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.
