From mboxrd@z Thu Jan 1 00:00:00 1970 From: Muchun Song Subject: [PATCH v6 05/11] mm: vmscan: rework move_pages_to_lru() Date: Tue, 21 Jun 2022 20:56:52 +0800 Message-ID: <20220621125658.64935-6-songmuchun@bytedance.com> References: <20220621125658.64935-1-songmuchun@bytedance.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=JQmNu1Pi61kiVMPJr8aGyJU8VoXoYJEPNAmwcIY/MLE=; b=uRoZYgA2WDdO9ticBdRw4R7/aUXk5r9fqjKxKJCs1SkEG4UdxhjFsO/X/PheSrZDg+ Q23F5hcZd9t0a7k63chGSWb3GHjtfCKitwmgpkZIMzFXmeCoTtJZt1WI45hmjAbSNvjU /5wRPFqGLSXBhc/RogtGwjV9RN90CBGRxKIoHDUJysh3Wr6Y4yJWuUtBVejjCQihuCj0 CtlKQVvYF4ukD9CjCMcdRjlepscIFcl4DKR7BS4rzRSK7Mf6uRzcc1U6qlPUu8rUerNI JY12moVGemqnvgCfDy9ZpJmjCyPFcuQ5O6SQvqUei19rSVIpmLCFjVox8NrK4WND0BYX Cqsg== In-Reply-To: <20220621125658.64935-1-songmuchun-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" To: akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, roman.gushchin-fxUVXftIFDnyG1zEObXtfA@public.gmane.org, shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, duanxiongchun-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Muchun Song In the later patch, we will reparent the LRU pages. The pages moved to appropriate LRU list can be reparented during the process of the move_pages_to_lru(). So holding a lruvec lock by the caller is wrong, we should use the more general interface of folio_lruvec_relock_irq() to acquire the correct lruvec lock. Signed-off-by: Muchun Song Acked-by: Johannes Weiner Acked-by: Roman Gushchin --- mm/vmscan.c | 39 +++++++++++++++++++-------------------- 1 file changed, 19 insertions(+), 20 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 6a554712ef5d..697656151431 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2312,23 +2312,26 @@ static int too_many_isolated(struct pglist_data *pgdat, int file, * move_pages_to_lru() moves folios from private @list to appropriate LRU list. * On return, @list is reused as a list of folios to be freed by the caller. * - * Returns the number of pages moved to the given lruvec. + * Returns the number of pages moved to the appropriate LRU list. + * + * Note: The caller must not hold any lruvec lock. */ -static unsigned int move_pages_to_lru(struct lruvec *lruvec, - struct list_head *list) +static unsigned int move_pages_to_lru(struct list_head *list) { int nr_pages, nr_moved = 0; + struct lruvec *lruvec = NULL; LIST_HEAD(folios_to_free); while (!list_empty(list)) { struct folio *folio = lru_to_folio(list); + lruvec = folio_lruvec_relock_irq(folio, lruvec); VM_BUG_ON_FOLIO(folio_test_lru(folio), folio); list_del(&folio->lru); if (unlikely(!folio_evictable(folio))) { - spin_unlock_irq(&lruvec->lru_lock); + lruvec_unlock_irq(lruvec); folio_putback_lru(folio); - spin_lock_irq(&lruvec->lru_lock); + lruvec = NULL; continue; } @@ -2349,19 +2352,15 @@ static unsigned int move_pages_to_lru(struct lruvec *lruvec, __folio_clear_lru_flags(folio); if (unlikely(folio_test_large(folio))) { - spin_unlock_irq(&lruvec->lru_lock); + lruvec_unlock_irq(lruvec); destroy_large_folio(folio); - spin_lock_irq(&lruvec->lru_lock); + lruvec = NULL; } else list_add(&folio->lru, &folios_to_free); continue; } - /* - * All pages were isolated from the same lruvec (and isolation - * inhibits memcg migration). - */ VM_BUG_ON_FOLIO(!folio_matches_lruvec(folio, lruvec), folio); lruvec_add_folio(lruvec, folio); nr_pages = folio_nr_pages(folio); @@ -2370,6 +2369,8 @@ static unsigned int move_pages_to_lru(struct lruvec *lruvec, workingset_age_nonresident(lruvec, nr_pages); } + if (lruvec) + lruvec_unlock_irq(lruvec); /* * To save our caller's stack, now use input list for pages to free. */ @@ -2440,16 +2441,16 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, nr_reclaimed = shrink_page_list(&page_list, pgdat, sc, &stat, false); - spin_lock_irq(&lruvec->lru_lock); - move_pages_to_lru(lruvec, &page_list); + move_pages_to_lru(&page_list); + local_irq_disable(); __mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, -nr_taken); item = current_is_kswapd() ? PGSTEAL_KSWAPD : PGSTEAL_DIRECT; if (!cgroup_reclaim(sc)) __count_vm_events(item, nr_reclaimed); __count_memcg_events(lruvec_memcg(lruvec), item, nr_reclaimed); __count_vm_events(PGSTEAL_ANON + file, nr_reclaimed); - spin_unlock_irq(&lruvec->lru_lock); + local_irq_enable(); lru_note_cost(lruvec, file, stat.nr_pageout); mem_cgroup_uncharge_list(&page_list); @@ -2578,18 +2579,16 @@ static void shrink_active_list(unsigned long nr_to_scan, /* * Move folios back to the lru list. */ - spin_lock_irq(&lruvec->lru_lock); - - nr_activate = move_pages_to_lru(lruvec, &l_active); - nr_deactivate = move_pages_to_lru(lruvec, &l_inactive); + nr_activate = move_pages_to_lru(&l_active); + nr_deactivate = move_pages_to_lru(&l_inactive); /* Keep all free folios in l_active list */ list_splice(&l_inactive, &l_active); + local_irq_disable(); __count_vm_events(PGDEACTIVATE, nr_deactivate); __count_memcg_events(lruvec_memcg(lruvec), PGDEACTIVATE, nr_deactivate); - __mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, -nr_taken); - spin_unlock_irq(&lruvec->lru_lock); + local_irq_enable(); mem_cgroup_uncharge_list(&l_active); free_unref_page_list(&l_active); -- 2.11.0