Re: [PATCH v1 0/3] coresight: Fix for snapshot mode
From: Leo Yan <hidden>
Date: 2021-06-12 03:28:47
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linux-perf-users, lkml
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 [off-list ref] wrote:quoted
[...]quoted
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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel