[PATCH 01/12] perf auxtrace: Add Z itrace option for timeless decoding

From: Adrian Hunter <adrian.hunter@intel.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Jiri Olsa <jolsa@redhat.com>, Andi Kleen <ak@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH 01/12] perf auxtrace: Add Z itrace option for timeless decoding
Date: Thu, 29 Apr 2021 15:58:43 +0300	[thread overview]
Message-ID: <20210429125854.13905-2-adrian.hunter@intel.com> (raw)
In-Reply-To: <20210429125854.13905-1-adrian.hunter@intel.com>

Issues correlating timestamps can be avoided with timeless decoding. Add
an option for that, so that timeless decoding can be used even when
timestamps are present.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 tools/perf/Documentation/itrace.txt | 1 +
 tools/perf/util/auxtrace.c          | 3 +++
 tools/perf/util/auxtrace.h          | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/tools/perf/Documentation/itrace.txt b/tools/perf/Documentation/itrace.txt
index 0f1005209a2b..2d586fe5e4c5 100644
--- a/tools/perf/Documentation/itrace.txt
+++ b/tools/perf/Documentation/itrace.txt
@@ -20,6 +20,7 @@
 		L	synthesize last branch entries on existing event records
 		s       skip initial number of events
 		q	quicker (less detailed) decoding
+		Z	prefer to ignore timestamps (so-called "timeless" decoding)
 
 	The default is all events i.e. the same as --itrace=ibxwpe,
 	except for perf script where it is --itrace=ce
diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
index 5b6ccb90b397..48b88e2bca1e 100644
--- a/tools/perf/util/auxtrace.c
+++ b/tools/perf/util/auxtrace.c
@@ -1569,6 +1569,9 @@ int itrace_parse_synth_opts(const struct option *opt, const char *str,
 		case 'q':
 			synth_opts->quick += 1;
 			break;
+		case 'Z':
+			synth_opts->timeless_decoding = true;
+			break;
 		case ' ':
 		case ',':
 			break;
diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h
index a4fbb33b7245..59c3c05384a4 100644
--- a/tools/perf/util/auxtrace.h
+++ b/tools/perf/util/auxtrace.h
@@ -89,6 +89,7 @@ enum itrace_period_type {
  * @tlb: whether to synthesize TLB events
  * @remote_access: whether to synthesize remote access events
  * @mem: whether to synthesize memory events
+ * @timeless_decoding: prefer "timeless" decoding i.e. ignore timestamps
  * @callchain_sz: maximum callchain size
  * @last_branch_sz: branch context size
  * @period: 'instructions' events period
@@ -128,6 +129,7 @@ struct itrace_synth_opts {
 	bool			tlb;
 	bool			remote_access;
 	bool			mem;
+	bool			timeless_decoding;
 	unsigned int		callchain_sz;
 	unsigned int		last_branch_sz;
 	unsigned long long	period;
-- 
2.17.1

