mm/compaction: print current range where compaction work

It'd be useful to know current range where compaction work for detailed
analysis.  With it, we can know pageblock where we actually scan and
isolate, and, how much pages we try in that pageblock and can guess why it
doesn't become freepage with pageblock order roughly.

Signed-off-by: Joonsoo Kim <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: David Rientjes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: JoonsooKim

include/trace/events/compaction.h

@@ -11,39 +11,55 @@
 
 DECLARE_EVENT_CLASS(mm_compaction_isolate_template,
 
-	TP_PROTO(unsigned long nr_scanned,
+	TP_PROTO(
+		unsigned long start_pfn,
+		unsigned long end_pfn,
+		unsigned long nr_scanned,
 		unsigned long nr_taken),
 
-	TP_ARGS(nr_scanned, nr_taken),
+	TP_ARGS(start_pfn, end_pfn, nr_scanned, nr_taken),
 
 	TP_STRUCT__entry(
+		__field(unsigned long, start_pfn)
+		__field(unsigned long, end_pfn)
 		__field(unsigned long, nr_scanned)
 		__field(unsigned long, nr_taken)
 	),
 
 	TP_fast_assign(
+		__entry->start_pfn = start_pfn;
+		__entry->end_pfn = end_pfn;
 		__entry->nr_scanned = nr_scanned;
 		__entry->nr_taken = nr_taken;
 	),
 
-	TP_printk("nr_scanned=%lu nr_taken=%lu",
+	TP_printk("range=(0x%lx ~ 0x%lx) nr_scanned=%lu nr_taken=%lu",
+		__entry->start_pfn,
+		__entry->end_pfn,
 		__entry->nr_scanned,
 		__entry->nr_taken)
 );
 
 DEFINE_EVENT(mm_compaction_isolate_template, mm_compaction_isolate_migratepages,
 
-	TP_PROTO(unsigned long nr_scanned,
+	TP_PROTO(
+		unsigned long start_pfn,
+		unsigned long end_pfn,
+		unsigned long nr_scanned,
 		unsigned long nr_taken),
 
-	TP_ARGS(nr_scanned, nr_taken)
+	TP_ARGS(start_pfn, end_pfn, nr_scanned, nr_taken)
 );
 
 DEFINE_EVENT(mm_compaction_isolate_template, mm_compaction_isolate_freepages,
-	TP_PROTO(unsigned long nr_scanned,
+
+	TP_PROTO(
+		unsigned long start_pfn,
+		unsigned long end_pfn,
+		unsigned long nr_scanned,
 		unsigned long nr_taken),
 
-	TP_ARGS(nr_scanned, nr_taken)
+	TP_ARGS(start_pfn, end_pfn, nr_scanned, nr_taken)
 );
 
 TRACE_EVENT(mm_compaction_migratepages,

mm/compaction.c

@@ -430,11 +430,12 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
 
 	}
 
+	trace_mm_compaction_isolate_freepages(*start_pfn, blockpfn,
+					nr_scanned, total_isolated);
+
 	/* Record how far we have got within the block */
 	*start_pfn = blockpfn;
 
-	trace_mm_compaction_isolate_freepages(nr_scanned, total_isolated);
-
 	/*
 	 * If strict isolation is requested by CMA then check that all the
 	 * pages requested were isolated. If there were any failures, 0 is
@@ -590,6 +591,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
 	unsigned long flags = 0;
 	bool locked = false;
 	struct page *page = NULL, *valid_page = NULL;
+	unsigned long start_pfn = low_pfn;
 
 	/*
 	 * Ensure that there are not too many pages isolated from the LRU
@@ -750,7 +752,8 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
 	if (low_pfn == end_pfn)
 		update_pageblock_skip(cc, valid_page, nr_isolated, true);
 
-	trace_mm_compaction_isolate_migratepages(nr_scanned, nr_isolated);
+	trace_mm_compaction_isolate_migratepages(start_pfn, low_pfn,
+						nr_scanned, nr_isolated);
 
 	count_compact_events(COMPACTMIGRATE_SCANNED, nr_scanned);
 	if (nr_isolated)