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Commit f92310c1 authored by Srivatsa S. Bhat's avatar Srivatsa S. Bhat Committed by Linus Torvalds
Browse files

mm/page_alloc.c: fix the value of fallback_migratetype in alloc_extfrag tracepoint() 



In the current code, the value of fallback_migratetype that is printed
using the mm_page_alloc_extfrag tracepoint, is the value of the
migratetype *after* it has been set to the preferred migratetype (if the
ownership was changed).  Obviously that wouldn't have been the original
intent.  (We already have a separate 'change_ownership' field to tell
whether the ownership of the pageblock was changed from the
fallback_migratetype to the preferred type.)

The intent of the fallback_migratetype field is to show the migratetype
from which we borrowed pages in order to satisfy the allocation request.
So fix the code to print that value correctly.

Signed-off-by: default avatarSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent fef903ef

include/trace/events/kmem.h

+7 −3
Original line number Diff line number Diff line
@@ -268,11 +268,13 @@ TRACE_EVENT(mm_page_alloc_extfrag, 


	TP_PROTO(struct page *page,

			int alloc_order, int fallback_order,

			int alloc_migratetype, int fallback_migratetype),

			int alloc_migratetype, int fallback_migratetype,

			int change_ownership),



	TP_ARGS(page,

		alloc_order, fallback_order,

		alloc_migratetype, fallback_migratetype),

		alloc_migratetype, fallback_migratetype,

		change_ownership),



	TP_STRUCT__entry(

		__field(	struct page *,	page			)
@@ -280,6 +282,7 @@ TRACE_EVENT(mm_page_alloc_extfrag, 
		__field(	int,		fallback_order		)

		__field(	int,		alloc_migratetype	)

		__field(	int,		fallback_migratetype	)

		__field(	int,		change_ownership	)

	),



	TP_fast_assign(
@@ -288,6 +291,7 @@ TRACE_EVENT(mm_page_alloc_extfrag, 
		__entry->fallback_order		= fallback_order;

		__entry->alloc_migratetype	= alloc_migratetype;

		__entry->fallback_migratetype	= fallback_migratetype;

		__entry->change_ownership	= change_ownership;

	),



	TP_printk("page=%p pfn=%lu alloc_order=%d fallback_order=%d pageblock_order=%d alloc_migratetype=%d fallback_migratetype=%d fragmenting=%d change_ownership=%d",
@@ -299,7 +303,7 @@ TRACE_EVENT(mm_page_alloc_extfrag, 
		__entry->alloc_migratetype,

		__entry->fallback_migratetype,

		__entry->fallback_order < pageblock_order,

		__entry->alloc_migratetype == __entry->fallback_migratetype)

		__entry->change_ownership)

);



#endif /* _TRACE_KMEM_H */

mm/page_alloc.c

+3 −2
Original line number Diff line number Diff line
@@ -1101,8 +1101,9 @@ __rmqueue_fallback(struct zone *zone, int order, int start_migratetype) 
			       is_migrate_cma(migratetype)

			     ? migratetype : start_migratetype);



			trace_mm_page_alloc_extfrag(page, order, current_order,

				start_migratetype, new_type);

			trace_mm_page_alloc_extfrag(page, order,

				current_order, start_migratetype, migratetype,

				new_type == start_migratetype);



			return page;

		}