On Wed, Jun 25, 2014 at 02:24:51PM +0300, Alexander Shishkin wrote: > Peter Zijlstra <[email protected]> writes: > > > On Wed, Jun 11, 2014 at 06:41:49PM +0300, Alexander Shishkin wrote: > >> +void perf_aux_output_end(struct perf_output_handle *handle, unsigned long > >> size, > >> + bool truncated) > >> +{ > >> + struct ring_buffer *rb = handle->rb; > >> + unsigned long aux_head; > >> + > >> + aux_head = local_read(&rb->aux_head); > >> + local_add(size, &rb->aux_head); > >> + > >> + rb->user_page->aux_head = local_read(&rb->aux_head); > >> + smp_wmb(); > >> + > >> + perf_output_wakeup(handle); > >> + handle->event = NULL; > >> + > >> + ring_buffer_put(rb); > >> +} > > > > This thing is distinctly less complex than perf_output_put_handle().. ? > > This one doesn't support nested writers, but there shouldn't be any > either. But I notice now that the barrier is misplaced. Wakeup watermark > is not yet taken care of, but will be. Anything else I'm missing?
Maybe put a comment in about explicitly not supporting nesting etc. Maybe also a debug check to make sure we catch anybody doing it anyway. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
