[dpdk-dev] [PATCH 5/5] doc: add aarch64 generic counter section

[Jerin Jacob]

On Thu, May 7, 2020 at 3:29 AM Dharmik Thakkar <dharmik.thakkar at arm.com> wrote:
>
> Add a separate section for low-resolution generic counter
> for ARM64 profiling methods.
>
> Signed-off-by: Dharmik Thakkar <dharmik.thakkar at arm.com>
> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
> Reviewed-by: Phil Yang <phil.yang at arm.com>

Acked-by: Jerin Jacob <jerinj at marvell.com>



> ---
>  doc/guides/prog_guide/profile_app.rst | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/doc/guides/prog_guide/profile_app.rst b/doc/guides/prog_guide/profile_app.rst
> index a36ebef4db99..e5d0e9079e11 100644
> --- a/doc/guides/prog_guide/profile_app.rst
> +++ b/doc/guides/prog_guide/profile_app.rst
> @@ -57,11 +57,16 @@ For more derails refer to the
>  `ARM64 specific PMU events enumeration <http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.100095_0002_04_en/way1382543438508.html>`_.
>
>
> -High-resolution cycle counter
> -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +Low-resolution generic counter
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>  The default ``cntvct_el0`` based ``rte_rdtsc()`` provides a portable means to
> -get a wall clock counter in user space. Typically it runs at <= 100MHz.
> +get a wall clock counter in user space. Typically it runs at a lower clock frequency than the CPU clock frequency.
> +Cycles counted using this method should be scaled to CPU clock frequency.
> +
> +
> +High-resolution cycle counter
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>  The alternative method to enable ``rte_rdtsc()`` for a high resolution wall
>  clock counter is through the ARMv8 PMU subsystem. The PMU cycle counter runs
> --
> 2.20.1
>