perf auxtrace: Fix auxtrace queue conflict

[ Upstream commit b410ed2a8572d41c68bd9208555610e4b07d0703 ]

The only requirement of an auxtrace queue is that the buffers are in
time order.  That is achieved by making separate queues for separate
perf buffer or AUX area buffer mmaps.

That generally means a separate queue per cpu for per-cpu contexts, and
a separate queue per thread for per-task contexts.

When buffers are added to a queue, perf checks that the buffer cpu and
thread id (tid) match the queue cpu and thread id.

However, generally, that need not be true, and perf will queue buffers
correctly anyway, so the check is not needed.

In addition, the check gets erroneously hit when using sample mode to
trace multiple threads.

Consequently, fix that case by removing the check.

Fixes: e502789302a6 ("perf auxtrace: Add helpers for queuing AUX area tracing data")
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20210308151143.18338-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
index 4b898b15643dea20074c374815b7b165679f1896..80e461dd2db27e54cc69f8b707203947840c223b 100644 (file)
--- a/tools/perf/util/auxtrace.c
+++ b/tools/perf/util/auxtrace.c
@@ -239,10 +239,6 @@ static int auxtrace_queues__add_buffer(struct auxtrace_queues *queues,
                queue->set = true;
                queue->tid = buffer->tid;
                queue->cpu = buffer->cpu;
-       } else if (buffer->cpu != queue->cpu || buffer->tid != queue->tid) {
-               pr_err("auxtrace queue conflict: cpu %d, tid %d vs cpu %d, tid %d\n",
-                      queue->cpu, queue->tid, buffer->cpu, buffer->tid);
-               return -EINVAL;
        }
 
        buffer->buffer_nr = queues->next_buffer_nr++;