summaryrefslogtreecommitdiff
path: root/tools/lib/perf
diff options
context:
space:
mode:
authorNamhyung Kim <namhyung@kernel.org>2022-08-19 03:36:42 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2022-08-19 21:56:27 +0300
commit89e3106fa25fb1b626a7123dba870159d453e785 (patch)
tree479a3e263e2c45941b75278480fa07d0c51e2938 /tools/lib/perf
parent65ba872a6971c11ceb342c3330f059289c0e6bdb (diff)
downloadlinux-89e3106fa25fb1b626a7123dba870159d453e785.tar.xz
libperf: Handle read format in perf_evsel__read()
The perf_counts_values should be increased to read the new lost data. Also adjust values after read according the read format. This supports PERF_FORMAT_GROUP which has a different data format but it's only available for leader events. Currently it doesn't have an API to read sibling (member) events in the group. But users may read the sibling event directly. Also reading from mmap would be disabled when the read format has ID or LOST bit as it's not exposed via mmap. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20220819003644.508916-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/lib/perf')
-rw-r--r--tools/lib/perf/evsel.c79
-rw-r--r--tools/lib/perf/include/perf/event.h3
-rw-r--r--tools/lib/perf/include/perf/evsel.h4
3 files changed, 83 insertions, 3 deletions
diff --git a/tools/lib/perf/evsel.c b/tools/lib/perf/evsel.c
index 952f3520d5c2..8ce5bbd09666 100644
--- a/tools/lib/perf/evsel.c
+++ b/tools/lib/perf/evsel.c
@@ -305,6 +305,9 @@ int perf_evsel__read_size(struct perf_evsel *evsel)
if (read_format & PERF_FORMAT_ID)
entry += sizeof(u64);
+ if (read_format & PERF_FORMAT_LOST)
+ entry += sizeof(u64);
+
if (read_format & PERF_FORMAT_GROUP) {
nr = evsel->nr_members;
size += sizeof(u64);
@@ -314,24 +317,98 @@ int perf_evsel__read_size(struct perf_evsel *evsel)
return size;
}
+/* This only reads values for the leader */
+static int perf_evsel__read_group(struct perf_evsel *evsel, int cpu_map_idx,
+ int thread, struct perf_counts_values *count)
+{
+ size_t size = perf_evsel__read_size(evsel);
+ int *fd = FD(evsel, cpu_map_idx, thread);
+ u64 read_format = evsel->attr.read_format;
+ u64 *data;
+ int idx = 1;
+
+ if (fd == NULL || *fd < 0)
+ return -EINVAL;
+
+ data = calloc(1, size);
+ if (data == NULL)
+ return -ENOMEM;
+
+ if (readn(*fd, data, size) <= 0) {
+ free(data);
+ return -errno;
+ }
+
+ /*
+ * This reads only the leader event intentionally since we don't have
+ * perf counts values for sibling events.
+ */
+ if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+ count->ena = data[idx++];
+ if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+ count->run = data[idx++];
+
+ /* value is always available */
+ count->val = data[idx++];
+ if (read_format & PERF_FORMAT_ID)
+ count->id = data[idx++];
+ if (read_format & PERF_FORMAT_LOST)
+ count->lost = data[idx++];
+
+ free(data);
+ return 0;
+}
+
+/*
+ * The perf read format is very flexible. It needs to set the proper
+ * values according to the read format.
+ */
+static void perf_evsel__adjust_values(struct perf_evsel *evsel, u64 *buf,
+ struct perf_counts_values *count)
+{
+ u64 read_format = evsel->attr.read_format;
+ int n = 0;
+
+ count->val = buf[n++];
+
+ if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+ count->ena = buf[n++];
+
+ if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+ count->run = buf[n++];
+
+ if (read_format & PERF_FORMAT_ID)
+ count->id = buf[n++];
+
+ if (read_format & PERF_FORMAT_LOST)
+ count->lost = buf[n++];
+}
+
int perf_evsel__read(struct perf_evsel *evsel, int cpu_map_idx, int thread,
struct perf_counts_values *count)
{
size_t size = perf_evsel__read_size(evsel);
int *fd = FD(evsel, cpu_map_idx, thread);
+ u64 read_format = evsel->attr.read_format;
+ struct perf_counts_values buf;
memset(count, 0, sizeof(*count));
if (fd == NULL || *fd < 0)
return -EINVAL;
+ if (read_format & PERF_FORMAT_GROUP)
+ return perf_evsel__read_group(evsel, cpu_map_idx, thread, count);
+
if (MMAP(evsel, cpu_map_idx, thread) &&
+ !(read_format & (PERF_FORMAT_ID | PERF_FORMAT_LOST)) &&
!perf_mmap__read_self(MMAP(evsel, cpu_map_idx, thread), count))
return 0;
- if (readn(*fd, count->values, size) <= 0)
+ if (readn(*fd, buf.values, size) <= 0)
return -errno;
+ perf_evsel__adjust_values(evsel, buf.values, count);
return 0;
}
diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h
index 57f54781f5ed..93bf93a59c99 100644
--- a/tools/lib/perf/include/perf/event.h
+++ b/tools/lib/perf/include/perf/event.h
@@ -77,7 +77,7 @@ struct perf_record_lost_samples {
};
/*
- * PERF_FORMAT_ENABLED | PERF_FORMAT_RUNNING | PERF_FORMAT_ID
+ * PERF_FORMAT_ENABLED | PERF_FORMAT_RUNNING | PERF_FORMAT_ID | PERF_FORMAT_LOST
*/
struct perf_record_read {
struct perf_event_header header;
@@ -86,6 +86,7 @@ struct perf_record_read {
__u64 time_enabled;
__u64 time_running;
__u64 id;
+ __u64 lost;
};
struct perf_record_throttle {
diff --git a/tools/lib/perf/include/perf/evsel.h b/tools/lib/perf/include/perf/evsel.h
index 699c0ed97d34..6f92204075c2 100644
--- a/tools/lib/perf/include/perf/evsel.h
+++ b/tools/lib/perf/include/perf/evsel.h
@@ -18,8 +18,10 @@ struct perf_counts_values {
uint64_t val;
uint64_t ena;
uint64_t run;
+ uint64_t id;
+ uint64_t lost;
};
- uint64_t values[3];
+ uint64_t values[5];
};
};