[PATCH v2 0/6] coresight: Add format attribute for setting the timestamp interval

Leo Yan leo.yan at arm.com
Tue Sep 30 08:20:20 PDT 2025


On Thu, Aug 14, 2025 at 11:49:51AM +0100, James Clark wrote:

[...]

> This is added as an event format attribute, rather than a Coresight
> config because it's something that the driver is already configuring
> automatically in Perf mode with any unused counter, so it's not possible
> to modify this with a config.

Tested on Juno-r2 for this series:

  # /mnt/build/perf record -e cs_etm/timestamp=1,ts_level=15/ -- ls
  # /mnt/build/perf script -D | grep I_TIMESTAMP | wc

   1305   11745   83337

  # /mnt/build/perf record -e cs_etm/timestamp=1,ts_level=0/ -- ls
  # /mnt/build/perf script -D | grep I_TIMESTAMP | wc

   120668 1086012 7705024

We can see a small counter (2 ^ 0 = 1) that records significant
timestamp packets.

Tested-by: Leo Yan <leo.yan at arm.com>



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