Hi Mathieu,
On 24/05/2019 18:34, Mathieu Poirier wrote:
When operating in CPU-wide mode being notified of contextID changes is required so that the decoding mechanic is aware of the process context switch.
Signed-off-by: Mathieu Poirier mathieu.poirier@linaro.org
Reviewed-by: Suzuki K Poulose suzuki.poulose@arm.com
I am sorry but, I don't remember reviewing this patch in the previous postings. But here we go.
tools/perf/arch/arm/util/cs-etm.c | 126 +++++++++++++++++++++++++----- tools/perf/util/cs-etm.h | 12 +++ 2 files changed, 119 insertions(+), 19 deletions(-)
diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c index 911426721170..3912f0bf04ed 100644 --- a/tools/perf/arch/arm/util/cs-etm.c +++ b/tools/perf/arch/arm/util/cs-etm.c @@ -35,8 +35,100 @@ struct cs_etm_recording { size_t snapshot_size; };
static bool cs_etm_is_etmv4(struct auxtrace_record *itr, int cpu); +static int cs_etm_set_context_id(struct auxtrace_record *itr,
struct perf_evsel *evsel, int cpu)+{
- struct cs_etm_recording *ptr;
- struct perf_pmu *cs_etm_pmu;
- char path[PATH_MAX];
- int err = -EINVAL;
- u32 val;
- ptr = container_of(itr, struct cs_etm_recording, itr);
- cs_etm_pmu = ptr->cs_etm_pmu;
- if (!cs_etm_is_etmv4(itr, cpu))
goto out;- /* Get a handle on TRCIRD2 */
- snprintf(path, PATH_MAX, "cpu%d/%s",
cpu, metadata_etmv4_ro[CS_ETMV4_TRCIDR2]);- err = perf_pmu__scan_file(cs_etm_pmu, path, "%x", &val);
- /* There was a problem reading the file, bailing out */
- if (err != 1) {
pr_err("%s: can't read file %s\n",CORESIGHT_ETM_PMU_NAME, path);goto out;- }
- /*
* TRCIDR2.CIDSIZE, bit [9-5], indicates whether contextID tracing* is supported:* 0b00000 Context ID tracing is not supported.* 0b00100 Maximum of 32-bit Context ID size.* All other values are reserved.*/- val = BMVAL(val, 5, 9);
- if (!val || val != 0x4) {
err = -EINVAL;goto out;- }
- /* All good, let the kernel know */
- evsel->attr.config |= (1 << ETM_OPT_CTXTID);
- err = 0;
+out:
- return err;
+}
+static int cs_etm_set_option(struct auxtrace_record *itr,
struct perf_evsel *evsel, u32 option)+{
- int i, err = -EINVAL;
- struct cpu_map *event_cpus = evsel->evlist->cpus;
- struct cpu_map *online_cpus = cpu_map__new(NULL);
- /* Set option of each CPU we have */
- for (i = 0; i < cpu__max_cpu(); i++) {
if (!cpu_map__has(event_cpus, i) ||!cpu_map__has(online_cpus, i))continue;switch (option) {case ETM_OPT_CTXTID:err = cs_etm_set_context_id(itr, evsel, i);if (err)goto out;break;default:goto out;}- }
I am not too familiar with the perf tool code. But, isn't there a way to force the config bit, right from the beginning when the events are created, when we know that we are doing a CPU wide tracing, along with the other config bits ?
- err = 0;
+out:
- cpu_map__put(online_cpus);
- return err;
+}
- static int cs_etm_parse_snapshot_options(struct auxtrace_record *itr, struct record_opts *opts, const char *str)
@@ -105,8 +197,9 @@ static int cs_etm_recording_options(struct auxtrace_record *itr, container_of(itr, struct cs_etm_recording, itr); struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu; struct perf_evsel *evsel, *cs_etm_evsel = NULL;
- const struct cpu_map *cpus = evlist->cpus;
- struct cpu_map *cpus = evlist->cpus; bool privileged = (geteuid() == 0 || perf_event_paranoid() < 0);
- int err = 0;
ptr->evlist = evlist; ptr->snapshot_mode = opts->auxtrace_snapshot_mode; @@ -241,19 +334,24 @@ static int cs_etm_recording_options(struct auxtrace_record *itr, /* * In the case of per-cpu mmaps, we need the CPU on the
* AUX event.
* AUX event. We also need the contextID in order to be notified* when a context switch happened.
- if (!cpu_map__empty(cpus))
- if (!cpu_map__empty(cpus)) { perf_evsel__set_sample_bit(cs_etm_evsel, CPU);
err = cs_etm_set_option(itr, cs_etm_evsel, ETM_OPT_CTXTID);if (err)goto out;- }
- /* Add dummy event to keep tracking */ if (opts->full_auxtrace) { struct perf_evsel *tracking_evsel;
int err;err = parse_events(evlist, "dummy:u", NULL); if (err)
return err;
goto out;tracking_evsel = perf_evlist__last(evlist); perf_evlist__set_tracking_event(evlist, tracking_evsel); @@ -266,7 +364,8 @@ static int cs_etm_recording_options(struct auxtrace_record *itr, perf_evsel__set_sample_bit(tracking_evsel, TIME); }
- return 0;
+out:
- return err; }
diff --git a/tools/perf/util/cs-etm.h b/tools/perf/util/cs-etm.h index 0e97c196147a..826c9eedaf5c 100644 --- a/tools/perf/util/cs-etm.h +++ b/tools/perf/util/cs-etm.h @@ -103,6 +103,18 @@ struct intlist *traceid_list; #define KiB(x) ((x) * 1024) #define MiB(x) ((x) * 1024 * 1024) +/*
- Create a contiguous bitmask starting at bit position @l and ending at
- position @h. For example
- GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
- Carbon copy of implementation found in $KERNEL/include/linux/bitops.h
- */
+#define GENMASK(h, l) \
- (((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
minor nit: Could this be placed in a more generic header file for the other parts of the perf tool to consume ?
+#define BMVAL(val, lsb, msb) ((val & GENMASK(msb, lsb)) >> lsb)
Cheers Suzuki