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perf tools: Allow out of order messages in forced flush

tip:perf/core tip-bot for Jiri Olsa 1 participant 1 message Aug 13, 2014 perf events

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Commit-ID:  b0a45203a75a800015828ac89f2945981019b65b
Gitweb:     http://git.kernel.org/tip/b0a45203a75a800015828ac89f2945981019b65b
Author:     Jiri Olsa <[email protected]>
AuthorDate: Thu, 12 Jun 2014 09:50:11 +0200
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Tue, 12 Aug 2014 12:03:02 -0300

perf tools: Allow out of order messages in forced flush

In forced flush (OE_FLUSH__HALF) we break the rules of the flush timestamp via PERF_RECORD_FINISHED_ROUND event, so we could get out of order event.

Do not force error in this case plus changing the output warning to use WARN_ONCE.

Signed-off-by Jiri Olsa <[email protected]>
Acked-by David Ahern <[email protected]>
Cc Corey Ashford <[email protected]>
Cc David Ahern <[email protected]>
Cc Frederic Weisbecker <[email protected]>
Cc Ingo Molnar <[email protected]>
Cc Jean Pihet <[email protected]>
Cc Namhyung Kim <[email protected]>
Cc Paul Mackerras <[email protected]>
Cc Peter Zijlstra <[email protected]>
Link http://lkml.kernel.org/n/[email protected] open here
Signed-off-by Arnaldo Carvalho de Melo <[email protected]>
---
 tools/perf/util/ordered-events.c |  4 ++++
 tools/perf/util/ordered-events.h |  2 ++
 tools/perf/util/session.c        | 12 +++++++++---
 3 files changed, 15 insertions(+), 3 deletions(-)
tools/perf/util/ordered-events.c +4 -0
index 8a8aeab..706ce1a 100644
@@ -169,6 +169,7 @@ int ordered_events__flush(struct perf_session *s, struct perf_tool *tool,
 {
 	struct ordered_events *oe = &s->ordered_events;
 	static const char * const str[] = {
+		"NONE",
 		"FINAL",
 		"ROUND",
 		"HALF ",

@@ -198,6 +199,7 @@ int ordered_events__flush(struct perf_session *s, struct perf_tool *tool,
 	}
 
 	case OE_FLUSH__ROUND:
+	case OE_FLUSH__NONE:
 	default:
 		break;
 	};

@@ -211,6 +213,8 @@ int ordered_events__flush(struct perf_session *s, struct perf_tool *tool,
 	if (!err) {
 		if (how == OE_FLUSH__ROUND)
 			oe->next_flush = oe->max_timestamp;
+
+		oe->last_flush_type = how;
 	}
 
 	pr_oe_time(oe->next_flush, "next_flush - ordered_events__flush POST %s, nr_events %u\n",
tools/perf/util/ordered-events.h +2 -0
index 2ce847f..3b2f205 100644
@@ -14,6 +14,7 @@ struct ordered_event {
 };
 
 enum oe_flush {
+	OE_FLUSH__NONE,
 	OE_FLUSH__FINAL,
 	OE_FLUSH__ROUND,
 	OE_FLUSH__HALF,

@@ -32,6 +33,7 @@ struct ordered_events {
 	struct ordered_event	*last;
 	int			buffer_idx;
 	unsigned int		nr_events;
+	enum oe_flush		last_flush_type;
 };
 
 struct ordered_event *ordered_events__new(struct ordered_events *oe, u64 timestamp);
tools/perf/util/session.c +9 -3
index 462be27..7e27f1e 100644
@@ -14,6 +14,7 @@
 #include "util.h"
 #include "cpumap.h"
 #include "perf_regs.h"
+#include "asm/bug.h"
 
 static int perf_session__open(struct perf_session *session)
 {

@@ -500,10 +501,15 @@ int perf_session_queue_event(struct perf_session *s, union perf_event *event,
 		return -ETIME;
 
 	if (timestamp < oe->last_flush) {
-		printf("Warning: Timestamp below last timeslice flush\n");
+		WARN_ONCE(1, "Timestamp below last timeslice flush\n");
+
 		pr_oe_time(timestamp,      "out of order event");
-		pr_oe_time(oe->last_flush, "last flush");
-		return -EINVAL;
+		pr_oe_time(oe->last_flush, "last flush, last_flush_type %d\n",
+			   oe->last_flush_type);
+
+		/* We could get out of order messages after forced flush. */
+		if (oe->last_flush_type != OE_FLUSH__HALF)
+			return -EINVAL;
 	}
 
 	new = ordered_events__new(oe, timestamp);