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Message-Id: <1437150840-31811-18-git-send-email-adrian.hunter@intel.com>
Date: Fri, 17 Jul 2015 19:33:52 +0300
From: Adrian Hunter <adrian.hunter@...el.com>
To: Arnaldo Carvalho de Melo <acme@...nel.org>
Cc: Ingo Molnar <mingo@...nel.org>, linux-kernel@...r.kernel.org,
Jiri Olsa <jolsa@...hat.com>
Subject: [PATCH V8 17/25] perf tools: Add Intel PT support for PSB periods
The PSB packet is a synchronization packet that
provides a starting point for decoding or recovery
from errors.
This patch adds support for a new Intel PT feature
that allows the frequency of PSB packets to be specified.
Support for this feature is indicated by
/sys/bus/event_source/devices/intel_pt/caps/psb_cyc
which contains "1" if the feature is supported and
"0" otherwise.
The PSB period can be specified as a PMU config term
e.g. perf record -e intel_pt/psb_period=2/u sleep 1
The default value is 3 or the nearest lower value
that is supported. 0 is always supported.
Valid values are given by:
/sys/bus/event_source/devices/intel_pt/caps/psb_periods
which contains a hexadecimal value, the bits of which
represent valid values e.g. bit 2 set means value 2
is valid.
The value is converted to the approximate number of
trace bytes between PSB packets as:
2 ^ (value + 11)
e.g. value 3 means 16KiB bytes between PSBs
If an invalid value is entered, the error message
will give a list of valid values e.g.
$ perf record -e intel_pt/psb_period=15/u uname
Invalid psb_period for intel_pt. Valid values are: 0-5
tools/perf/Documentation/intel-pt.txt is updated in
a later patch as there are a number of new features
being added.
For more information about PSB periods refer to the
Intel 64 and IA-32 Architectures SDM Chapter 36
Intel Processor Trace from June 2015 or later.
Signed-off-by: Adrian Hunter <adrian.hunter@...el.com>
---
tools/perf/arch/x86/util/intel-pt.c | 217 ++++++++++++++++++++++++++++++++++--
1 file changed, 210 insertions(+), 7 deletions(-)
diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c
index da7d2c15e611..145975b003a7 100644
--- a/tools/perf/arch/x86/util/intel-pt.c
+++ b/tools/perf/arch/x86/util/intel-pt.c
@@ -99,17 +99,121 @@ static int intel_pt_parse_terms(struct list_head *formats, const char *str,
return intel_pt_parse_terms_with_default(formats, str, config);
}
-static size_t intel_pt_psb_period(struct perf_pmu *intel_pt_pmu __maybe_unused,
- struct perf_evlist *evlist __maybe_unused)
+static u64 intel_pt_masked_bits(u64 mask, u64 bits)
{
- return 256;
+ const u64 top_bit = 1ULL << 63;
+ u64 res = 0;
+ int i;
+
+ for (i = 0; i < 64; i++) {
+ if (mask & top_bit) {
+ res <<= 1;
+ if (bits & top_bit)
+ res |= 1;
+ }
+ mask <<= 1;
+ bits <<= 1;
+ }
+
+ return res;
+}
+
+static int intel_pt_read_config(struct perf_pmu *intel_pt_pmu, const char *str,
+ struct perf_evlist *evlist, u64 *res)
+{
+ struct perf_evsel *evsel;
+ u64 mask;
+
+ *res = 0;
+
+ mask = perf_pmu__format_bits(&intel_pt_pmu->format, str);
+ if (!mask)
+ return -EINVAL;
+
+ evlist__for_each(evlist, evsel) {
+ if (evsel->attr.type == intel_pt_pmu->type) {
+ *res = intel_pt_masked_bits(mask, evsel->attr.config);
+ return 0;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static size_t intel_pt_psb_period(struct perf_pmu *intel_pt_pmu,
+ struct perf_evlist *evlist)
+{
+ u64 val;
+ int err, topa_multiple_entries;
+ size_t psb_period;
+
+ if (perf_pmu__scan_file(intel_pt_pmu, "caps/topa_multiple_entries",
+ "%d", &topa_multiple_entries) != 1)
+ topa_multiple_entries = 0;
+
+ /*
+ * Use caps/topa_multiple_entries to indicate early hardware that had
+ * extra frequent PSBs.
