1 .. SPDX-License-Identifier: GPL-2.0
2
3 ===========================================================
4 Amlogic SoC DDR Bandwidth Performance Monitoring Unit (PMU)
5 ===========================================================
6
7 The Amlogic Meson G12 SoC contains a bandwidth monitor inside DRAM controller.
8 The monitor includes 4 channels. Each channel can count the request accessing
9 DRAM. The channel can count up to 3 AXI port simultaneously. It can be helpful
10 to show if the performance bottleneck is on DDR bandwidth.
11
12 Currently, this driver supports the following 5 perf events:
13
14 + meson_ddr_bw/total_rw_bytes/
15 + meson_ddr_bw/chan_1_rw_bytes/
16 + meson_ddr_bw/chan_2_rw_bytes/
17 + meson_ddr_bw/chan_3_rw_bytes/
18 + meson_ddr_bw/chan_4_rw_bytes/
19
20 meson_ddr_bw/chan_{1,2,3,4}_rw_bytes/ events are channel-specific events.
21 Each channel support filtering, which can let the channel to monitor
22 individual IP module in SoC.
23
24 Below are DDR access request event filter keywords:
25
26 + arm - from CPU
27 + vpu_read1 - from OSD + VPP read
28 + gpu - from 3D GPU
29 + pcie - from PCIe controller
30 + hdcp - from HDCP controller
31 + hevc_front - from HEVC codec front end
32 + usb3_0 - from USB3.0 controller
33 + hevc_back - from HEVC codec back end
34 + h265enc - from HEVC encoder
35 + vpu_read2 - from DI read
36 + vpu_write1 - from VDIN write
37 + vpu_write2 - from di write
38 + vdec - from legacy codec video decoder
39 + hcodec - from H264 encoder
40 + ge2d - from ge2d
41 + spicc1 - from SPI controller 1
42 + usb0 - from USB2.0 controller 0
43 + dma - from system DMA controller 1
44 + arb0 - from arb0
45 + sd_emmc_b - from SD eMMC b controller
46 + usb1 - from USB2.0 controller 1
47 + audio - from Audio module
48 + sd_emmc_c - from SD eMMC c controller
49 + spicc2 - from SPI controller 2
50 + ethernet - from Ethernet controller
51
52
53 Examples:
54
55 + Show the total DDR bandwidth per seconds:
56
57 .. code-block:: bash
58
59 perf stat -a -e meson_ddr_bw/total_rw_bytes/ -I 1000 sleep 10
60
61
62 + Show individual DDR bandwidth from CPU and GPU respectively, as well as
63 sum of them:
64
65 .. code-block:: bash
66
67 perf stat -a -e meson_ddr_bw/chan_1_rw_bytes,arm=1/ -I 1000 sleep 10
68 perf stat -a -e meson_ddr_bw/chan_2_rw_bytes,gpu=1/ -I 1000 sleep 10
69 perf stat -a -e meson_ddr_bw/chan_3_rw_bytes,arm=1,gpu=1/ -I 1000 sleep 10
70
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.