[PATCH v2 3/5] perf tools: add core support for sampling intr machine state regs

From: Stephane Eranian
Date: Mon Jul 14 2014 - 20:32:30 EST


Add the infrastructure to setup, collect and report the interrupt
machine state regs which can be captured by the kernel.

Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>
---
tools/perf/perf.h | 1 +
tools/perf/util/event.h | 1 +
tools/perf/util/evsel.c | 46 ++++++++++++++++++++++++++++++++++++++++++++-
tools/perf/util/session.c | 44 ++++++++++++++++++++++++++++++++++++++-----
4 files changed, 86 insertions(+), 6 deletions(-)

diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 510c65f..309d956 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -54,6 +54,7 @@ struct record_opts {
bool sample_weight;
bool sample_time;
bool period;
+ bool sample_intr_regs;
unsigned int freq;
unsigned int mmap_pages;
unsigned int user_freq;
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index e5dd40a..4e36967 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -160,6 +160,7 @@ struct perf_sample {
struct ip_callchain *callchain;
struct branch_stack *branch_stack;
struct regs_dump user_regs;
+ struct regs_dump intr_regs;
struct stack_dump user_stack;
struct sample_read read;
};
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 8606175..2ba3403 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -626,6 +626,11 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
if (opts->call_graph_enabled)
perf_evsel__config_callgraph(evsel, opts);

+ if (opts->sample_intr_regs) {
+ attr->sample_regs_intr = PERF_REGS_MASK;
+ perf_evsel__set_sample_bit(evsel, REGS_INTR);
+ }
+
if (target__has_cpu(&opts->target))
perf_evsel__set_sample_bit(evsel, CPU);

@@ -979,6 +984,7 @@ static size_t perf_event_attr__fprintf(struct perf_event_attr *attr, FILE *fp)
ret += PRINT_ATTR_X64(branch_sample_type);
ret += PRINT_ATTR_X64(sample_regs_user);
ret += PRINT_ATTR_U32(sample_stack_user);
+ ret += PRINT_ATTR_X64(sample_regs_intr);

ret += fprintf(fp, "%.60s\n", graph_dotted_line);

@@ -1468,6 +1474,23 @@ int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event,
array++;
}

+ data->intr_regs.abi = PERF_SAMPLE_REGS_ABI_NONE;
+ if (type & PERF_SAMPLE_REGS_INTR) {
+ OVERFLOW_CHECK_u64(array);
+ data->intr_regs.abi = *array;
+ array++;
+
+ if (data->intr_regs.abi != PERF_SAMPLE_REGS_ABI_NONE) {
+ u64 mask = evsel->attr.sample_regs_intr;
+
+ sz = hweight_long(mask) * sizeof(u64);
+ OVERFLOW_CHECK(array, sz, max_size);
+ data->intr_regs.mask = mask;
+ data->intr_regs.regs = (u64 *)array;
+ array = (void *)array + sz;
+ }
+ }
+
return 0;
}

@@ -1563,6 +1586,16 @@ size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type,
if (type & PERF_SAMPLE_TRANSACTION)
result += sizeof(u64);

+ if (type & PERF_SAMPLE_REGS_INTR) {
+ if (sample->intr_regs.abi) {
+ result += sizeof(u64);
+ sz = hweight_long(sample->intr_regs.mask) * sizeof(u64);
+ result += sz;
+ } else {
+ result += sizeof(u64);
+ }
+ }
+
return result;
}

@@ -1741,6 +1774,17 @@ int perf_event__synthesize_sample(union perf_event *event, u64 type,
array++;
}

+ if (type & PERF_SAMPLE_REGS_INTR) {
+ if (sample->intr_regs.abi) {
+ *array++ = sample->intr_regs.abi;
+ sz = hweight_long(sample->intr_regs.mask) * sizeof(u64);
+ memcpy(array, sample->intr_regs.regs, sz);
+ array = (void *)array + sz;
+ } else {
+ *array++ = 0;
+ }
+ }
+
return 0;
}

@@ -1870,7 +1914,7 @@ static int sample_type__fprintf(FILE *fp, bool *first, u64 value)
bit_name(READ), bit_name(CALLCHAIN), bit_name(ID), bit_name(CPU),
bit_name(PERIOD), bit_name(STREAM_ID), bit_name(RAW),
bit_name(BRANCH_STACK), bit_name(REGS_USER), bit_name(STACK_USER),
- bit_name(IDENTIFIER),
+ bit_name(IDENTIFIER), bit_name(REGS_INTR),
{ .name = NULL, }
};
#undef bit_name
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 64a186e..9da3eda 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -702,15 +702,46 @@ static void regs_dump__printf(u64 mask, u64 *regs)
}
}

+static const char *regs_abi[]= {
+ [PERF_SAMPLE_REGS_ABI_NONE] = "none",
+ [PERF_SAMPLE_REGS_ABI_32] = "32-bit",
+ [PERF_SAMPLE_REGS_ABI_64] = "64-bit",
+};
+
+static inline const char *regs_dump_abi(struct regs_dump *d)
+{
+ if (d->abi > PERF_SAMPLE_REGS_ABI_64)
+ return "unknown";
+
+ return regs_abi[d->abi];
+}
+
+static void regs__printf(const char *type, struct regs_dump *regs)
+{
+ u64 mask = regs->mask;
+
+ printf("... %s regs: mask 0x%" PRIx64 " ABI %s\n",
+ type,
+ mask,
+ regs_dump_abi(regs));
+
+ regs_dump__printf(mask, regs->regs);
+}
+
static void regs_user__printf(struct perf_sample *sample)
{
struct regs_dump *user_regs = &sample->user_regs;

- if (user_regs->regs) {
- u64 mask = user_regs->mask;
- printf("... user regs: mask 0x%" PRIx64 "\n", mask);
- regs_dump__printf(mask, user_regs->regs);
- }
+ if (user_regs->regs)
+ regs__printf("user", user_regs);
+}
+
+static void regs_intr__printf(struct perf_sample *sample)
+{
+ struct regs_dump *intr_regs = &sample->intr_regs;
+
+ if (intr_regs->regs)
+ regs__printf("intr", intr_regs);
}

static void stack_user__printf(struct stack_dump *dump)
@@ -809,6 +840,9 @@ static void dump_sample(struct perf_evsel *evsel, union perf_event *event,
if (sample_type & PERF_SAMPLE_REGS_USER)
regs_user__printf(sample);

+ if (sample_type & PERF_SAMPLE_REGS_INTR)
+ regs_intr__printf(sample);
+
if (sample_type & PERF_SAMPLE_STACK_USER)
stack_user__printf(&sample->user_stack);

--
1.7.9.5

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