From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752079AbcL2FeD (ORCPT ); Thu, 29 Dec 2016 00:34:03 -0500 Received: from LGEAMRELO12.lge.com ([156.147.23.52]:35668 "EHLO lgeamrelo12.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751158AbcL2FeC (ORCPT ); Thu, 29 Dec 2016 00:34:02 -0500 X-Original-SENDERIP: 156.147.1.126 X-Original-MAILFROM: minchan@kernel.org X-Original-SENDERIP: 10.177.223.161 X-Original-MAILFROM: minchan@kernel.org Date: Thu, 29 Dec 2016 14:33:59 +0900 From: Minchan Kim To: Michal Hocko Cc: linux-mm@kvack.org, Andrew Morton , Mel Gorman , Johannes Weiner , Vlastimil Babka , Rik van Riel , LKML , Michal Hocko Subject: Re: [PATCH 2/7] mm, vmscan: add active list aging tracepoint Message-ID: <20161229053359.GA1815@bbox> References: <20161228153032.10821-1-mhocko@kernel.org> <20161228153032.10821-3-mhocko@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161228153032.10821-3-mhocko@kernel.org> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 28, 2016 at 04:30:27PM +0100, Michal Hocko wrote: > From: Michal Hocko > > Our reclaim process has several tracepoints to tell us more about how > things are progressing. We are, however, missing a tracepoint to track > active list aging. Introduce mm_vmscan_lru_shrink_active which reports > the number of scanned, rotated, deactivated and freed pages from the > particular node's active list. > > Signed-off-by: Michal Hocko > --- > include/linux/gfp.h | 2 +- > include/trace/events/vmscan.h | 38 ++++++++++++++++++++++++++++++++++++++ > mm/page_alloc.c | 6 +++++- > mm/vmscan.c | 22 +++++++++++++++++----- > 4 files changed, 61 insertions(+), 7 deletions(-) > > diff --git a/include/linux/gfp.h b/include/linux/gfp.h > index 4175dca4ac39..61aa9b49e86d 100644 > --- a/include/linux/gfp.h > +++ b/include/linux/gfp.h > @@ -503,7 +503,7 @@ void * __meminit 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, bool cold); > -extern void free_hot_cold_page_list(struct list_head *list, bool cold); > +extern int free_hot_cold_page_list(struct list_head *list, bool cold); > > struct page_frag_cache; > extern void __page_frag_drain(struct page *page, unsigned int order, > diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h > index 39bad8921ca1..d34cc0ced2be 100644 > --- a/include/trace/events/vmscan.h > +++ b/include/trace/events/vmscan.h > @@ -363,6 +363,44 @@ TRACE_EVENT(mm_vmscan_lru_shrink_inactive, > show_reclaim_flags(__entry->reclaim_flags)) > ); > > +TRACE_EVENT(mm_vmscan_lru_shrink_active, > + > + TP_PROTO(int nid, unsigned long nr_scanned, unsigned long nr_freed, > + unsigned long nr_unevictable, unsigned long nr_deactivated, > + unsigned long nr_rotated, int priority, int file), > + > + TP_ARGS(nid, nr_scanned, nr_freed, nr_unevictable, nr_deactivated, nr_rotated, priority, file), I agree it is helpful. And it was when I investigated aging problem of 32bit when node-lru was introduced. However, the question is we really need all those kinds of information? just enough with nr_taken, nr_deactivated, priority, file? Also, look at minor thing below. Thanks. > + > + TP_STRUCT__entry( > + __field(int, nid) > + __field(unsigned long, nr_scanned) > + __field(unsigned long, nr_freed) > + __field(unsigned long, nr_unevictable) > + __field(unsigned long, nr_deactivated) > + __field(unsigned long, nr_rotated) > + __field(int, priority) > + __field(int, reclaim_flags) > + ), > + > + TP_fast_assign( > + __entry->nid = nid; > + __entry->nr_scanned = nr_scanned; > + __entry->nr_freed = nr_freed; > + __entry->nr_unevictable = nr_unevictable; > + __entry->nr_deactivated = nr_deactivated; > + __entry->nr_rotated = nr_rotated; > + __entry->priority = priority; > + __entry->reclaim_flags = trace_shrink_flags(file); > + ), > + > + TP_printk("nid=%d nr_scanned=%ld nr_freed=%ld