From b7aba6984dc048503b69c2a885098cdd430832bf Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 13 Jan 2011 15:45:54 -0800 Subject: mm: compaction: add trace events for memory compaction activity In preparation for a patches promoting the use of memory compaction over lumpy reclaim, this patch adds trace points for memory compaction activity. Using them, we can monitor the scanning activity of the migration and free page scanners as well as the number and success rates of pages passed to page migration. Signed-off-by: Mel Gorman Cc: Andrea Arcangeli Cc: KOSAKI Motohiro Cc: Rik van Riel Cc: Johannes Weiner Cc: Andy Whitcroft Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/compaction.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'mm') diff --git a/mm/compaction.c b/mm/compaction.c index 1a8894e..20011a8 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -16,6 +16,9 @@ #include #include "internal.h" +#define CREATE_TRACE_POINTS +#include + /* * compact_control is used to track pages being migrated and the free pages * they are being migrated to during memory compaction. The free_pfn starts @@ -60,7 +63,7 @@ static unsigned long isolate_freepages_block(struct zone *zone, struct list_head *freelist) { unsigned long zone_end_pfn, end_pfn; - int total_isolated = 0; + int nr_scanned = 0, total_isolated = 0; struct page *cursor; /* Get the last PFN we should scan for free pages at */ @@ -81,6 +84,7 @@ static unsigned long isolate_freepages_block(struct zone *zone, if (!pfn_valid_within(blockpfn)) continue; + nr_scanned++; if (!PageBuddy(page)) continue; @@ -100,6 +104,7 @@ static unsigned long isolate_freepages_block(struct zone *zone, } } + trace_mm_compaction_isolate_freepages(nr_scanned, total_isolated); return total_isolated; } @@ -234,6 +239,7 @@ static unsigned long isolate_migratepages(struct zone *zone, struct compact_control *cc) { unsigned long low_pfn, end_pfn; + unsigned long nr_scanned = 0, nr_isolated = 0; struct list_head *migratelist = &cc->migratepages; /* Do not scan outside zone boundaries */ @@ -266,6 +272,7 @@ static unsigned long isolate_migratepages(struct zone *zone, struct page *page; if (!pfn_valid_within(low_pfn)) continue; + nr_scanned++; /* Get the page and skip if free */ page = pfn_to_page(low_pfn); @@ -280,6 +287,7 @@ static unsigned long isolate_migratepages(struct zone *zone, del_page_from_lru_list(zone, page, page_lru(page)); list_add(&page->lru, migratelist); cc->nr_migratepages++; + nr_isolated++; /* Avoid isolating too much */ if (cc->nr_migratepages == COMPACT_CLUSTER_MAX) @@ -291,6 +299,8 @@ static unsigned long isolate_migratepages(struct zone *zone, spin_unlock_irq(&zone->lru_lock); cc->migrate_pfn = low_pfn; + trace_mm_compaction_isolate_migratepages(nr_scanned, nr_isolated); + return cc->nr_migratepages; } @@ -401,6 +411,8 @@ static int compact_zone(struct zone *zone, struct compact_control *cc) count_vm_events(COMPACTPAGES, nr_migrate - nr_remaining); if (nr_remaining) count_vm_events(COMPACTPAGEFAILED, nr_remaining); + trace_mm_compaction_migratepages(nr_migrate - nr_remaining, + nr_remaining); /* Release LRU pages not migrated */ if (!list_empty(&cc->migratepages)) { -- cgit v1.1