Hi Mathieu, Suzuki,
On Mon, Aug 09, 2021 at 07:14:00PM +0800, Leo Yan wrote:
Since a memory barrier is required between AUX trace data store and aux_head store, and the AUX trace data is filled with memcpy(), it's sufficient to use smp_wmb() so can ensure the trace data is visible prior to updating aux_head.
Signed-off-by: Leo Yan leo.yan@linaro.org Reviewed-by: Suzuki K Poulose suzuki.poulose@arm.com
Could you pick up patches 02 and 03 in this series? Please note, patch 02 has the review tag from Suzuki, but I didn't receive the review tag for patch 03.
If anything need to follow up, just let me know. Thanks!
drivers/hwtracing/coresight/coresight-tmc-etr.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index acdb59e0e661..13fd1fc730ed 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1563,6 +1563,14 @@ tmc_update_etr_buffer(struct coresight_device *csdev, */ if (etr_perf->snapshot) handle->head += size;
- /*
* Ensure that the AUX trace data is visible before the aux_head* is updated via perf_aux_output_end(), as expected by the* perf ring buffer.*/- smp_wmb();
out: /* * Don't set the TRUNCATED flag in snapshot mode because 1) the -- 2.25.1