[PATCH v10 2/2] docs/perf: Add documentation for the Amlogic G12 DDR PMU

Bagas Sanjaya bagasdotme at gmail.com
Wed Nov 16 01:40:48 PST 2022 

On Wed, Nov 16, 2022 at 08:31:33AM +0800, Jiucheng Xu wrote:
> diff --git a/Documentation/admin-guide/perf/meson-ddr-pmu.rst b/Documentation/admin-guide/perf/meson-ddr-pmu.rst
> new file mode 100644
> index 000000000000..15e93a751ced
> --- /dev/null
> +++ b/Documentation/admin-guide/perf/meson-ddr-pmu.rst
> @@ -0,0 +1,70 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +===========================================================
> +Amlogic SoC DDR Bandwidth Performance Monitoring Unit (PMU)
> +===========================================================
> +
> +There is a bandwidth monitor inside the DRAM controller. The monitor includes
> +4 channels which can count the read/write request of accessing DRAM individually.
> +It can be helpful to show if the performance bottleneck is on DDR bandwidth.
> +
> +Currently, this driver supports the following 5 Perf events:
> +
> ++ meson_ddr_bw/total_rw_bytes/
> ++ meson_ddr_bw/chan_1_rw_bytes/
> ++ meson_ddr_bw/chan_2_rw_bytes/
> ++ meson_ddr_bw/chan_3_rw_bytes/
> ++ meson_ddr_bw/chan_4_rw_bytes/
> +
> +meson_ddr_bw/chan_{1,2,3,4}_rw_bytes/ events are the channel related events.
> +Each channel support using keywords as filter, which can let the channel
> +to monitor the individual IP module in SoC.
> +
> +The following keywords are the filter:
> +
> ++ arm             - DDR access request from CPU
> ++ vpu_read1       - DDR access request from OSD + VPP read
> ++ gpu             - DDR access request from 3D GPU
> ++ pcie            - DDR access request from PCIe controller
> ++ hdcp            - DDR access request from HDCP controller
> ++ hevc_front      - DDR access request from HEVC codec front end
> ++ usb3_0          - DDR access request from USB3.0 controller
> ++ hevc_back       - DDR access request from HEVC codec back end
> ++ h265enc         - DDR access request from HEVC encoder
> ++ vpu_read2       - DDR access request from DI read
> ++ vpu_write1      - DDR access request from VDIN write
> ++ vpu_write2      - DDR access request from di write
> ++ vdec            - DDR access request from legacy codec video decoder
> ++ hcodec          - DDR access request from H264 encoder
> ++ ge2d            - DDR access request from ge2d
> ++ spicc1          - DDR access request from SPI controller 1
> ++ usb0            - DDR access request from USB2.0 controller 0
> ++ dma             - DDR access request from system DMA controller 1
> ++ arb0            - DDR access request from arb0
> ++ sd_emmc_b       - DDR access request from SD eMMC b controller
> ++ usb1            - DDR access request from USB2.0 controller 1
> ++ audio           - DDR access request from Audio module
> ++ sd_emmc_c       - DDR access request from SD eMMC c controller
> ++ spicc2          - DDR access request from SPI controller 2
> ++ ethernet        - DDR access request from Ethernet controller
> +
> +
> +The following command is to show the total DDR bandwidth:
> +
> +  .. code-block:: bash
> +
> +      perf stat -a -e meson_ddr_bw/total_rw_bytes/ -I 1000 sleep 10
> +
> +This command will print the total DDR bandwidth per second.
> +
> +The following commands are to show how to use filter parameters:
> +
> +  .. code-block:: bash
> +
> +      perf stat -a -e meson_ddr_bw/chan_1_rw_bytes,arm=1/ -I 1000 sleep 10
> +      perf stat -a -e meson_ddr_bw/chan_2_rw_bytes,gpu=1/ -I 1000 sleep 10
> +      perf stat -a -e meson_ddr_bw/chan_3_rw_bytes,arm=1,gpu=1/ -I 1000 sleep 10
> +
> +The 1st command show how to use channel 1 to monitor the DDR bandwidth from ARM.
> +The 2nd command show using channel 2 to get the DDR bandwidth of GPU.
> +The 3rd command show using channel 3 to monitor the sum of ARM and GPU.

The wordings are rather weird, so I need to improve the doc:

---- >8 ----

diff --git a/Documentation/admin-guide/perf/meson-ddr-pmu.rst b/Documentation/admin-guide/perf/meson-ddr-pmu.rst
index 15e93a751ced8a..4a1fdb5aba4b24 100644
--- a/Documentation/admin-guide/perf/meson-ddr-pmu.rst
+++ b/Documentation/admin-guide/perf/meson-ddr-pmu.rst
@@ -4,11 +4,12 @@
 Amlogic SoC DDR Bandwidth Performance Monitoring Unit (PMU)
 ===========================================================
 
-There is a bandwidth monitor inside the DRAM controller. The monitor includes
-4 channels which can count the read/write request of accessing DRAM individually.
-It can be helpful to show if the performance bottleneck is on DDR bandwidth.
+The Amlogic Meson G12 SoC contains a bandwidth monitor inside DRAM controller.
+The monitor includes 4 channels which can count the read/write request of
+individual DRAM. It can be helpful to show if the performance bottleneck is on
+DDR bandwidth.
 
