(void); +extern void migrate_finish(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, @@ -66,8 +67,9 @@ 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_prep(void) { return -ENOSYS; } +static inline void migrate_prep_local(void) { return -ENOSYS; } +static inline void migrate_done(void) {} static inline void migrate_page_states(struct page *newpage, struct page *page) { diff --git a/include/linux/swap.h b/include/linux/swap.h index 71166bc10d17..8ab7ad7157f3 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -339,10 +339,12 @@ extern void lru_note_cost(struct lruvec *lruvec, bool file, extern void lru_note_cost_page(struct page *); extern void lru_cache_add(struct page *); extern void mark_page_accessed(struct page *); +extern void lru_cache_disable(void); +extern void lru_cache_enable(void); extern void lru_add_drain(void); extern void lru_add_drain_cpu(int cpu); extern void lru_add_drain_cpu_zone(struct zone *zone); -extern void lru_add_drain_all(void); +extern void lru_add_drain_all(bool force_all_cpus); extern void rotate_reclaimable_page(struct page *page); extern void deactivate_file_page(struct page *page); extern void deactivate_page(struct page *page); diff --git a/mm/compaction.c b/mm/compaction.c index 50b31e2ec6cb..519f6c241e69 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -2648,7 +2648,7 @@ static void compact_nodes(void) int nid; /* Flush pending updates to the LRU lists */ - lru_add_drain_all(); + lru_add_drain_all(false); for_each_online_node(nid) compact_node(nid); @@ -2686,7 +2686,7 @@ static ssize_t sysfs_compact_node(struct device *dev, if (nid >= 0 && nid < nr_node_ids && node_online(nid)) { /* Flush pending updates to the LRU lists */ - lru_add_drain_all(); + lru_add_drain_all(false); compact_node(nid); } diff --git a/mm/fadvise.c b/mm/fadvise.c index d6baa4f451c5..6053cd878b18 100644 --- a/mm/fadvise.c +++ b/mm/fadvise.c @@ -165,7 +165,7 @@ int generic_fadvise(struct file *file, loff_t offset, loff_t len, int advice) * pagevecs and try again. */ if (nr_pagevec) { - lru_add_drain_all(); + lru_add_drain_all(false); invalidate_mapping_pages(mapping, start_index, end_index); } diff --git a/mm/gup.c b/mm/gup.c index 3e086b073624..2d51edd1601b 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1586,7 +1586,7 @@ static long check_and_migrate_cma_pages(struct mm_struct *mm, isolate_huge_page(head, &cma_page_list); else { if (!PageLRU(head) && drain_allow) { - lru_add_drain_all(); + lru_add_drain_all(false); drain_allow = false; } diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 8369d9620f6d..65d08a35be08 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -2211,7 +2211,7 @@ static void khugepaged_do_scan(void) barrier(); /* write khugepaged_pages_to_scan to local stack */ - lru_add_drain_all(); + lru_add_drain_all(false); while (progress < pages) { if (!khugepaged_prealloc_page(&hpage, &wait)) diff --git a/mm/ksm.c b/mm/ksm.c index 9694ee2c71de..3559e2c92ebf 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -2245,7 +2245,7 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page) * them here (here rather than on entry to ksm_do_scan(), * so we don't IPI too often when pages_to_scan is set low). */ - lru_add_drain_all(); + lru_add_drain_all(false); /* * Whereas stale stable_nodes on the stable_tree itself diff --git a/mm/memcontrol.c b/mm/memcontrol.c index ed5cc78a8dbf..12f70487915e 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3520,7 +3520,7 @@ static int mem_cgroup_force_empty(struct mem_cgroup *memcg) int nr_retries = MAX_RECLAIM_RETRIES; /* we call try-to-free pages for make this cgroup empty */ - lru_add_drain_all(); + lru_add_drain_all(false); drain_all_stock(memcg); @@ -6140,7 +6140,7 @@ static const struct mm_walk_ops charge_walk_ops = { static void mem_cgroup_move_charge(void) { - lru_add_drain_all(); + lru_add_drain_all(false); /* * Signal lock_page_memcg() to take the memcg's move_lock * while we're moving its pages to another memcg. Then wait diff --git a/mm/memfd.c b/mm/memfd.c index 2647c898990c..79d6e004a89b 100644 --- a/mm/memfd.c +++ b/mm/memfd.c @@ -79,7 +79,7 @@ static int memfd_wait_for_pins(struct address_space *mapping) break; if (!scan) - lru_add_drain_all(); + lru_add_drain_all(false); else if (schedule_timeout_killable((HZ << scan) / 200)) scan = LAST_SCAN; diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 4e3684d694c1..aba281dc58d7 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -272,7 +272,7 @@ void shake_page(struct page *p, int access) return; if (!PageSlab(p)) { - lru_add_drain_all(); + lru_add_drain_all(false); if (PageLRU(p) || is_free_buddy_page(p)) return; } diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index a969463bdda4..56d224e8e7f6 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1602,7 +1602,7 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages) } cond_resched(); - lru_add_drain_all(); + lru_add_drain_all(false); ret = scan_movable_pages(pfn, end_pfn, &pfn); if (!ret) { diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 6961238c7ef5..46d9986c7bf0 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1208,6 +1208,8 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, break; } mmap_read_unlock(mm); + migrate_finish(); + if (err < 0) return err; return busy; @@ -1371,6 +1373,10 @@ static long do_mbind(unsigned long start, unsigned long len, mmap_write_unlock(mm); mpol_out: mpol_put(new); + + if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) + migrate_finish(); + return err; } diff --git a/mm/migrate.c b/mm/migrate.c index a69da8aaeccd..bcf4637f6950 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -65,12 +65,9 @@ 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. + * Clear the LRU pcp lists so pages can be isolated. */ - lru_add_drain_all(); + lru_cache_disable(); } /* Do the necessary work of migrate_prep but not if it involves other CPUs */ @@ -79,6 +76,11 @@ void migrate_prep_local(void) lru_add_drain(); } +void migrate_finish(void) +{ + lru_cache_enable(); +} + int isolate_movable_page(struct page *page, isolate_mode_t mode) { struct address_space *mapping; @@ -1837,6 +1839,7 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, if (err >= 0) err = err1; out: + migrate_finish(); return err; } @@ -2673,7 +2676,7 @@ static void migrate_vma_prepare(struct migrate_vma *migrate) if (!is_zone_device_page(page)) { if (!PageLRU(page) && allow_drain) { /* Drain CPU's pagevec */ - lru_add_drain_all(); + lru_add_drain_all(false); allow_drain = false; } diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6446778cbc6b..9214fdada691 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8493,6 +8493,9 @@ static int __alloc_contig_migrate_range(struct compact_control *cc, ret = migrate_pages(&cc->migratepages, alloc_migration_target, NULL, (unsigned long)&mtc, cc->mode, MR_CONTIG_RANGE); } + + migrate_finish(); + if (ret < 0) { putback_movable_pages(&cc->migratepages); return ret; @@ -8603,7 +8606,7 @@ int alloc_contig_range(unsigned long start, unsigned long end, * isolated thus they won't get removed from buddy. */ - lru_add_drain_all(); + lru_add_drain_all(false); order = 0; outer_start = start; diff --git a/mm/swap.c b/mm/swap.c index 31b844d4ed94..c1fa6cac04c1 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -54,6 +54,32 @@ static DEFINE_PER_CPU(struct lru_rotate, lru_rotate) = { .lock = INIT_LOCAL_LOCK(lock), }; +static atomic_t lru_disable_count = ATOMIC_INIT(0); + +bool lru_cache_disabled(void) +{ + return atomic_read(&lru_disable_count); +} + +void lru_cache_disable(void) +{ + /* + * lru_add_drain_all's IPI will make sure no new pages are added + * to the pcp lists and drain them all. + */ + atomic_inc(&lru_disable_count); + + /* + * Clear the LRU lists so pages can be isolated. + */ + lru_add_drain_all(true); +} + +void lru_cache_enable(void) +{ + atomic_dec(&lru_disable_count); +} + /* * The following struct pagevec are grouped together because they are protected * by disabling preemption (and interrupts remain enabled). @@ -235,6 +261,18 @@ static void pagevec_move_tail_fn(struct page *page, struct lruvec *lruvec) } } +/* return true if pagevec needs to drain */ +static bool pagevec_add_and_need_flush(struct pagevec *pvec, struct page *page) +{ + bool ret = false; + + if (!pagevec_add(pvec, page) || PageCompound(page) || + lru_cache_disabled()) + ret = true; + + return ret; +} + /* * Writeback is about to end against a page which has been marked for immediate * reclaim. If it still appears to be reclaimable, move it to the tail of the @@ -252,7 +290,7 @@ void rotate_reclaimable_page(struct page *page) get_page(page); local_lock_irqsave(&lru_rotate.lock, flags); pvec = this_cpu_ptr(&lru_rotate.pvec); - if (!pagevec_add(pvec, page) || PageCompound(page)) + if (pagevec_add_and_need_flush(pvec, page)) pagevec_lru_move_fn(pvec, pagevec_move_tail_fn); local_unlock_irqrestore(&lru_rotate.lock, flags); } @@ -343,7 +381,7 @@ static void activate_page(struct page *page) local_lock(&lru_pvecs.lock); pvec = this_cpu_ptr(&lru_pvecs.activate_page); get_page(page); - if (!pagevec_add(pvec, page) || PageCompound(page)) + if (pagevec_add_and_need_flush(pvec, page)) pagevec_lru_move_fn(pvec, __activate_page); local_unlock(&lru_pvecs.lock); } @@ -458,7 +496,7 @@ void lru_cache_add(struct page *page) get_page(page); local_lock(&lru_pvecs.lock); pvec = this_cpu_ptr(&lru_pvecs.lru_add); - if (!pagevec_add(pvec, page) || PageCompound(page)) + if (pagevec_add_and_need_flush(pvec, page)) __pagevec_lru_add(pvec); local_unlock(&lru_pvecs.lock); } @@ -654,7 +692,7 @@ void deactivate_file_page(struct page *page) local_lock(&lru_pvecs.lock); pvec = this_cpu_ptr(&lru_pvecs.lru_deactivate_file); - if (!pagevec_add(pvec, page) || PageCompound(page)) + if (pagevec_add_and_need_flush(pvec, page)) pagevec_lru_move_fn(pvec, lru_deactivate_file_fn); local_unlock(&lru_pvecs.lock); } @@ -676,7 +714,7 @@ void deactivate_page(struct page *page) local_lock(&lru_pvecs.lock); pvec = this_cpu_ptr(&lru_pvecs.lru_deactivate); get_page(page); - if (!pagevec_add(pvec, page) || PageCompound(page)) + if (pagevec_add_and_need_flush(pvec, page)) pagevec_lru_move_fn(pvec, lru_deactivate_fn); local_unlock(&lru_pvecs.lock); } @@ -698,7 +736,7 @@ void mark_page_lazyfree(struct page *page) local_lock(&lru_pvecs.lock); pvec = this_cpu_ptr(&lru_pvecs.lru_lazyfree); get_page(page); - if (!pagevec_add(pvec, page) || PageCompound(page)) + if (pagevec_add_and_need_flush(pvec, page)) pagevec_lru_move_fn(pvec, lru_lazyfree_fn); local_unlock(&lru_pvecs.lock); } @@ -735,7 +773,7 @@ static void lru_add_drain_per_cpu(struct work_struct *dummy) * Calling this function with cpu hotplug locks held can actually lead * to obscure indirect dependencies via WQ context. */ -void lru_add_drain_all(void) +void lru_add_drain_all(bool force_all_cpus) { /* * lru_drain_gen - Global pages generation number @@ -810,7 +848,8 @@ void lru_add_drain_all(void) for_each_online_cpu(cpu) { struct