diff mbox series

[5/5] doc: add aarch64 generic counter section

Message ID 20200506215847.7628-5-dharmik.thakkar@arm.com (mailing list archive)
State Superseded, archived
Headers
Series [1/5] app/testpmd: print clock with CPU cycles per pkt |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/travis-robot warning Travis build: failed
ci/Intel-compilation fail Compilation issues

Commit Message

Dharmik Thakkar May 6, 2020, 9:58 p.m. UTC 
  Add a separate section for low-resolution generic counter
for ARM64 profiling methods.

Signed-off-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Phil Yang <phil.yang@arm.com>
---
 doc/guides/prog_guide/profile_app.rst | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

Comments

Jerin Jacob May 7, 2020, 5:17 a.m. UTC | #1 
On Thu, May 7, 2020 at 3:29 AM Dharmik Thakkar <dharmik.thakkar@arm.com> wrote:
>
> Add a separate section for low-resolution generic counter
> for ARM64 profiling methods.
>
> Signed-off-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> Reviewed-by: Phil Yang <phil.yang@arm.com>

Acked-by: Jerin Jacob <jerinj@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
>
diff mbox series

Patch

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