+ */
+ if (!topa_multiple_entries) {
+ psb_period = 256;
+ goto out;
+ }
+
+ err = intel_pt_read_config(intel_pt_pmu, "psb_period", evlist, &val);
+ if (err)
+ val = 0;
+
+ psb_period = 1 << (val + 11);
+out:
+ pr_debug2("%s psb_period %zu\n", intel_pt_pmu->name, psb_period);
+ return psb_period;
+}
+
+static int intel_pt_pick_bit(int bits, int target)
+{
+ int pos, pick = -1;
+
+ for (pos = 0; bits; bits >>= 1, pos++) {
+ if (bits & 1) {
+ if (pos <= target || pick < 0)
+ pick = pos;
+ if (pos >= target)
+ break;
+ }
+ }
+
+ return pick;
}
static u64 intel_pt_default_config(struct perf_pmu *intel_pt_pmu)
{
+ char buf[256];
+ int psb_cyc, psb_periods, psb_period;
+ int pos = 0;
u64 config;
- intel_pt_parse_terms(&intel_pt_pmu->format, "tsc", &config);
+ pos += scnprintf(buf + pos, sizeof(buf) - pos, "tsc");
+
+ if (perf_pmu__scan_file(intel_pt_pmu, "caps/psb_cyc", "%d",
+ &psb_cyc) != 1)
+ psb_cyc = 1;
+
+ if (psb_cyc) {
+ if (perf_pmu__scan_file(intel_pt_pmu, "caps/psb_periods", "%x",
+ &psb_periods) != 1)
+ psb_periods = 0;
+ if (psb_periods) {
+ psb_period = intel_pt_pick_bit(psb_periods, 3);
+ pos += scnprintf(buf + pos, sizeof(buf) - pos,
+ ",psb_period=%d", psb_period);
+ }
+ }
+
+ pr_debug2("%s default config: %s\n", intel_pt_pmu->name, buf);
+
+ intel_pt_parse_terms(&intel_pt_pmu->format, buf, &config);
+
return config;
}
@@ -239,6 +343,103 @@ static int intel_pt_track_switches(struct perf_evlist *evlist)
return 0;
}
+static void intel_pt_valid_str(char *str, size_t len, u64 valid)
+{
+ unsigned int val, last = 0, state = 1;
+ int p = 0;
+
+ str[0] = '\0';
+
+ for (val = 0; val <= 64; val++, valid >>= 1) {
+ if (valid & 1) {
+ last = val;
+ switch (state) {
+ case 0:
+ p += scnprintf(str + p, len - p, ",");
+ /* Fall through */
+ case 1:
+ p += scnprintf(str + p, len - p, "%u", val);
+ state = 2;
+ break;
+ case 2:
+ state = 3;
+ break;
+ case 3:
+ state = 4;
+ break;
+ default:
+ break;
+ }
+ } else {
+ switch (state) {
+ case 3:
+ p += scnprintf(str + p, len - p, ",%u", last);
+ state = 0;
+ break;
+ case 4:
+ p += scnprintf(str + p, len - p, "-%u", last);
+ state = 0;
+ break;
+ default:
+ break;
+ }
+ if (state != 1)
+ state = 0;
+ }
+ }
+}
+
+static int intel_pt_val_config_term(struct perf_pmu *intel_pt_pmu,
+ const char *caps, const char *name,
+ const char *supported, u64 config)
+{
+ char valid_str[256];
+ unsigned int shift;
+ unsigned long long valid;
+ u64 bits;
+ int ok;
+
+ if (perf_pmu__scan_file(intel_pt_pmu, caps, "%llx", &valid) != 1)
+ valid = 0;
+
+ if (supported &&
+ perf_pmu__scan_file(intel_pt_pmu, supported, "%d", &ok) == 1 && !ok)
+ valid = 0;
+
+ valid |= 1;
+
+ bits = perf_pmu__format_bits(&intel_pt_pmu->format, name);
+
+ config &= bits;
+
+ for (shift = 0; bits && !(bits & 1); shift++)
+ bits >>= 1;
+
+ config >>= shift;
+
+ if (config > 63)
+ goto out_err;
+
+ if (valid & (1 << config))
+ return 0;
+out_err:
+ intel_pt_valid_str(valid_str, sizeof(valid_str), valid);
+ pr_err("Invalid %s for %s. Valid values are: %s\n",
+ name, INTEL_PT_PMU_NAME, valid_str);
+ return -EINVAL;
+}
+
+static int intel_pt_validate_config(struct perf_pmu *intel_pt_pmu,
+ struct perf_evsel *evsel)
+{
+ if (!evsel)
+ return 0;
+
+ return intel_pt_val_config_term(intel_pt_pmu, "caps/psb_periods",
+ "psb_period", "caps/psb_cyc",
+ evsel->attr.config);
+}
+
static int intel_pt_recording_options(struct auxtrace_record *itr,
struct perf_evlist *evlist,
struct record_opts *opts)
@@ -251,6 +452,7 @@ static int intel_pt_recording_options(struct auxtrace_record *itr,
const struct cpu_map *cpus = evlist->cpus;
bool privileged = geteuid() == 0 || perf_event_paranoid() < 0;
u64 tsc_bit;
+ int err;
ptr->evlist = evlist;
ptr->snapshot_mode = opts->auxtrace_snapshot_mode;
@@ -281,6 +483,10 @@ static int intel_pt_recording_options(struct auxtrace_record *itr,
if (!opts->full_auxtrace)
return 0;
+ err = intel_pt_validate_config(intel_pt_pmu, intel_pt_evsel);
+ if (err)
+ return err;
+
/* Set default sizes for snapshot mode */
if (opts->auxtrace_snapshot_mode) {
size_t psb_period = intel_pt_psb_period(intel_pt_pmu, evlist);
@@ -366,8 +572,6 @@ static int intel_pt_recording_options(struct auxtrace_record *itr,
* threads.
*/
if (have_timing_info && !cpu_map__empty(cpus)) {
- int err;
-
err = intel_pt_track_switches(evlist);
if (err == -EPERM)
pr_debug2("Unable to select sched:sched_switch\n");
@@ -394,7 +598,6 @@ static int intel_pt_recording_options(struct auxtrace_record *itr,
/* 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)
--
1.9.1
--
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