Commit 837d026d authored by Joonsoo Kim's avatar Joonsoo Kim Committed by Linus Torvalds
Browse files

mm/compaction: more trace to understand when/why compaction start/finish 

It is not well analyzed that when/why compaction start/finish or not.
With these new tracepoints, we can know much more about start/finish
reason of compaction.  I can find following bug with these tracepoint.

http://www.spinics.net/lists/linux-mm/msg81582.html



Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e34d85f0

include/linux/compaction.h

+3 −0
Original line number Diff line number Diff line
@@ -12,6 +12,9 @@ 
#define COMPACT_PARTIAL		3

/* The full zone was compacted */

#define COMPACT_COMPLETE	4

/* For more detailed tracepoint output */

#define COMPACT_NO_SUITABLE_PAGE	5

#define COMPACT_NOT_SUITABLE_ZONE	6

/* When adding new state, please change compaction_status_string, too */



/* Used to signal whether compaction detected need_sched() or lock contention */

include/trace/events/compaction.h

+74 −0
Original line number Diff line number Diff line
@@ -164,6 +164,80 @@ TRACE_EVENT(mm_compaction_end, 
		compaction_status_string[__entry->status])

);



TRACE_EVENT(mm_compaction_try_to_compact_pages,



	TP_PROTO(

		int order,

		gfp_t gfp_mask,

		enum migrate_mode mode),



	TP_ARGS(order, gfp_mask, mode),



	TP_STRUCT__entry(

		__field(int, order)

		__field(gfp_t, gfp_mask)

		__field(enum migrate_mode, mode)

	),



	TP_fast_assign(

		__entry->order = order;

		__entry->gfp_mask = gfp_mask;

		__entry->mode = mode;

	),



	TP_printk("order=%d gfp_mask=0x%x mode=%d",

		__entry->order,

		__entry->gfp_mask,

		(int)__entry->mode)

);



DECLARE_EVENT_CLASS(mm_compaction_suitable_template,



	TP_PROTO(struct zone *zone,

		int order,

		int ret),



	TP_ARGS(zone, order, ret),



	TP_STRUCT__entry(

		__field(int, nid)

		__field(char *, name)

		__field(int, order)

		__field(int, ret)

	),



	TP_fast_assign(

		__entry->nid = zone_to_nid(zone);

		__entry->name = (char *)zone->name;

		__entry->order = order;

		__entry->ret = ret;

	),



	TP_printk("node=%d zone=%-8s order=%d ret=%s",

		__entry->nid,

		__entry->name,

		__entry->order,

		compaction_status_string[__entry->ret])

);



DEFINE_EVENT(mm_compaction_suitable_template, mm_compaction_finished,



	TP_PROTO(struct zone *zone,

		int order,

		int ret),



	TP_ARGS(zone, order, ret)

);



DEFINE_EVENT(mm_compaction_suitable_template, mm_compaction_suitable,



	TP_PROTO(struct zone *zone,

		int order,

		int ret),



	TP_ARGS(zone, order, ret)

);



#endif /* _TRACE_COMPACTION_H */



/* This part must be outside protection */

mm/compaction.c

+34 −4
Original line number Diff line number Diff line
@@ -41,6 +41,8 @@ static const char *const compaction_status_string[] = { 
	"continue",

	"partial",

	"complete",

	"no_suitable_page",

	"not_suitable_zone",

};

#endif
@@ -1049,7 +1051,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone, 
	return cc->nr_migratepages ? ISOLATE_SUCCESS : ISOLATE_NONE;

}



static int compact_finished(struct zone *zone, struct compact_control *cc,

static int __compact_finished(struct zone *zone, struct compact_control *cc,

			    const int migratetype)

{

	unsigned int order;
@@ -1104,7 +1106,20 @@ static int compact_finished(struct zone *zone, struct compact_control *cc, 
			return COMPACT_PARTIAL;

	}



	return COMPACT_CONTINUE;

	return COMPACT_NO_SUITABLE_PAGE;

}



static int compact_finished(struct zone *zone, struct compact_control *cc,

			    const int migratetype)

{

	int ret;



	ret = __compact_finished(zone, cc, migratetype);

	trace_mm_compaction_finished(zone, cc->order, ret);

	if (ret == COMPACT_NO_SUITABLE_PAGE)

		ret = COMPACT_CONTINUE;



	return ret;

}



/*
@@ -1114,7 +1129,7 @@ static int compact_finished(struct zone *zone, struct compact_control *cc, 
 *   COMPACT_PARTIAL  - If the allocation would succeed without compaction

 *   COMPACT_CONTINUE - If compaction should run now

 */

unsigned long compaction_suitable(struct zone *zone, int order,

static unsigned long __compaction_suitable(struct zone *zone, int order,

					int alloc_flags, int classzone_idx)

{

	int fragindex;
@@ -1158,11 +1173,24 @@ unsigned long compaction_suitable(struct zone *zone, int order, 
	 */

	fragindex = fragmentation_index(zone, order);

	if (fragindex >= 0 && fragindex <= sysctl_extfrag_threshold)

		return COMPACT_SKIPPED;

		return COMPACT_NOT_SUITABLE_ZONE;



	return COMPACT_CONTINUE;

}



unsigned long compaction_suitable(struct zone *zone, int order,

					int alloc_flags, int classzone_idx)

{

	unsigned long ret;



	ret = __compaction_suitable(zone, order, alloc_flags, classzone_idx);

	trace_mm_compaction_suitable(zone, order, ret);

	if (ret == COMPACT_NOT_SUITABLE_ZONE)

		ret = COMPACT_SKIPPED;



	return ret;

}



static int compact_zone(struct zone *zone, struct compact_control *cc)

{

	int ret;
@@ -1376,6 +1404,8 @@ unsigned long try_to_compact_pages(gfp_t gfp_mask, unsigned int order, 
	if (!order || !may_enter_fs || !may_perform_io)

		return COMPACT_SKIPPED;



	trace_mm_compaction_try_to_compact_pages(order, gfp_mask, mode);



	/* Compact each zone in the list */

	for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,

								ac->nodemask) {

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