Intel PT driver needs to be able to communicate partial AUX transactions, that is, transactions with gaps in data for reasons other than no room left in the buffer (i.e. truncated transactions). Therefore, this condition does not imply a wakeup for the consumer.
To this end, add a new "partial" AUX flag. Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Mathieu Poirier <[email protected]> Signed-off-by: Alexander Shishkin <[email protected]> --- include/uapi/linux/perf_event.h | 1 + kernel/events/ring_buffer.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index c66a485a24..8306415207 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -885,6 +885,7 @@ enum perf_callchain_context { */ #define PERF_AUX_FLAG_TRUNCATED 0x01 /* record was truncated to fit */ #define PERF_AUX_FLAG_OVERWRITE 0x02 /* snapshot from overwrite mode */ +#define PERF_AUX_FLAG_PARTIAL 0x04 /* record contains gaps */ #define PERF_FLAG_FD_NO_GROUP (1UL << 0) #define PERF_FLAG_FD_OUTPUT (1UL << 1) diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index f3ebafe060..cd5e902a27 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -425,8 +425,8 @@ EXPORT_SYMBOL_GPL(perf_aux_output_begin); */ void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size) { + bool wakeup = !!(handle->aux_flags & PERF_AUX_FLAG_TRUNCATED); struct ring_buffer *rb = handle->rb; - bool wakeup = !!handle->aux_flags; unsigned long aux_head; /* in overwrite mode, driver provides aux_head via handle */ -- 2.11.0
