> > Looking at the perf ring buffer, there appears to be a missing barrier in > > perf_aux_output_end(): > > > > rb->user_page->aux_head = rb->aux_head; > > > > should be: > > > > smp_store_release(&rb->user_page->aux_head, rb->aux_head); > > > > It should also be using smp_load_acquire(). See > > Documentation/core-api/circular-buffers.rst > > > > And a (partial) patch has been proposed: https://lkml.org/lkml/2018/5/10/249 > > So, if that's all that needs to be fixed, can you use the same > buffer/code if that patch is merged? That's about one year old...: let me add the usual suspects in Cc: ;-) since I'm not sure what the plan was (or if I'm missing something) ... Speaking of ring buffer implementations (and relatively "old" patches), here's another quite interesting: https://lkml.kernel.org/r/20181211034032.32338-1-yuleixzhang@xxxxxxxxxxx Thanks, Andrea
