mm/compaction: enhance tracepoint output for compaction begin/end

We now have tracepoint for begin event of compaction and it prints start
position of both scanners, but, tracepoint for end event of compaction
doesn't print finish position of both scanners.  It'd be also useful to
know finish position of both scanners so this patch add it.  It will help
to find odd behavior or problem on compaction internal logic.

And mode is added to both begin/end tracepoint output, since according to
mode, compaction behavior is quite different.

And lastly, status format is changed to string rather than status number
for readability.

[akpm@linux-foundation.org: fix sparse warning]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/compaction.c b/mm/compaction.c
index 9c7e690..66f7c36 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -34,6 +34,15 @@
 #endif
 
 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
+#ifdef CONFIG_TRACEPOINTS
+static const char *const compaction_status_string[] = {
+	"deferred",
+	"skipped",
+	"continue",
+	"partial",
+	"complete",
+};
+#endif
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/compaction.h>
@@ -1197,7 +1206,8 @@
 		zone->compact_cached_migrate_pfn[1] = cc->migrate_pfn;
 	}
 
-	trace_mm_compaction_begin(start_pfn, cc->migrate_pfn, cc->free_pfn, end_pfn);
+	trace_mm_compaction_begin(start_pfn, cc->migrate_pfn,
+				cc->free_pfn, end_pfn, sync);
 
 	migrate_prep_local();
 
@@ -1299,7 +1309,8 @@
 			zone->compact_cached_free_pfn = free_pfn;
 	}
 
-	trace_mm_compaction_end(ret);
+	trace_mm_compaction_end(start_pfn, cc->migrate_pfn,
+				cc->free_pfn, end_pfn, sync, ret);
 
 	return ret;
 }