linux-kernel - [PATCH 01/25] perf auxtrace: Fix 'instructions' period of zero

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1443186956-18718-2-git-send-email-adrian.hunter@intel.com>
Date:	Fri, 25 Sep 2015 16:15:32 +0300
From:	Adrian Hunter <adrian.hunter@...el.com>
To:	Arnaldo Carvalho de Melo <acme@...nel.org>
Cc:	Jiri Olsa <jolsa@...hat.com>, linux-kernel@...r.kernel.org
Subject: [PATCH 01/25] perf auxtrace: Fix 'instructions' period of zero

Instruction tracing options (i.e. --itrace) include an option for
sampling instructions at an arbitrary period. e.g.

	--itrace=i10us

means make an 'instructions' sample for every 10us of trace.

Currently the logic does not distinguish between a period of
zero and no period being specified at all, so it gets treated
as the default period which is 100000.  That doesn't really
make sense.

Fix it so that zero period is accepted and treated as meaning
"as often as possible".

In the case of Intel PT that is the same as a period of 1 and
a unit of 'instructions' (i.e. --itrace=i1i).

Signed-off-by: Adrian Hunter <adrian.hunter@...el.com>
---
 tools/perf/util/auxtrace.c | 4 +++-
 tools/perf/util/intel-pt.c | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
index a980e7c50ee0..c4993b2e6c50 100644
--- a/tools/perf/util/auxtrace.c
+++ b/tools/perf/util/auxtrace.c
@@ -950,6 +950,7 @@ int itrace_parse_synth_opts(const struct option *opt, const char *str,
 	const char *p;
 	char *endptr;
 	bool period_type_set = false;
+	bool period_set = false;
 
 	synth_opts->set = true;
 
@@ -971,6 +972,7 @@ int itrace_parse_synth_opts(const struct option *opt, const char *str,
 				p += 1;
 			if (isdigit(*p)) {
 				synth_opts->period = strtoull(p, &endptr, 10);
+				period_set = true;
 				p = endptr;
 				while (*p == ' ' || *p == ',')
 					p += 1;
@@ -1053,7 +1055,7 @@ out:
 		if (!period_type_set)
 			synth_opts->period_type =
 					PERF_ITRACE_DEFAULT_PERIOD_TYPE;
-		if (!synth_opts->period)
+		if (!period_set)
 			synth_opts->period = PERF_ITRACE_DEFAULT_PERIOD;
 	}
 
diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
index 38942e1eac8f..c8bb5ca6a157 100644
--- a/tools/perf/util/intel-pt.c
+++ b/tools/perf/util/intel-pt.c
@@ -720,7 +720,7 @@ static struct intel_pt_queue *intel_pt_alloc_queue(struct intel_pt *pt,
 
 		if (!params.period) {
 			params.period_type = INTEL_PT_PERIOD_INSTRUCTIONS;
-			params.period = 1000;
+			params.period = 1;
 		}
 	}
 
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/