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From: Mel Gorman <mgorman@suse.de>
To: Stable <stable@vger.kernel.org>
Cc: Linux-MM <linux-mm@kvack.org>,
	LKML <linux-kernel@vger.kernel.org>, Mel Gorman <mgorman@suse.de>
Subject: [PATCH 06/34] vmscan: add shrink_slab tracepoints
Date: Mon, 23 Jul 2012 14:38:19 +0100	[thread overview]
Message-ID: <1343050727-3045-7-git-send-email-mgorman@suse.de> (raw)
In-Reply-To: <1343050727-3045-1-git-send-email-mgorman@suse.de>

From: Dave Chinner <dchinner@redhat.com>

commit 095760730c1047c69159ce88021a7fa3833502c8 upstream.

Stable note: This patch makes later patches easier to apply but otherwise
	has little to justify it. It is a diagnostic patch that was part
	of a series addressing excessive slab shrinking after GFP_NOFS
	failures. There is detailed information on the series' motivation
	at https://lkml.org/lkml/2011/6/2/42 .

It is impossible to understand what the shrinkers are actually doing
without instrumenting the code, so add a some tracepoints to allow
insight to be gained.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
 include/trace/events/vmscan.h |   77 +++++++++++++++++++++++++++++++++++++++++
 mm/vmscan.c                   |    8 ++++-
 2 files changed, 84 insertions(+), 1 deletion(-)

diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index b2c33bd..36851f7 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -179,6 +179,83 @@ DEFINE_EVENT(mm_vmscan_direct_reclaim_end_template, mm_vmscan_memcg_softlimit_re
 	TP_ARGS(nr_reclaimed)
 );
 
+TRACE_EVENT(mm_shrink_slab_start,
+	TP_PROTO(struct shrinker *shr, struct shrink_control *sc,
+		long nr_objects_to_shrink, unsigned long pgs_scanned,
+		unsigned long lru_pgs, unsigned long cache_items,
+		unsigned long long delta, unsigned long total_scan),
+
+	TP_ARGS(shr, sc, nr_objects_to_shrink, pgs_scanned, lru_pgs,
+		cache_items, delta, total_scan),
+
+	TP_STRUCT__entry(
+		__field(struct shrinker *, shr)
+		__field(void *, shrink)
+		__field(long, nr_objects_to_shrink)
+		__field(gfp_t, gfp_flags)
+		__field(unsigned long, pgs_scanned)
+		__field(unsigned long, lru_pgs)
+		__field(unsigned long, cache_items)
+		__field(unsigned long long, delta)
+		__field(unsigned long, total_scan)
+	),
+
+	TP_fast_assign(
+		__entry->shr = shr;
+		__entry->shrink = shr->shrink;
+		__entry->nr_objects_to_shrink = nr_objects_to_shrink;
+		__entry->gfp_flags = sc->gfp_mask;
+		__entry->pgs_scanned = pgs_scanned;
+		__entry->lru_pgs = lru_pgs;
+		__entry->cache_items = cache_items;
+		__entry->delta = delta;
+		__entry->total_scan = total_scan;
+	),
+
+	TP_printk("%pF %p: objects to shrink %ld gfp_flags %s pgs_scanned %ld lru_pgs %ld cache items %ld delta %lld total_scan %ld",
+		__entry->shrink,
+		__entry->shr,
+		__entry->nr_objects_to_shrink,
+		show_gfp_flags(__entry->gfp_flags),
+		__entry->pgs_scanned,
+		__entry->lru_pgs,
+		__entry->cache_items,
+		__entry->delta,
+		__entry->total_scan)
+);
+
+TRACE_EVENT(mm_shrink_slab_end,
+	TP_PROTO(struct shrinker *shr, int shrinker_retval,
+		long unused_scan_cnt, long new_scan_cnt),
+
+	TP_ARGS(shr, shrinker_retval, unused_scan_cnt, new_scan_cnt),
+
+	TP_STRUCT__entry(
+		__field(struct shrinker *, shr)
+		__field(void *, shrink)
+		__field(long, unused_scan)
+		__field(long, new_scan)
+		__field(int, retval)
+		__field(long, total_scan)
+	),
+
+	TP_fast_assign(
+		__entry->shr = shr;
+		__entry->shrink = shr->shrink;
+		__entry->unused_scan = unused_scan_cnt;
+		__entry->new_scan = new_scan_cnt;
+		__entry->retval = shrinker_retval;
+		__entry->total_scan = new_scan_cnt - unused_scan_cnt;
+	),
+
+	TP_printk("%pF %p: unused scan count %ld new scan count %ld total_scan %ld last shrinker return val %d",
+		__entry->shrink,
+		__entry->shr,
+		__entry->unused_scan,
+		__entry->new_scan,
+		__entry->total_scan,
+		__entry->retval)
+);
 
