[PATCH] perf, tools, pmu-events: Fix fixed counters on Intel

[PATCH] perf, tools, pmu-events: Fix fixed counters on Intel

[Andi Kleen]

From: Andi Kleen <ak@linux.intel.com>

[This patch is on top of Sukadev's json patchkit]

The JSON event lists use a different encoding for fixed counters
than perf for instructions and cycles (ref-cycles is ok)

This lead to some common events like inst_retired.any
or cpu_clk_unhalted.thread not counting, when specified with their
JSON name.

Special case these events in the jevents conversion process.
I prefer to not touch the JSON files for this, as it's intended
that standard JSON files can be just dropped into the perf
build without changes.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 tools/perf/pmu-events/jevents.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/tools/perf/pmu-events/jevents.c b/tools/perf/pmu-events/jevents.c
index 7347cca..f4e5903 100644
--- a/tools/perf/pmu-events/jevents.c
+++ b/tools/perf/pmu-events/jevents.c
@@ -237,6 +237,28 @@ static void print_events_table_suffix(FILE *outfp)
 	fprintf(outfp, "};\n");
 }
 
+static struct fixed {
+	const char *name;
+	const char *event;
+} fixed[] = {
+	{ "inst_retired.any", "event=0xc0" },
+	{ "cpu_clk_unhalted.thread", "event=0x3c" },
+	{ "cpu_clk_unhalted.thread_any", "event=0x3c,any=1" },
+	{},
+};
+
+/*
+ * Handle different fixed counter encodings between JSON and perf.
+ */
+static char *real_event(const char *name, char *event)
+{
+	int i;
+	for (i = 0; fixed[i].name; i++)
+		if (!strcasecmp(name, fixed[i].name))
+			return (char *)fixed[i].event;
+	return event;
+}
+
 /* Call func with each event in the json file */
 int json_events(const char *fn,
 	  int (*func)(void *data, char *name, char *event, char *desc,
@@ -324,8 +346,7 @@ int json_events(const char *fn,
 		if (msr != NULL)
 			addfield(map, &event, ",", msr->pname, msrval);
 		fixname(name);
-
-		err = func(data, name, event, desc, long_desc, topic);
+		err = func(data, name, real_event(name, event), desc, long_desc, topic);
 		free(event);
 		free(desc);
 		free(name);
-- 
2.4.3

Re: [PATCH] perf, tools, pmu-events: Fix fixed counters on Intel

[Sukadev Bhattiprolu]

Andi,

Andi Kleen [andi@firstfloor.org] wrote:
| From: Andi Kleen <ak@linux.intel.com>
| 
| [This patch is on top of Sukadev's json patchkit]

I removed this line from the commit log...

| 
| The JSON event lists use a different encoding for fixed counters
| than perf for instructions and cycles (ref-cycles is ok)
| 
| This lead to some common events like inst_retired.any
| or cpu_clk_unhalted.thread not counting, when specified with their
| JSON name.
| 
| Special case these events in the jevents conversion process.
| I prefer to not touch the JSON files for this, as it's intended
| that standard JSON files can be just dropped into the perf
| build without changes.
| 
| Signed-off-by: Andi Kleen <ak@linux.intel.com>
| ---
|  tools/perf/pmu-events/jevents.c | 25 +++++++++++++++++++++++--
|  1 file changed, 23 insertions(+), 2 deletions(-)
| 
| diff --git a/tools/perf/pmu-events/jevents.c b/tools/perf/pmu-events/jevents.c
| index 7347cca..f4e5903 100644
| --- a/tools/perf/pmu-events/jevents.c
| +++ b/tools/perf/pmu-events/jevents.c
| @@ -237,6 +237,28 @@ static void print_events_table_suffix(FILE *outfp)
|  	fprintf(outfp, "};\n");
|  }
| 
| +static struct fixed {
| +	const char *name;
| +	const char *event;
| +} fixed[] = {
| +	{ "inst_retired.any", "event=0xc0" },
| +	{ "cpu_clk_unhalted.thread", "event=0x3c" },
| +	{ "cpu_clk_unhalted.thread_any", "event=0x3c,any=1" },
| +	{},

...and replaced this line with:

	{NULL, NULL},

to fix the compile error:

pmu-events/jevents.c:247:2: error: missing initializer for field ‘name’ of ‘struct fixed’ [-Werror=missing-field-initializers]
  {},

After this I was able to get non-zero counts for the 'inst_retired.any'
event on my system. Without the patch, I get 0 count for the event.

I pushed this commit to the 'json-v16' branch.

I also noticed an "Unknown MSR" message when building 'jevents':

  CC       /root/suka/linux-acme.git/tools/perf/perf-obj/pmu-events/jevents.o
  LD       /root/suka/linux-acme.git/tools/perf/perf-obj/pmu-events/jevents-in.o
  LINK     /root/suka/linux-acme.git/tools/perf/perf-obj/pmu-events/jevents
  GEN      /root/suka/linux-acme.git/tools/perf/perf-obj/pmu-events/pmu-events.c
jevents: Unknown MSR in event file 0x3F7

The message is unrelated to the current patch and seems to show up when
processing:

	tools/perf/pmu-events/arch/x86/Skylake_core.json

(Note that you have to merge the 'json-files-7' branch with 'json-v16' to get
the JSON files and hence the error).

Thanks,

Sukadev

Re: [PATCH] perf, tools, pmu-events: Fix fixed counters on Intel

[Andi Kleen]

> 
> pmu-events/jevents.c:247:2: error: missing initializer for field ‘name’ of ‘struct fixed’ [-Werror=missing-field-initializers]

Thanks.

Somehow a WERROR=0 must have slipped into the build script again.


> After this I was able to get non-zero counts for the 'inst_retired.any'
> event on my system. Without the patch, I get 0 count for the event.
> 
> I pushed this commit to the 'json-v16' branch.
> 
> I also noticed an "Unknown MSR" message when building 'jevents':
> 
>   CC       /root/suka/linux-acme.git/tools/perf/perf-obj/pmu-events/jevents.o
>   LD       /root/suka/linux-acme.git/tools/perf/perf-obj/pmu-events/jevents-in.o
>   LINK     /root/suka/linux-acme.git/tools/perf/perf-obj/pmu-events/jevents
>   GEN      /root/suka/linux-acme.git/tools/perf/perf-obj/pmu-events/pmu-events.c
> jevents: Unknown MSR in event file 0x3F7

I'll take a look and send a patch for that.

-Andi