From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx166.postini.com [74.125.245.166]) by kanga.kvack.org (Postfix) with SMTP id E695D6B0005 for ; Tue, 9 Apr 2013 03:20:10 -0400 (EDT) Received: from /spool/local by e28smtp05.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 9 Apr 2013 12:46:55 +0530 Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id 333CA125804F for ; Tue, 9 Apr 2013 12:51:28 +0530 (IST) Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay03.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r397Jvc47012692 for ; Tue, 9 Apr 2013 12:49:58 +0530 Received: from d28av01.in.ibm.com (loopback [127.0.0.1]) by d28av01.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r397K2PN009557 for ; Tue, 9 Apr 2013 07:20:03 GMT Date: Tue, 9 Apr 2013 15:19:59 +0800 From: Wanpeng Li Subject: Re: [PATCH 1/3] mm, vmscan: count accidental reclaimed pages failed to put into lru Message-ID: <20130409071959.GA30316@hacker.(null)> Reply-To: Wanpeng Li References: <1365470478-645-1-git-send-email-iamjoonsoo.kim@lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1365470478-645-1-git-send-email-iamjoonsoo.kim@lge.com> Sender: owner-linux-mm@kvack.org List-ID: To: Joonsoo Kim Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Mel Gorman , Hugh Dickins , Rik van Riel , Minchan Kim On Tue, Apr 09, 2013 at 10:21:16AM +0900, Joonsoo Kim wrote: >In shrink_(in)active_list(), we can fail to put into lru, and these pages >are reclaimed accidentally. Currently, these pages are not counted >for sc->nr_reclaimed, but with this information, we can stop to reclaim >earlier, so can reduce overhead of reclaim. > Great Catch! Regards, Wanpeng Li >Signed-off-by: Joonsoo Kim > >diff --git a/include/linux/gfp.h b/include/linux/gfp.h >index 0f615eb..5d60ae0 100644 >--- a/include/linux/gfp.h >+++ b/include/linux/gfp.h >@@ -365,7 +365,7 @@ void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask); > extern void __free_pages(struct page *page, unsigned int order); > extern void free_pages(unsigned long addr, unsigned int order); > extern void free_hot_cold_page(struct page *page, int cold); >-extern void free_hot_cold_page_list(struct list_head *list, int cold); >+extern unsigned long free_hot_cold_page_list(struct list_head *list, int cold); > > extern void __free_memcg_kmem_pages(struct page *page, unsigned int order); > extern void free_memcg_kmem_pages(unsigned long addr, unsigned int order); >diff --git a/mm/page_alloc.c b/mm/page_alloc.c >index 8fcced7..a5f3952 100644 >--- a/mm/page_alloc.c >+++ b/mm/page_alloc.c >@@ -1360,14 +1360,18 @@ out: > /* > * Free a list of 0-order pages > */ >-void free_hot_cold_page_list(struct list_head *list, int cold) >+unsigned long free_hot_cold_page_list(struct list_head *list, int cold) > { >+ unsigned long nr_reclaimed = 0; > struct page *page, *next; > > list_for_each_entry_safe(page, next, list, lru) { > trace_mm_page_free_batched(page, cold); > free_hot_cold_page(page, cold); >+ nr_reclaimed++; > } >+ >+ return nr_reclaimed; > } > > /* >diff --git a/mm/vmscan.c b/mm/vmscan.c >index 88c5fed..eff2927 100644 >--- a/mm/vmscan.c >+++ b/mm/vmscan.c >@@ -915,7 +915,6 @@ static unsigned long shrink_page_list(struct list_head *page_list, > */ > __clear_page_locked(page); > free_it: >- nr_reclaimed++; > > /* > * Is there need to periodically free_page_list? It would >@@ -954,7 +953,7 @@ keep: > if (nr_dirty && nr_dirty == nr_congested && global_reclaim(sc)) > zone_set_flag(zone, ZONE_CONGESTED); > >- free_hot_cold_page_list(&free_pages, 1); >+ nr_reclaimed += free_hot_cold_page_list(&free_pages, 1); > > list_splice(&ret_pages, page_list); > count_vm_events(PGACTIVATE, pgactivate); >@@ -1321,7 +1320,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, > if (nr_taken == 0) > return 0; > >- nr_reclaimed = shrink_page_list(&page_list, zone, sc, TTU_UNMAP, >+ nr_reclaimed += shrink_page_list(&page_list, zone, sc, TTU_UNMAP, > &nr_dirty, &nr_writeback, false); > > spin_lock_irq(&zone->lru_lock); >@@ -1343,7 +1342,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, > > spin_unlock_irq(&zone->lru_lock); > >- free_hot_cold_page_list(&page_list, 1); >+ nr_reclaimed += free_hot_cold_page_list(&page_list, 1); > > /* > * If reclaim is isolating dirty pages under writeback, it implies >@@ -1438,7 +1437,7 @@ static void move_active_pages_to_lru(struct lruvec *lruvec, > __count_vm_events(PGDEACTIVATE, pgmoved); > } > >-static void shrink_active_list(unsigned long nr_to_scan, >+static unsigned long shrink_active_list(unsigned long nr_to_scan, > struct lruvec *lruvec, > struct scan_control *sc, > enum lru_list lru) >@@ -1534,7 +1533,7 @@ static void shrink_active_list(unsigned long nr_to_scan, > __mod_zone_page_state(zone, NR_ISOLATED_ANON + file, -nr_taken); > spin_unlock_irq(&zone->lru_lock); > >- free_hot_cold_page_list(&l_hold, 1); >+ return free_hot_cold_page_list(&l_hold, 1); > } > > #ifdef CONFIG_SWAP >@@ -1617,7 +1616,8 @@ static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan, > { > if (is_active_lru(lru)) { > if (inactive_list_is_low(lruvec, lru)) >- shrink_active_list(nr_to_scan, lruvec, sc, lru); >+ return shrink_active_list(nr_to_scan, lruvec, sc, lru); >+ > return 0; > } > >@@ -1861,8 +1861,8 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc) > * rebalance the anon lru active/inactive ratio. > */ > if (inactive_anon_is_low(lruvec)) >- shrink_active_list(SWAP_CLUSTER_MAX, lruvec, >- sc, LRU_ACTIVE_ANON); >+ sc->nr_reclaimed += shrink_active_list(SWAP_CLUSTER_MAX, >+ lruvec, sc, LRU_ACTIVE_ANON); > > throttle_vm_writeout(sc->gfp_mask); > } >@@ -2470,23 +2470,27 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, > } > #endif > >-static void age_active_anon(struct zone *zone, struct scan_control *sc) >+static unsigned long age_active_anon(struct zone *zone, >+ struct scan_control *sc) > { >+ unsigned long nr_reclaimed = 0; > struct mem_cgroup *memcg; > > if (!total_swap_pages) >- return; >+ return 0; > > memcg = mem_cgroup_iter(NULL, NULL, NULL); > do { > struct lruvec *lruvec = mem_cgroup_zone_lruvec(zone, memcg); > > if (inactive_anon_is_low(lruvec)) >- shrink_active_list(SWAP_CLUSTER_MAX, lruvec, >- sc, LRU_ACTIVE_ANON); >+ nr_reclaimed += shrink_active_list(SWAP_CLUSTER_MAX, >+ lruvec, sc, LRU_ACTIVE_ANON); > > memcg = mem_cgroup_iter(NULL, memcg, NULL); > } while (memcg); >+ >+ return nr_reclaimed; > } > > static bool zone_balanced(struct zone *zone, int order, >@@ -2666,7 +2670,7 @@ loop_again: > * Do some background aging of the anon list, to give > * pages a chance to be referenced before reclaiming. > */ >- age_active_anon(zone, &sc); >+ sc.nr_reclaimed += age_active_anon(zone, &sc); > > /* > * If the number of buffer_heads in the machine >-- >1.7.9.5 > >-- >To unsubscribe, send a message with 'unsubscribe linux-mm' in >the body to majordomo@kvack.org. For more info on Linux MM, >see: http://www.linux-mm.org/ . >Don't email: email@kvack.org -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org