 DECLARE_EVENT_CLASS(mm_vmscan_lru_isolate_template,
 
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 72340b84..d875058 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -250,6 +250,7 @@ unsigned long shrink_slab(struct shrink_control *shrink,
 		unsigned long long delta;
 		unsigned long total_scan;
 		unsigned long max_pass;
+		int shrink_ret = 0;
 
 		max_pass = do_shrinker_shrink(shrinker, shrink, 0);
 		delta = (4 * nr_pages_scanned) / shrinker->seeks;
@@ -274,9 +275,12 @@ unsigned long shrink_slab(struct shrink_control *shrink,
 		total_scan = shrinker->nr;
 		shrinker->nr = 0;
 
+		trace_mm_shrink_slab_start(shrinker, shrink, total_scan,
+					nr_pages_scanned, lru_pages,
+					max_pass, delta, total_scan);
+
 		while (total_scan >= SHRINK_BATCH) {
 			long this_scan = SHRINK_BATCH;
-			int shrink_ret;
 			int nr_before;
 
 			nr_before = do_shrinker_shrink(shrinker, shrink, 0);
@@ -293,6 +297,8 @@ unsigned long shrink_slab(struct shrink_control *shrink,
 		}
 
 		shrinker->nr += total_scan;
+		trace_mm_shrink_slab_end(shrinker, shrink_ret, total_scan,
+					 shrinker->nr);
 	}
 	up_read(&shrinker_rwsem);
 out:
-- 
1.7.9.2

