Reviewed-by: Mike Leach <mike.leach@xxxxxxxxxx>
On Thu, 13 Jan 2022 at 09:11, James Clark <james.clark@xxxxxxx> wrote:
>
> This is to allow them to be referenced in a later commit. There was
> also a mistake where sysFS was introduced as section 2, but numbered
> as section 1. And vice versa for 'Using perf framework'. This can't
> happen with unnumbered sections.
>
> Signed-off-by: James Clark <james.clark@xxxxxxx>
> ---
> Documentation/trace/coresight/coresight.rst | 17 ++++++++++++-----
> 1 file changed, 12 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/trace/coresight/coresight.rst b/Documentation/trace/coresight/coresight.rst
> index a15571d96cc8..db66ff45ff4c 100644
> --- a/Documentation/trace/coresight/coresight.rst
> +++ b/Documentation/trace/coresight/coresight.rst
> @@ -339,7 +339,8 @@ Preference is given to the former as using the sysFS interface
> requires a deep understanding of the Coresight HW. The following sections
> provide details on using both methods.
>
> -1) Using the sysFS interface:
> +Using the sysFS interface
> +~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Before trace collection can start, a coresight sink needs to be identified.
> There is no limit on the amount of sinks (nor sources) that can be enabled at
> @@ -446,7 +447,8 @@ wealth of possibilities that coresight provides.
> Instruction 0 0x8026B588 E8BD8000 true LDM sp!,{pc}
> Timestamp Timestamp: 17107041535
>
> -2) Using perf framework:
> +Using perf framework
> +~~~~~~~~~~~~~~~~~~~~
>
> Coresight tracers are represented using the Perf framework's Performance
> Monitoring Unit (PMU) abstraction. As such the perf framework takes charge of
> @@ -495,7 +497,11 @@ More information on the above and other example on how to use Coresight with
> the perf tools can be found in the "HOWTO.md" file of the openCSD gitHub
> repository [#third]_.
>
> -2.1) AutoFDO analysis using the perf tools:
> +Advanced perf framework usage
> +-----------------------------
> +
> +AutoFDO analysis using the perf tools
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> perf can be used to record and analyze trace of programs.
>
> @@ -513,7 +519,8 @@ The --itrace option controls the type and frequency of synthesized events
> Note that only 64-bit programs are currently supported - further work is
> required to support instruction decode of 32-bit Arm programs.
>
> -2.2) Tracing PID
> +Tracing PID
> +~~~~~~~~~~~
>
> The kernel can be built to write the PID value into the PE ContextID registers.
> For a kernel running at EL1, the PID is stored in CONTEXTIDR_EL1. A PE may
> @@ -547,7 +554,7 @@ wants to trace PIDs for both host and guest, the two configs "contextid1" and
>
>
> Generating coverage files for Feedback Directed Optimization: AutoFDO
> ----------------------------------------------------------------------
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> 'perf inject' accepts the --itrace option in which case tracing data is
> removed and replaced with the synthesized events. e.g.
> --
> 2.28.0
>
--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK
