Some compaction tracepoints convert the integer return values to strings using
the compaction_status_string array. This works for in-kernel printing, but not
userspace trace printing of raw captured trace such as via trace-cmd report.
This patch converts the private array to appropriate tracepoint macros that
result in proper userspace support.
trace-cmd output before:
transhuge-stres-4235 [000] 453.149280: mm_compaction_finished: node=0
zone=ffffffff81815d7a order=9 ret=
after:
transhuge-stres-4235 [000] 453.149280: mm_compaction_finished: node=0
zone=ffffffff81815d7a order=9 ret=partial
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Reviewed-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
---
v2: adjust comment for adding new states, add Reviewed-by.
include/linux/compaction.h | 2 +-
include/trace/events/compaction.h | 33 +++++++++++++++++++++++++++++++--
mm/compaction.c | 11 -----------
3 files changed, 32 insertions(+), 14 deletions(-)
diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index aa8f61c..f14ba98 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -15,7 +15,7 @@
/* 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 */
+/* When adding new states, please adjust include/trace/events/compaction.h */
/* Used to signal whether compaction detected need_sched() or lock contention */
/* No contention detected */
diff --git a/include/trace/events/compaction.h b/include/trace/events/compaction.h
index 9a6a3fe..1275a55 100644
--- a/include/trace/events/compaction.h
+++ b/include/trace/events/compaction.h
@@ -9,6 +9,35 @@
#include <linux/tracepoint.h>
#include <trace/events/gfpflags.h>
+#define COMPACTION_STATUS \
+ EM( COMPACT_DEFERRED, "deferred") \
+ EM( COMPACT_SKIPPED, "skipped") \
+ EM( COMPACT_CONTINUE, "continue") \
+ EM( COMPACT_PARTIAL, "partial") \
+ EM( COMPACT_COMPLETE, "complete") \
+ EM( COMPACT_NO_SUITABLE_PAGE, "no_suitable_page") \
+ EMe(COMPACT_NOT_SUITABLE_ZONE, "not_suitable_zone")
+
+/*
+ * First define the enums in the above macros to be exported to userspace
+ * via TRACE_DEFINE_ENUM().
+ */
+#undef EM
+#undef EMe
+#define EM(a, b) TRACE_DEFINE_ENUM(a);
+#define EMe(a, b) TRACE_DEFINE_ENUM(a);
+
+COMPACTION_STATUS
+
+/*
+ * Now redefine the EM() and EMe() macros to map the enums to the strings
+ * that will be printed in the output.
+ */
+#undef EM
+#undef EMe
+#define EM(a, b) {a, b},
+#define EMe(a, b) {a, b}
+
DECLARE_EVENT_CLASS(mm_compaction_isolate_template,
TP_PROTO(
@@ -161,7 +190,7 @@ TRACE_EVENT(mm_compaction_end,
__entry->free_pfn,
__entry->zone_end,
__entry->sync ? "sync" : "async",
- compaction_status_string[__entry->status])
+ __print_symbolic(__entry->status, COMPACTION_STATUS))
);
TRACE_EVENT(mm_compaction_try_to_compact_pages,
@@ -217,7 +246,7 @@ DECLARE_EVENT_CLASS(mm_compaction_suitable_template,
__entry->nid,
__entry->name,
__entry->order,
- compaction_status_string[__entry->ret])
+ __print_symbolic(__entry->ret, COMPACTION_STATUS))
);
DEFINE_EVENT(mm_compaction_suitable_template, mm_compaction_finished,
diff --git a/mm/compaction.c b/mm/compaction.c
index a8e6593..a5849c4 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -35,17 +35,6 @@ static inline void count_compact_events(enum vm_event_item item, long delta)
#endif
#if defined CONFIG_COMPACTION || defined CONFIG_CMA
-#ifdef CONFIG_TRACEPOINTS
-static const char *const compaction_status_string[] = {
- "deferred",
- "skipped",
- "continue",
- "partial",
- "complete",
- "no_suitable_page",
- "not_suitable_zone",
-};
-#endif
#define CREATE_TRACE_POINTS
#include <trace/events/compaction.h>
--
2.5.1
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