-Currently, this driver supports the following 5 Perf events:
+Currently, this driver supports the following 5 perf events:
 
 + meson_ddr_bw/total_rw_bytes/
 + meson_ddr_bw/chan_1_rw_bytes/
@@ -16,55 +17,54 @@ Currently, this driver supports the following 5 Perf events:
 + meson_ddr_bw/chan_3_rw_bytes/
 + meson_ddr_bw/chan_4_rw_bytes/
 
-meson_ddr_bw/chan_{1,2,3,4}_rw_bytes/ events are the channel related events.
-Each channel support using keywords as filter, which can let the channel
-to monitor the individual IP module in SoC.
+meson_ddr_bw/chan_{1,2,3,4}_rw_bytes/ events are channel-specific events.
+Each channel support filtering, which can let the channel to monitor
+individual IP module in SoC.
 
-The following keywords are the filter:
+Below are DDR access request event filter keywords:
 
-+ arm             - DDR access request from CPU
-+ vpu_read1       - DDR access request from OSD + VPP read
-+ gpu             - DDR access request from 3D GPU
-+ pcie            - DDR access request from PCIe controller
-+ hdcp            - DDR access request from HDCP controller
-+ hevc_front      - DDR access request from HEVC codec front end
-+ usb3_0          - DDR access request from USB3.0 controller
-+ hevc_back       - DDR access request from HEVC codec back end
-+ h265enc         - DDR access request from HEVC encoder
-+ vpu_read2       - DDR access request from DI read
-+ vpu_write1      - DDR access request from VDIN write
-+ vpu_write2      - DDR access request from di write
-+ vdec            - DDR access request from legacy codec video decoder
-+ hcodec          - DDR access request from H264 encoder
-+ ge2d            - DDR access request from ge2d
-+ spicc1          - DDR access request from SPI controller 1
-+ usb0            - DDR access request from USB2.0 controller 0
-+ dma             - DDR access request from system DMA controller 1
-+ arb0            - DDR access request from arb0
-+ sd_emmc_b       - DDR access request from SD eMMC b controller
-+ usb1            - DDR access request from USB2.0 controller 1
-+ audio           - DDR access request from Audio module
-+ sd_emmc_c       - DDR access request from SD eMMC c controller
-+ spicc2          - DDR access request from SPI controller 2
-+ ethernet        - DDR access request from Ethernet controller
++ arm             - from CPU
++ vpu_read1       - from OSD + VPP read
++ gpu             - from 3D GPU
++ pcie            - from PCIe controller
++ hdcp            - from HDCP controller
++ hevc_front      - from HEVC codec front end
++ usb3_0          - from USB3.0 controller
++ hevc_back       - from HEVC codec back end
++ h265enc         - from HEVC encoder
++ vpu_read2       - from DI read
++ vpu_write1      - from VDIN write
++ vpu_write2      - from di write
++ vdec            - from legacy codec video decoder
++ hcodec          - from H264 encoder
++ ge2d            - from ge2d
++ spicc1          - from SPI controller 1
++ usb0            - from USB2.0 controller 0
++ dma             - from system DMA controller 1
++ arb0            - from arb0
++ sd_emmc_b       - from SD eMMC b controller
++ usb1            - from USB2.0 controller 1
++ audio           - from Audio module
++ sd_emmc_c       - from SD eMMC c controller
++ spicc2          - from SPI controller 2
++ ethernet        - from Ethernet controller
 
 
-The following command is to show the total DDR bandwidth:
+Examples:
 
-  .. code-block:: bash
+  + Show the total DDR bandwidth per seconds:
 
-      perf stat -a -e meson_ddr_bw/total_rw_bytes/ -I 1000 sleep 10
+    .. code-block:: bash
 
-This command will print the total DDR bandwidth per second.
+       perf stat -a -e meson_ddr_bw/total_rw_bytes/ -I 1000 sleep 10
 
-The following commands are to show how to use filter parameters:
 
-  .. code-block:: bash
+  + Show individual DDR bandwidth from CPU and GPU respectively, as well as
+    sum of them:
 
-      perf stat -a -e meson_ddr_bw/chan_1_rw_bytes,arm=1/ -I 1000 sleep 10
-      perf stat -a -e meson_ddr_bw/chan_2_rw_bytes,gpu=1/ -I 1000 sleep 10
-      perf stat -a -e meson_ddr_bw/chan_3_rw_bytes,arm=1,gpu=1/ -I 1000 sleep 10
+    .. code-block:: bash
+
+       perf stat -a -e meson_ddr_bw/chan_1_rw_bytes,arm=1/ -I 1000 sleep 10
+       perf stat -a -e meson_ddr_bw/chan_2_rw_bytes,gpu=1/ -I 1000 sleep 10
+       perf stat -a -e meson_ddr_bw/chan_3_rw_bytes,arm=1,gpu=1/ -I 1000 sleep 10
 
-The 1st command show how to use channel 1 to monitor the DDR bandwidth from ARM.
-The 2nd command show using channel 2 to get the DDR bandwidth of GPU.
-The 3rd command show using channel 3 to monitor the sum of ARM and GPU.

Thanks.

-- 
An old man doll... just what I always wanted! - Clara
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