Messages in this thread Patch in this message | | | From | Mel Gorman <> | Subject | [PATCH 3/3] tracing, page-allocator: Add trace event for page traffic related to the buddy lists | Date | Tue, 28 Jul 2009 23:23:39 +0100 |
| |
The page allocation trace event reports that a page was successfully allocated but it does not specify where it came from. When analysing performance, it can be important to distinguish between pages coming from the per-cpu allocator and pages coming from the buddy lists as the latter requires the zone lock to the taken and more data structures to be examined.
This patch adds a trace event for __rmqueue reporting when a page is being allocated from the buddy lists. It distinguishes between being called to refill the per-cpu lists or whether it is a high-order allocation. Similarly, this patch adds an event to catch when the PCP lists are being drained a little and pages are going back to the buddy lists. These two events can be used as an indicator of how often the zone lock is being taken.
Signed-off-by: Mel Gorman <mel@csn.ul.ie> --- include/trace/events/kmem.h | 54 +++++++++++++++++++++++++++++++++++++++++++ mm/page_alloc.c | 2 + 2 files changed, 56 insertions(+), 0 deletions(-)
diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h index 91a057c..fbc3779 100644 --- a/include/trace/events/kmem.h +++ b/include/trace/events/kmem.h @@ -283,6 +283,60 @@ TRACE_EVENT(__alloc_pages_nodemask, show_gfp_flags(__entry->gfp_flags)) ); +TRACE_EVENT(__rmqueue, + + TP_PROTO(const void *page, unsigned int order, + int migratetype, int percpu_refill), + + TP_ARGS(page, order, migratetype, percpu_refill), + + TP_STRUCT__entry( + __field( const void *, page ) + __field( unsigned int, order ) + __field( int, migratetype ) + __field( int, percpu_refill ) + ), + + TP_fast_assign( + __entry->page = page; + __entry->order = order; + __entry->migratetype = migratetype; + __entry->percpu_refill = percpu_refill; + ), + + TP_printk("page = %p pfn=%lu order=%u migratetype=%d percpu_refill=%d", + __entry->page, + page_to_pfn((struct page *)__entry->page), + __entry->order, + __entry->migratetype, + __entry->percpu_refill) +); + +TRACE_EVENT(free_pages_bulk, + + TP_PROTO(const void *page, int order, int migratetype), + + TP_ARGS(page, order, migratetype), + + TP_STRUCT__entry( + __field( const void *, page ) + __field( int, order ) + __field( int, migratetype ) + ), + + TP_fast_assign( + __entry->page = page; + __entry->order = order; + __entry->migratetype = migratetype; + ), + + TP_printk("page=%p pfn=%lu order=%d migratetype=%d", + __entry->page, + page_to_pfn((struct page *)__entry->page), + __entry->order, + __entry->migratetype) +); + TRACE_EVENT(__rmqueue_fallback, TP_PROTO(const void *page, diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3fc9f09..f96bf2c 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -535,6 +535,7 @@ static void free_pages_bulk(struct zone *zone, int count, page = list_entry(list->prev, struct page, lru); /* have to delete it as __free_one_page list manipulates */ list_del(&page->lru); + trace_free_pages_bulk(page, order, page_private(page)); __free_one_page(page, zone, order, page_private(page)); } spin_unlock(&zone->lock); @@ -878,6 +879,7 @@ retry_reserve: } } + trace___rmqueue(page, order, migratetype, order == 0); return page; } -- 1.6.3.3
| |