On Fri, Jun 11, 2021 at 01:31:41AM -0700, Denis Nikitin wrote:
Hi Suzuki,
On Thu, Jun 10, 2021 at 9:04 AM Suzuki K Poulose suzuki.poulose@arm.com wrote:
[...]
Are you able to confirm if the patch 3 alone fixes the above issue ? I am not convinced that Patch 1 is necessary.
Yes. "perf cs-etm: Remove callback cs_etm_find_snapshot()" alone fixes the issue.
Based on current testing result, we should give high priority for patches 2 and 3.
The patch 1 is controversial for how to handle the trace data kept in multiple AUX buffers; essentially it's up to how we understand the snapshot definition. I confirmed Intel-PT and CoreSight have the same behaviour for capturing trace data from multiple AUX ring buffers when snapshot occurs.
I'd like to leave patch 1/3 out, and resend it if we get conclusion. At the meantime, @Denis, if you have observed any profiling result (or profiling quality) difference caused by patch 1, the feedback would be very valuable.
Thanks a lot for Denis' testing and insight review from Suzuki!
Leo