work_struct *work = &per_cpu(lru_add_drain_work, cpu); - if (pagevec_count(&per_cpu(lru_pvecs.lru_add, cpu)) || + if (force_all_cpus || + pagevec_count(&per_cpu(lru_pvecs.lru_add, cpu)) || data_race(pagevec_count(&per_cpu(lru_rotate.pvec, cpu))) || pagevec_count(&per_cpu(lru_pvecs.lru_deactivate_file, cpu)) || pagevec_count(&per_cpu(lru_pvecs.lru_deactivate, cpu)) || From patchwork Tue Mar 2 21:09:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Minchan Kim X-Patchwork-Id: 12112929 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,URIBL_BLOCKED,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 F3CBFC43332 for ; Wed, 3 Mar 2021 05:38:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA07764EBB for ; Wed, 3 Mar 2021 05:38:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1450140AbhCCFai (ORCPT ); Wed, 3 Mar 2021 00:30:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1383538AbhCBVOx (ORCPT ); Tue, 2 Mar 2021 16:14:53 -0500 Received: from mail-pf1-x42e.google.com (mail-pf1-x42e.google.com [IPv6:2607:f8b0:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C226AC06178A; Tue, 2 Mar 2021 13:09:57 -0800 (PST) Received: by mail-pf1-x42e.google.com with SMTP id r5so14610978pfh.13; Tue, 02 Mar 2021 13:09:57 -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:in-reply-to:references :mime-version:content-transfer-encoding; bh=jLiR8SYAwchy/DlkrlFgQINPVuwrI0Zg692gmaFjw9k=; b=IFUIGqHBTNScTiFWkuY1Ib52OJbHgxUGyzy4qh3Hq9QqhdV+ogJkK7cASh6bZFGKwL KvsyArkHNDF1xOobPTIr2kYpT8c7Jx/+o/tkcwbLOF/2fVdJ94ANDy2FUoXgP9tWkWRk Mizp3N22UKXAfHWdJz6B4n1jrDa75X9LxHlKJgs5eO7LgqXa0Jc5s5rgMh3EeGl+8ue0 WOwLGSz+zqvn967hfe4ckjNQrqV3aNifobgpqUU1y3TVJdbWc1oq4k/qBFw2DUHYREHJ 3vVZrDA9AZKBlzEjuOHxDxw8uvLWxGL7y3Gt2NK5JxlKRp8eSD/h2EbMJKPX6rRfHtE8 LKNg== 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 :in-reply-to:references:mime-version:content-transfer-encoding; bh=jLiR8SYAwchy/DlkrlFgQINPVuwrI0Zg692gmaFjw9k=; b=J5lSWYHKWwfzmu1Bh2KphvZ2cBDtSSe3uVbq+KlzUSN2G8GVebTe54Z1Rc7MeWyw5j RGmpBzuJQyN3CD621zhwLmlWhSv367PmhiYTDlXmnuTPn3zQ2+q6kV+3pugPwjOK0Uwb qLjb+vk/6U62saD4qZgcAvd1dQW2o0/Rr5DkIBOE+MtjgpWoBPWAu70Rn3vMPnpTUlam Z4Ym2ddYzkeAzR4ZFJU9J2yhFJ//dnqc8RJz9KUE/M9yTaEzi3WAS7IBJrx+F9xp0Xjc jZr4UNwkxDKL/7fQ5Hi9DWNL0QMuK25EyhiZQF6A1AAqd4buN1N6QajuZc5zFjq55IZZ 8CIA== X-Gm-Message-State: AOAM530aGeeGdIgfFezTGl3N/gmygM5OpGaU9i3a6tWOHKN+ep31J1Oe JQp5L5KaCryOYU24XsKoGfY= X-Google-Smtp-Source: ABdhPJyoEpfHvAYdphZemlUp2UGkVZwJFiTtdWwCsElybLHA9mtTJbCa0aFYiWgzREV6DGTI0ts9hw== X-Received: by 2002:a62:aa02:0:b029:1ee:3011:114e with SMTP id e2-20020a62aa020000b02901ee3011114emr2306pff.39.1614719396845; Tue, 02 Mar 2021 13:09:56 -0800 (PST) Received: from bbox-1.mtv.corp.google.com ([2620:15c:211:201:c87:c34:99dc:ba23]) by smtp.gmail.com with ESMTPSA id w17sm18980572pgg.41.2021.03.02.13.09.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 02 Mar 2021 13:09:55 -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 2/2] mm: fs: Invalidate BH LRU during page migration Date: Tue, 2 Mar 2021 13:09:49 -0800 Message-Id: <20210302210949.2440120-2-minchan@kernel.org> X-Mailer: git-send-email 2.30.1.766.gb4fecdf3b7-goog In-Reply-To: <20210302210949.2440120-1-minchan@kernel.org> References: <20210302210949.2440120-1-minchan@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Pages containing buffer_heads that are in one of the per-CPU buffer_head LRU caches will be pinned and thus cannot be migrated. This can prevent CMA allocations from succeeding, which are often used on platforms with co-processors (such as a DSP) that can only use physically contiguous memory. It can also prevent memory hot-unplugging from