mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 10:40:15 +02:00
537216e59f
Add a user guide to show how to use DDR PMU to monitor DDR bandwidth on Amlogic G12 SoC Signed-off-by: Jiucheng Xu <jiucheng.xu@amlogic.com> Reviewed-by: Chris Healy <healych@amazon.com> Link: https://lore.kernel.org/r/20221121021602.3306998-2-jiucheng.xu@amlogic.com Signed-off-by: Will Deacon <will@kernel.org>
70 lines
2.4 KiB
ReStructuredText
70 lines
2.4 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0
|
|
|
|
===========================================================
|
|
Amlogic SoC DDR Bandwidth Performance Monitoring Unit (PMU)
|
|
===========================================================
|
|
|
|
The Amlogic Meson G12 SoC contains a bandwidth monitor inside DRAM controller.
|
|
The monitor includes 4 channels. Each channel can count the request accessing
|
|
DRAM. The channel can count up to 3 AXI port simultaneously. 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 channel-specific events.
|
|
Each channel support filtering, which can let the channel to monitor
|
|
individual IP module in SoC.
|
|
|
|
Below are DDR access request event filter keywords:
|
|
|
|
+ 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
|
|
|
|
|
|
Examples:
|
|
|
|
+ Show the total DDR bandwidth per seconds:
|
|
|
|
.. code-block:: bash
|
|
|
|
perf stat -a -e meson_ddr_bw/total_rw_bytes/ -I 1000 sleep 10
|
|
|
|
|
|
+ Show individual DDR bandwidth from CPU and GPU respectively, as well as
|
|
sum of them:
|
|
|
|
.. 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
|
|
|