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  parent reply	other threads:[~2012-07-23 13:38 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-23 13:38 [PATCH 00/34] Memory management performance backports for -stable V2 Mel Gorman
2012-07-23 13:38 ` [PATCH 01/34] mm: vmstat: cache align vm_stat Mel Gorman
2012-07-23 13:38 ` [PATCH 02/34] mm: memory hotplug: Check if pages are correctly reserved on a per-section basis Mel Gorman
2012-07-23 13:38 ` [PATCH 03/34] mm: Reduce the amount of work done when updating min_free_kbytes Mel Gorman
2012-07-24 22:47   ` Greg KH
2012-07-25  7:57     ` Mel Gorman
2012-07-23 13:38 ` [PATCH 04/34] mm: vmscan: fix force-scanning small targets without swap Mel Gorman
2012-07-23 13:38 ` [PATCH 05/34] vmscan: clear ZONE_CONGESTED for zone with good watermark Mel Gorman
2012-07-23 13:38 ` Mel Gorman [this message]
2012-07-23 13:38 ` [PATCH 07/34] vmscan: shrinker->nr updates race and go wrong Mel Gorman
2012-07-23 13:38 ` [PATCH 08/34] vmscan: reduce wind up shrinker->nr when shrinker can't do work Mel Gorman
2012-07-23 13:38 ` [PATCH 09/34] mm: limit direct reclaim for higher order allocations Mel Gorman
2012-07-23 13:38 ` [PATCH 10/34] mm: Abort reclaim/compaction if compaction can proceed Mel Gorman
2012-07-23 13:38 ` [PATCH 11/34] mm: compaction: trivial clean up in acct_isolated() Mel Gorman
2012-07-23 13:38 ` [PATCH 12/34] mm: change isolate mode from #define to bitwise type Mel Gorman
2012-07-23 13:38 ` [PATCH 13/34] mm: compaction: make isolate_lru_page() filter-aware Mel Gorman
2012-07-23 13:38 ` [PATCH 14/34] mm: zone_reclaim: " Mel Gorman
2012-07-23 13:38 ` [PATCH 15/34] mm: migration: clean up unmap_and_move() Mel Gorman
2012-07-25 15:45   ` Greg KH
2012-07-25 16:04     ` Mel Gorman
2012-07-25 18:03       ` Greg KH
2012-07-23 13:38 ` [PATCH 16/34] mm: compaction: Allow compaction to isolate dirty pages Mel Gorman
2012-07-25 15:47   ` Greg KH
2012-07-25 16:07     ` Mel Gorman
2012-07-23 13:38 ` [PATCH 17/34] mm: compaction: Determine if dirty pages can be migrated without blocking within ->migratepage Mel Gorman
2012-07-23 13:38 ` [PATCH 18/34] mm: page allocator: Do not call direct reclaim for THP allocations while compaction is deferred Mel Gorman
2012-07-23 13:38 ` [PATCH 19/34] mm: compaction: make isolate_lru_page() filter-aware again Mel Gorman
2012-07-23 13:38 ` [PATCH 20/34] kswapd: avoid unnecessary rebalance after an unsuccessful balancing Mel Gorman
2012-07-23 13:38 ` [PATCH 21/34] kswapd: assign new_order and new_classzone_idx after wakeup in sleeping Mel Gorman
2012-07-23 13:38 ` [PATCH 22/34] mm: compaction: Introduce sync-light migration for use by compaction Mel Gorman
2012-07-23 13:38 ` [PATCH 23/34] mm: vmscan: When reclaiming for compaction, ensure there are sufficient free pages available Mel Gorman
2012-07-23 13:38 ` [PATCH 24/34] mm: vmscan: Do not OOM if aborting reclaim to start compaction Mel Gorman
2012-07-23 13:38 ` [PATCH 25/34] mm: vmscan: Check if reclaim should really abort even if compaction_ready() is true for one zone Mel Gorman
2012-07-25 19:51   ` Greg KH
2012-07-23 13:38 ` [PATCH 26/34] vmscan: promote shared file mapped pages Mel Gorman
2012-07-23 13:38 ` [PATCH 27/34] vmscan: activate executable pages after first usage Mel Gorman
2012-07-23 13:38 ` [PATCH 28/34] mm/vmscan.c: consider swap space when deciding whether to continue reclaim Mel Gorman
2012-07-23 13:38 ` [PATCH 29/34] mm: test PageSwapBacked in lumpy reclaim Mel Gorman
2012-07-23 13:38 ` [PATCH 30/34] mm: vmscan: Do not force kswapd to scan small targets Mel Gorman
2012-07-25 19:59   ` Greg KH
2012-07-25 21:35     ` Mel Gorman
2012-07-25 21:44       ` Greg KH
2012-07-23 13:38 ` [PATCH 31/34] cpusets: avoid looping when storing to mems_allowed if one node remains set Mel Gorman
2012-07-23 13:38 ` [PATCH 32/34] cpusets: stall when updating mems_allowed for mempolicy or disjoint nodemask Mel Gorman
2012-07-23 13:38 ` [PATCH 33/34] cpuset: mm: Reduce large amounts of memory barrier related damage v3 Mel Gorman
2012-07-23 13:38 ` [PATCH 34/34] mm/hugetlb: fix warning in alloc_huge_page/dequeue_huge_page_vma Mel Gorman
2012-07-24  5:58 ` [PATCH 00/34] Memory management performance backports for -stable V2 Mike Galbraith
2012-07-24  8:10   ` Mel Gorman
2012-07-24 13:18   ` Hillf Danton
2012-07-24 13:27     ` Mel Gorman
2012-07-24 13:34       ` Hillf Danton
2012-07-24 13:53         ` Mel Gorman
2012-07-24 14:11           ` Hillf Danton
2012-07-24 13:52     ` Mike Galbraith
2012-07-24 14:18       ` Hillf Danton
2012-07-24 14:41         ` Mike Galbraith
2012-07-25 22:30 ` Greg KH
2012-07-25 22:48   ` Mel Gorman
2012-07-30  1:13 ` Ben Hutchings
  -- strict thread matches above, loose matches on Subject: below --
2012-07-19 14:36 [PATCH 00/34] Memory management performance backports for -stable Mel Gorman
2012-07-19 14:36 ` [PATCH 06/34] vmscan: add shrink_slab tracepoints Mel Gorman

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