succeeding, which involves migrating at least MIN_MEMORY_BLOCK_SIZE bytes of memory, which ranges from 8 MiB to 1 GiB based on the architecture in use. Correspondingly, invalidate the BH LRU caches before a migration starts and stop any buffer_head from being cached in the LRU caches, until migration has finished. Suggested-by: Matthew Wilcox Signed-off-by: Chris Goldsworthy Signed-off-by: Minchan Kim --- * from prev - https://lore.kernel.org/linux-mm/e8f3e042b902156467a5e978b57c14954213ec59.1611642039.git.cgoldswo@codeaurora.org/ * consolidate bh_lru drain logic into lru pagevec - willy fs/buffer.c | 12 ++++++++++-- include/linux/buffer_head.h | 2 ++ include/linux/swap.h | 1 + mm/swap.c | 5 ++++- 4 files changed, 17 insertions(+), 3 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index 96c7604f69b3..4492e9d4c9d3 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1301,6 +1301,14 @@ static void bh_lru_install(struct buffer_head *bh) int i; check_irqs_on(); + /* + * buffer_head in bh_lru could increase refcount of the page + * until it will be invalidated. It causes page migraion failure. + * Skip putting upcoming bh into bh_lru until migration is done. + */ + if (lru_cache_disabled()) + return; + bh_lru_lock(); b = this_cpu_ptr(&bh_lrus); @@ -1446,7 +1454,7 @@ EXPORT_SYMBOL(__bread_gfp); * This doesn't race because it runs in each cpu either in irq * or with preempt disabled. */ -static void invalidate_bh_lru(void *arg) +void invalidate_bh_lru(void *arg) { struct bh_lru *b = &get_cpu_var(bh_lrus); int i; @@ -1458,7 +1466,7 @@ static void invalidate_bh_lru(void *arg) put_cpu_var(bh_lrus); } -static bool has_bh_in_lru(int cpu, void *dummy) +bool has_bh_in_lru(int cpu, void *dummy) { struct bh_lru *b = per_cpu_ptr(&bh_lrus, cpu); int i; diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 6b47f94378c5..3d98bdabaac9 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -194,6 +194,8 @@ void __breadahead_gfp(struct block_device *, sector_t block, unsigned int size, struct buffer_head *__bread_gfp(struct block_device *, sector_t block, unsigned size, gfp_t gfp); void invalidate_bh_lrus(void); +void invalidate_bh_lru(void *); +bool has_bh_in_lru(int cpu, void *dummy); struct buffer_head *alloc_buffer_head(gfp_t gfp_flags); void free_buffer_head(struct buffer_head * bh); void unlock_buffer(struct buffer_head *bh); diff --git a/include/linux/swap.h b/include/linux/swap.h index 8ab7ad7157f3..94a77e618dba 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -341,6 +341,7 @@ extern void lru_cache_add(struct page *); extern void mark_page_accessed(struct page *); extern void lru_cache_disable(void); extern void lru_cache_enable(void); +extern bool lru_cache_disabled(void); extern void lru_add_drain(void); extern void lru_add_drain_cpu(int cpu); extern void lru_add_drain_cpu_zone(struct zone *zone); diff --git a/mm/swap.c b/mm/swap.c index c1fa6cac04c1..88d51b9ebc8c 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -36,6 +36,7 @@ #include #include #include +#include #include "internal.h" @@ -667,6 +668,7 @@ void lru_add_drain_cpu(int cpu) pagevec_lru_move_fn(pvec, lru_lazyfree_fn); activate_page_drain(cpu); + invalidate_bh_lru(NULL); } /** @@ -854,7 +856,8 @@ void lru_add_drain_all(bool force_all_cpus) pagevec_count(&per_cpu(lru_pvecs.lru_deactivate_file, cpu)) || pagevec_count(&per_cpu(lru_pvecs.lru_deactivate, cpu)) || pagevec_count(&per_cpu(lru_pvecs.lru_lazyfree, cpu)) || - need_activate_page_drain(cpu)) { + need_activate_page_drain(cpu) || + has_bh_in_lru(cpu, NULL)) { INIT_WORK(work, lru_add_drain_per_cpu); queue_work_on(cpu, mm_percpu_wq, work); __cpumask_set_cpu(cpu, &has_work);