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authorMel Gorman <mel@csn.ul.ie>2009-09-21 17:02:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-22 07:17:34 -0700
commit4b4f278c030aa4b6ee0915f396e9a9478d92d610 (patch)
tree10825c2d197977bc9080093a6ecbd3ce80723876 /mm/page_alloc.c
parent38a398572fa2d8124f7479e40db581b5b72719c9 (diff)
downloadconfigs-4b4f278c030aa4b6ee0915f396e9a9478d92d610.tar.gz
tracing, page-allocator: add trace events for page allocation and page freeing
This patch adds trace events for the allocation and freeing of pages, including the freeing of pagevecs. Using the events, it will be known what struct page and pfns are being allocated and freed and what the call site was in many cases. The page alloc tracepoints be used as an indicator as to whether the workload was heavily dependant on the page allocator or not. You can make a guess based on vmstat but you can't get a per-process breakdown. Depending on the call path, the call_site for page allocation may be __get_free_pages() instead of a useful callsite. Instead of passing down a return address similar to slab debugging, the user should enable the stacktrace and seg-addr options to get a proper stack trace. The pagevec free tracepoint has a different usecase. It can be used to get a idea of how many pages are being dumped off the LRU and whether it is kswapd doing the work or a process doing direct reclaim. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Ingo Molnar <mingo@elte.hu> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Li Ming Chun <macli@brc.ubc.ca> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
-rw-r--r--mm/page_alloc.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 913a8ebd3a8..80f954d82d7 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1076,6 +1076,7 @@ static void free_hot_cold_page(struct page *page, int cold)
void free_hot_page(struct page *page)
{
+ trace_mm_page_free_direct(page, 0);
free_hot_cold_page(page, 0);
}
@@ -1920,6 +1921,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
zonelist, high_zoneidx, nodemask,
preferred_zone, migratetype);
+ trace_mm_page_alloc(page, order, gfp_mask, migratetype);
return page;
}
EXPORT_SYMBOL(__alloc_pages_nodemask);
@@ -1954,13 +1956,16 @@ void __pagevec_free(struct pagevec *pvec)
{
int i = pagevec_count(pvec);
- while (--i >= 0)
+ while (--i >= 0) {
+ trace_mm_pagevec_free(pvec->pages[i], pvec->cold);
free_hot_cold_page(pvec->pages[i], pvec->cold);
+ }
}
void __free_pages(struct page *page, unsigned int order)
{
if (put_page_testzero(page)) {
+ trace_mm_page_free_direct(page, order);
if (order == 0)
free_hot_page(page);
else