perf evlist: Steal mmap reading routine from 'perf top'
Will be used in the upcoming 'perf test' entry for the evlist mmap
routines.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index df85c1f..58352ad 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1100,67 +1100,17 @@
static void perf_session__mmap_read_cpu(struct perf_session *self, int cpu)
{
- struct perf_mmap *md = &evsel_list->mmap[cpu];
- unsigned int head = perf_mmap__read_head(md);
- unsigned int old = md->prev;
- unsigned char *data = md->base + page_size;
struct sample_data sample;
- int diff;
+ event_t *event;
- /*
- * If we're further behind than half the buffer, there's a chance
- * the writer will bite our tail and mess up the samples under us.
- *
- * If we somehow ended up ahead of the head, we got messed up.
- *
- * In either case, truncate and restart at head.
- */
- diff = head - old;
- if (diff > md->mask / 2 || diff < 0) {
- fprintf(stderr, "WARNING: failed to keep up with mmap data.\n");
-
- /*
- * head points to a known good entry, start there.
- */
- old = head;
- }
-
- for (; old != head;) {
- event_t *event = (event_t *)&data[old & md->mask];
-
- event_t event_copy;
-
- size_t size = event->header.size;
-
- /*
- * Event straddles the mmap boundary -- header should always
- * be inside due to u64 alignment of output.
- */
- if ((old & md->mask) + size != ((old + size) & md->mask)) {
- unsigned int offset = old;
- unsigned int len = min(sizeof(*event), size), cpy;
- void *dst = &event_copy;
-
- do {
- cpy = min(md->mask + 1 - (offset & md->mask), len);
- memcpy(dst, &data[offset & md->mask], cpy);
- offset += cpy;
- dst += cpy;
- len -= cpy;
- } while (len);
-
- event = &event_copy;
- }
-
+ while ((event = perf_evlist__read_on_cpu(evsel_list, cpu)) != NULL) {
event__parse_sample(event, self, &sample);
+
if (event->header.type == PERF_RECORD_SAMPLE)
event__process_sample(event, &sample, self);
else
event__process(event, &sample, self);
- old += size;
}
-
- md->prev = old;
}
static void perf_session__mmap_read(struct perf_session *self)