mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-12 13:55:32 +00:00
Code Issues Releases Wiki Activity

perf auxtrace: Fix auxtrace queue conflict

Browse source 
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: e502789302 ("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>
This commit is contained in:
Adrian Hunter 2021-03-08 17:11:43 +02:00 committed by Arnaldo Carvalho de Melo
parent 05a59d7979
commit b410ed2a85
1 changed files with 0 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
tools/perf/util/auxtrace.c
View file

@ -298,10 +298,6 @@ static int auxtrace_queues__queue_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++;