Re: [PATCH v1 1/3] coresight: etm-perf: Correct buffer syncing for snapshot

From: Leo Yan
Date: Tue Jun 08 2021 - 21:40:33 EST


On Wed, Jun 09, 2021 at 09:35:55AM +0800, Leo Yan wrote:

[...]

> > The problem with this approach is that if the AUX buffer is 4MB and the CS
> > buffer is 1MB then we only record 1MB, but because of N:1 topologies we may not
> > be able to do better. I haven't looked at the code yet, something I will do
> > tomorrow.
>
> Yes, the fixing in this patch copies the trace data is limited by the
> CoreSight bounce buffer length. So if CoreSight buffer length is
> 1MiB, then we have no chance to allocate 4MiB for AUX buffer.

Sorry for typo, just correct:

if CoreSight buffer length is 1MiB, then we have no chance to *copy*
4MiB trace data for AUX buffer.