nr_unevictable=%ld nr_deactivated=%ld nr_rotated=%ld priority=%d flags=%s", > + __entry->nid, > + __entry->nr_scanned, __entry->nr_freed, __entry->nr_unevictable, > + __entry->nr_deactivated, __entry->nr_rotated, > + __entry->priority, > + show_reclaim_flags(__entry->reclaim_flags)) > +); > + > #endif /* _TRACE_VMSCAN_H */ > > /* This part must be outside protection */ > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 1c24112308d6..77d204660857 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -2487,14 +2487,18 @@ void free_hot_cold_page(struct page *page, bool cold) > /* > * Free a list of 0-order pages > */ > -void free_hot_cold_page_list(struct list_head *list, bool cold) > +int free_hot_cold_page_list(struct list_head *list, bool cold) > { > struct page *page, *next; > + int ret = 0; > > list_for_each_entry_safe(page, next, list, lru) { > trace_mm_page_free_batched(page, cold); > free_hot_cold_page(page, cold); > + ret++; > } > + > + return ret; > } > > /* > diff --git a/mm/vmscan.c b/mm/vmscan.c > index c4abf08861d2..2302a1a58c6e 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -1846,9 +1846,11 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, > * > * The downside is that we have to touch page->_refcount against each page. > * But we had to alter page->flags anyway. > + * > + * Returns the number of pages moved to the given lru. > */ > > -static void move_active_pages_to_lru(struct lruvec *lruvec, > +static int move_active_pages_to_lru(struct lruvec *lruvec, > struct list_head *list, > struct list_head *pages_to_free, > enum lru_list lru) > @@ -1857,6 +1859,7 @@ static void move_active_pages_to_lru(struct lruvec *lruvec, > unsigned long pgmoved = 0; > struct page *page; > int nr_pages; > + int nr_moved = 0; > > while (!list_empty(list)) { > page = lru_to_page(list); > @@ -1882,11 +1885,15 @@ static void move_active_pages_to_lru(struct lruvec *lruvec, > spin_lock_irq(&pgdat->lru_lock); > } else > list_add(&page->lru, pages_to_free); > + } else { > + nr_moved++; > } > } > > if (!is_active_lru(lru)) > __count_vm_events(PGDEACTIVATE, pgmoved); > + > + return nr_moved; > } > > static void shrink_active_list(unsigned long nr_to_scan, > @@ -1902,7 +1909,8 @@ static void shrink_active_list(unsigned long nr_to_scan, > LIST_HEAD(l_inactive); > struct page *page; > struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat; > - unsigned long nr_rotated = 0; > + unsigned long nr_rotated = 0, nr_unevictable = 0; > + unsigned long nr_freed, nr_deactivate, nr_activate; > isolate_mode_t isolate_mode = 0; > int file = is_file_lru(lru); > struct pglist_data *pgdat = lruvec_pgdat(lruvec); > @@ -1935,6 +1943,7 @@ static void shrink_active_list(unsigned long nr_to_scan, > > if (unlikely(!page_evictable(page))) { > putback_lru_page(page); > + nr_unevictable++; > continue; > } > > @@ -1980,13 +1989,16 @@ static void shrink_active_list(unsigned long nr_to_scan, > */ > reclaim_stat->recent_rotated[file] += nr_rotated; > > - move_active_pages_to_lru(lruvec, &l_active, &l_hold, lru); > - move_active_pages_to_lru(lruvec, &l_inactive, &l_hold, lru - LRU_ACTIVE); > + nr_activate = move_active_pages_to_lru(lruvec, &l_active, &l_hold, lru); Who use nr_active in here? > + nr_deactivate = move_active_pages_to_lru(lruvec, &l_inactive, &l_hold, lru - LRU_ACTIVE); > __mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, -nr_taken); > spin_unlock_irq(&pgdat->lru_lock); > > mem_cgroup_uncharge_list(&l_hold); > - free_hot_cold_page_list(&l_hold, true); > + nr_freed = free_hot_cold_page_list(&l_hold, true); > + trace_mm_vmscan_lru_shrink_active(pgdat->node_id, nr_scanned, nr_freed, > + nr_unevictable, nr_deactivate, nr_rotated, > + sc->priority, file); > } > > /* > -- > 2.10.2 > > -- > 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