mm: compaction: cleanup the compaction trace events

As Steven suggested [1], we should access the pointers from the trace
event to avoid dereferencing them to the tracepoint function when the
tracepoint is disabled.

[1] https://lkml.org/lkml/2021/11/3/409

Link: https://lkml.kernel.org/r/4cd393b4d57f8f01ed72c001509b28e3a3b1a8c1.1646985115.git.baolin.wang@linux.alibaba.comSigned-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/trace/events/compaction.h

@@ -67,10 +67,10 @@ DEFINE_EVENT(mm_compaction_isolate_template, mm_compaction_isolate_freepages,
 #ifdef CONFIG_COMPACTION
 TRACE_EVENT(mm_compaction_migratepages,
 
-	TP_PROTO(unsigned long nr_all,
+	TP_PROTO(struct compact_control *cc,
 		unsigned int nr_succeeded),
 
-	TP_ARGS(nr_all, nr_succeeded),
+	TP_ARGS(cc, nr_succeeded),
 
 	TP_STRUCT__entry(
 		__field(unsigned long, nr_migrated)
@@ -79,7 +79,7 @@ TRACE_EVENT(mm_compaction_migratepages,
 
 	TP_fast_assign(
 		__entry->nr_migrated = nr_succeeded;
-		__entry->nr_failed = nr_all - nr_succeeded;
+		__entry->nr_failed = cc->nr_migratepages - nr_succeeded;
 	),
 
 	TP_printk("nr_migrated=%lu nr_failed=%lu",
@@ -88,10 +88,10 @@ TRACE_EVENT(mm_compaction_migratepages,
 );
 
 TRACE_EVENT(mm_compaction_begin,
-	TP_PROTO(unsigned long zone_start, unsigned long migrate_pfn,
-		unsigned long free_pfn, unsigned long zone_end, bool sync),
+	TP_PROTO(struct compact_control *cc, unsigned long zone_start,
+		unsigned long zone_end, bool sync),
 
-	TP_ARGS(zone_start, migrate_pfn, free_pfn, zone_end, sync),
+	TP_ARGS(cc, zone_start, zone_end, sync),
 
 	TP_STRUCT__entry(
 		__field(unsigned long, zone_start)
@@ -103,8 +103,8 @@ TRACE_EVENT(mm_compaction_begin,
 
 	TP_fast_assign(
 		__entry->zone_start = zone_start;
-		__entry->migrate_pfn = migrate_pfn;
-		__entry->free_pfn = free_pfn;
+		__entry->migrate_pfn = cc->migrate_pfn;
+		__entry->free_pfn = cc->free_pfn;
 		__entry->zone_end = zone_end;
 		__entry->sync = sync;
 	),
@@ -118,11 +118,11 @@ TRACE_EVENT(mm_compaction_begin,
 );
 
 TRACE_EVENT(mm_compaction_end,
-	TP_PROTO(unsigned long zone_start, unsigned long migrate_pfn,
-		unsigned long free_pfn, unsigned long zone_end, bool sync,
+	TP_PROTO(struct compact_control *cc, unsigned long zone_start,
+		unsigned long zone_end, bool sync,
 		int status),
 
-	TP_ARGS(zone_start, migrate_pfn, free_pfn, zone_end, sync, status),
+	TP_ARGS(cc, zone_start, zone_end, sync, status),
 
 	TP_STRUCT__entry(
 		__field(unsigned long, zone_start)
@@ -135,8 +135,8 @@ TRACE_EVENT(mm_compaction_end,
 
 	TP_fast_assign(
 		__entry->zone_start = zone_start;
-		__entry->migrate_pfn = migrate_pfn;
-		__entry->free_pfn = free_pfn;
+		__entry->migrate_pfn = cc->migrate_pfn;
+		__entry->free_pfn = cc->free_pfn;
 		__entry->zone_end = zone_end;
 		__entry->sync = sync;
 		__entry->status = status;

mm/compaction.c

@@ -2387,8 +2387,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
 	update_cached = !sync &&
 		cc->zone->compact_cached_migrate_pfn[0] == cc->zone->compact_cached_migrate_pfn[1];
 
-	trace_mm_compaction_begin(start_pfn, cc->migrate_pfn,
-				cc->free_pfn, end_pfn, sync);
+	trace_mm_compaction_begin(cc, start_pfn, end_pfn, sync);
 
 	/* lru_add_drain_all could be expensive with involving other CPUs */
 	lru_add_drain();
@@ -2438,8 +2437,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
 				compaction_free, (unsigned long)cc, cc->mode,
 				MR_COMPACTION, &nr_succeeded);
 
-		trace_mm_compaction_migratepages(cc->nr_migratepages,
-						 nr_succeeded);
+		trace_mm_compaction_migratepages(cc, nr_succeeded);
 
 		/* All pages were either migrated or will be released */
 		cc->nr_migratepages = 0;
@@ -2515,8 +2513,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
 	count_compact_events(COMPACTMIGRATE_SCANNED, cc->total_migrate_scanned);
 	count_compact_events(COMPACTFREE_SCANNED, cc->total_free_scanned);
 
-	trace_mm_compaction_end(start_pfn, cc->migrate_pfn,
-				cc->free_pfn, end_pfn, sync, ret);
+	trace_mm_compaction_end(cc, start_pfn, end_pfn, sync, ret);
 
 	return ret;
 }