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Subject[PATCH 7/9] perf intel-pt: Tidy old_buffer handling in intel_pt_get_trace()
Date
intel_pt_get_trace() fixes overlaps between the current buffer and the
previous buffer ('old_buffer'). However the previous buffer might not have
had usable data (no PSB) so the comparison must be made against the
previous buffer that had usable data. Tidy that by keeping a pointer for
that purpose in struct intel_pt_queue.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
tools/perf/util/intel-pt.c | 24 +++++++++++-------------
1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
index cfb3614f5def..9a4f9cdb752f 100644
--- a/tools/perf/util/intel-pt.c
+++ b/tools/perf/util/intel-pt.c
@@ -132,6 +132,7 @@ struct intel_pt_queue {
struct intel_pt *pt;
unsigned int queue_nr;
struct auxtrace_buffer *buffer;
+ struct auxtrace_buffer *old_buffer;
void *decoder;
const struct intel_pt_state *state;
struct ip_callchain *chain;
@@ -226,7 +227,8 @@ static int intel_pt_do_fix_overlap(struct intel_pt *pt, struct auxtrace_buffer *
static int intel_pt_get_trace(struct intel_pt_buffer *b, void *data)
{
struct intel_pt_queue *ptq = data;
- struct auxtrace_buffer *buffer = ptq->buffer, *old_buffer = buffer;
+ struct auxtrace_buffer *buffer = ptq->buffer;
+ struct auxtrace_buffer *old_buffer = ptq->old_buffer;
struct auxtrace_queue *queue;

if (ptq->stop) {
@@ -235,7 +237,7 @@ static int intel_pt_get_trace(struct intel_pt_buffer *b, void *data)
}

queue = &ptq->pt->queues.queue_array[ptq->queue_nr];
-next:
+
buffer = auxtrace_buffer__next(queue, buffer);
if (!buffer) {
if (old_buffer)
@@ -267,16 +269,6 @@ static int intel_pt_get_trace(struct intel_pt_buffer *b, void *data)
}
b->ref_timestamp = buffer->reference;

- /*
- * If in snapshot mode and the buffer has no usable data, get next
- * buffer and again check overlap against old_buffer.
- */
- if (ptq->pt->snapshot_mode && !b->len)
- goto next;
-
- if (old_buffer)
- auxtrace_buffer__drop_data(old_buffer);
-
if (!old_buffer || ptq->pt->sampling_mode || (ptq->pt->snapshot_mode &&
!buffer->consecutive)) {
b->consecutive = false;
@@ -288,8 +280,14 @@ static int intel_pt_get_trace(struct intel_pt_buffer *b, void *data)
if (ptq->step_through_buffers)
ptq->stop = true;

- if (!b->len)
+ if (b->len) {
+ if (old_buffer)
+ auxtrace_buffer__drop_data(old_buffer);
+ ptq->old_buffer = buffer;
+ } else {
+ auxtrace_buffer__drop_data(buffer);
return intel_pt_get_trace(b, data);
+ }

return 0;
}
--
1.9.1
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