[PATCH 24/53] perf arm cs-etm: Use event attributes to send sink information to kernel

From: Arnaldo Carvalho de Melo <acme@kernel•org>
To: Ingo Molnar <mingo@kernel•org>
Cc: Mark Rutland <mark.rutland@arm•com>,
	Clark Williams <williams@redhat•com>,
	Heiko Carstens <heiko.carstens@de•ibm.com>,
	Alexei Starovoitov <ast@kernel•org>,
	Adrian Hunter <adrian.hunter@intel•com>,
	"H . Peter Anvin" <hpa@zytor•com>, Jiri Olsa <jolsa@redhat•com>,
	linux-s390@vger•kernel.org,
	Alexander Shishkin <alexander.shishkin@linux•intel.com>,
	Suzuki K Poulouse <suzuki.poulose@arm•com>,
	Will Deacon <will.deacon@arm•com>,
	Arnaldo Carvalho de Melo <acme@redhat•com>,
	Namhyung Kim <namhyung@kernel•org>,
	Thomas Gleixner <tglx@linutronix•de>,
	linux-arm-kernel@lists•infradead.org,
	Mathieu Poirier <mathieu.poirier@linaro•org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation•org>,
	linux-kernel@vger•kernel.org, linux-perf-users@vger•kernel.org,
	Peter Zijlstra <peterz@infradead•org>,
	Jiri Olsa <jolsa@kernel•org>,
	Martin Schwidefsky <schwidefsky@de•ibm.com>
Subject: [PATCH 24/53] perf arm cs-etm: Use event attributes to send sink information to kernel
Date: Wed,  6 Feb 2019 15:48:34 -0300	[thread overview]
Message-ID: <20190206184903.24054-25-acme@kernel.org> (raw)
In-Reply-To: <20190206184903.24054-1-acme@kernel.org>

From: Mathieu Poirier <mathieu.poirier@linaro•org>

The communication of sink information for a trace session doesn't work
when more than on CPU is involved in the scenario due to the static
nature of sysfs.  As such communicate the sink information to each event
by using the perf_event::attr:config2 attribute.  The information sent
to the kernel is an hash of the sink's name, which is unique in a
system.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro•org>
Acked-by: Suzuki K Poulouse <suzuki.poulose@arm•com>
Cc: Adrian Hunter <adrian.hunter@intel•com>
Cc: Alexander Shishkin <alexander.shishkin@linux•intel.com>
Cc: Alexei Starovoitov <ast@kernel•org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation•org>
Cc: H. Peter Anvin <hpa@zytor•com>
Cc: Heiko Carstens <heiko.carstens@de•ibm.com>
Cc: Jiri Olsa <jolsa@redhat•com>
Cc: Mark Rutland <mark.rutland@arm•com>
Cc: Martin Schwidefsky <schwidefsky@de•ibm.com>
Cc: Namhyung Kim <namhyung@kernel•org>
Cc: Peter Zijlstra <peterz@infradead•org>
Cc: Thomas Gleixner <tglx@linutronix•de>
Cc: Will Deacon <will.deacon@arm•com>
Cc: linux-arm-kernel@lists•infradead.org
Cc: linux-s390@vger•kernel.org
Link: http://lkml.kernel.org/r/20190131184714.20388-6-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat•com>
---
 tools/perf/arch/arm/util/cs-etm.c | 44 +++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
index 2f595cd73da6..4f31cf0d1e6d 100644
--- a/tools/perf/arch/arm/util/cs-etm.c
+++ b/tools/perf/arch/arm/util/cs-etm.c
@@ -5,6 +5,7 @@
  */
 
 #include <api/fs/fs.h>
+#include <linux/bits.h>
 #include <linux/bitops.h>
 #include <linux/compiler.h>
 #include <linux/coresight-pmu.h>
@@ -22,6 +23,7 @@
 #include "../../util/thread_map.h"
 #include "../../util/cs-etm.h"
 
+#include <errno.h>
 #include <stdlib.h>
 #include <sys/stat.h>
 
@@ -60,10 +62,48 @@ static int cs_etm_parse_snapshot_options(struct auxtrace_record *itr,
 	return 0;
 }
 
+static int cs_etm_set_sink_attr(struct perf_pmu *pmu,
+				struct perf_evsel *evsel)
+{
+	char msg[BUFSIZ], path[PATH_MAX], *sink;
+	struct perf_evsel_config_term *term;
+	int ret = -EINVAL;
+	u32 hash;
+
+	if (evsel->attr.config2 & GENMASK(31, 0))
+		return 0;
+
+	list_for_each_entry(term, &evsel->config_terms, list) {
+		if (term->type != PERF_EVSEL__CONFIG_TERM_DRV_CFG)
+			continue;
+
+		sink = term->val.drv_cfg;
+		snprintf(path, PATH_MAX, "sinks/%s", sink);
+
+		ret = perf_pmu__scan_file(pmu, path, "%x", &hash);
+		if (ret != 1) {
+			pr_err("failed to set sink \"%s\" on event %s with %d (%s)\n",
+			       sink, perf_evsel__name(evsel), errno,
+			       str_error_r(errno, msg, sizeof(msg)));
+			return ret;
+		}
+
+		evsel->attr.config2 |= hash;
+		return 0;
+	}
+
+	/*
+	 * No sink was provided on the command line - for _now_ treat
+	 * this as an error.
+	 */
+	return ret;
+}
+
 static int cs_etm_recording_options(struct auxtrace_record *itr,
 				    struct perf_evlist *evlist,
 				    struct record_opts *opts)
 {
+	int ret;
 	struct cs_etm_recording *ptr =
 				container_of(itr, struct cs_etm_recording, itr);
 	struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
@@ -92,6 +132,10 @@ static int cs_etm_recording_options(struct auxtrace_record *itr,
 	if (!cs_etm_evsel)
 		return 0;
 
+	ret = cs_etm_set_sink_attr(cs_etm_pmu, cs_etm_evsel);
+	if (ret)
+		return ret;
+
 	if (opts->use_clockid) {
 		pr_err("Cannot use clockid (-k option) with %s\n",
 		       CORESIGHT_ETM_PMU_NAME);
-- 
2.20.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists•infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
