131 lines
5 KiB
Diff
131 lines
5 KiB
Diff
|
From 26e96232c314f9d34f6ee3be365c04918967084e Mon Sep 17 00:00:00 2001
|
||
|
|
From: Hans de Goede <hdegoede@redhat.com>
|
||
|
|
Date: Mon, 22 Jan 2024 17:18:00 +0100
|
||
|
|
Subject: [PATCH 23/25] libcamera: Add "Software ISP benchmarking"
|
||
|
|
documentation
|
||
|
|
|
||
|
|
Add a "Software ISP benchmarking" documentation section which describes
|
||
|
|
the performance/power consumption measurements used during
|
||
|
|
the Software ISP's development.
|
||
|
|
|
||
|
|
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
|
||
|
|
---
|
||
|
|
Documentation/index.rst | 1 +
|
||
|
|
Documentation/meson.build | 1 +
|
||
|
|
Documentation/software-isp-benchmarking.rst | 82 +++++++++++++++++++++
|
||
|
|
3 files changed, 84 insertions(+)
|
||
|
|
create mode 100644 Documentation/software-isp-benchmarking.rst
|
||
|
|
|
||
|
|
diff --git a/Documentation/index.rst b/Documentation/index.rst
|
||
|
|
index 63fac72d..5442ae75 100644
|
||
|
|
--- a/Documentation/index.rst
|
||
|
|
+++ b/Documentation/index.rst
|
||
|
|
@@ -24,3 +24,4 @@
|
||
|
|
Lens driver requirements <lens_driver_requirements>
|
||
|
|
Python Bindings <python-bindings>
|
||
|
|
Camera Sensor Model <camera-sensor-model>
|
||
|
|
+ SoftwareISP Benchmarking <software-isp-benchmarking>
|
||
|
|
diff --git a/Documentation/meson.build b/Documentation/meson.build
|
||
|
|
index 7a58fec8..3872e0a8 100644
|
||
|
|
--- a/Documentation/meson.build
|
||
|
|
+++ b/Documentation/meson.build
|
||
|
|
@@ -80,6 +80,7 @@ if sphinx.found()
|
||
|
|
'lens_driver_requirements.rst',
|
||
|
|
'python-bindings.rst',
|
||
|
|
'sensor_driver_requirements.rst',
|
||
|
|
+ 'software-isp-benchmarking.rst',
|
||
|
|
'../README.rst',
|
||
|
|
]
|
||
|
|
|
||
|
|
diff --git a/Documentation/software-isp-benchmarking.rst b/Documentation/software-isp-benchmarking.rst
|
||
|
|
new file mode 100644
|
||
|
|
index 00000000..738c8c65
|
||
|
|
--- /dev/null
|
||
|
|
+++ b/Documentation/software-isp-benchmarking.rst
|
||
|
|
@@ -0,0 +1,82 @@
|
||
|
|
+.. SPDX-License-Identifier: CC-BY-SA-4.0
|
||
|
|
+
|
||
|
|
+.. _software-isp-benchmarking:
|
||
|
|
+
|
||
|
|
+Software ISP benchmarking
|
||
|
|
+=========================
|
||
|
|
+
|
||
|
|
+The Software ISP is paricular sensitive to performance regressions
|
||
|
|
+therefor it is a good idea to always benchmark the Software ISP
|
||
|
|
+before and after making changes to it and ensure that there are
|
||
|
|
+no performance regressions.
|
||
|
|
+
|
||
|
|
+DebayerCpu class builtin benchmark
|
||
|
|
+----------------------------------
|
||
|
|
+
|
||
|
|
+The DebayerCpu class has a builtin benchmark. This benchmark
|
||
|
|
+measures the time spend on processing (collecting statistics
|
||
|
|
+and debayering) only, it does not measure the time spend on
|
||
|
|
+capturing or outputting the frames.
|
||
|
|
+
|
||
|
|
+The builtin benchmark always runs. So this can be used by simply
|
||
|
|
+running "cam" or "qcam" with a pipeline using the Software ISP.
|
||
|
|
+
|
||
|
|
+When it runs it will skip measuring the first 30 frames to
|
||
|
|
+allow the caches and the CPU temperature (turbo-ing) to warm-up
|
||
|
|
+and then it measures 30 fps and shows the total and per frame
|
||
|
|
+processing time using an info level log message:
|
||
|
|
+
|
||
|
|
+.. code-block::
|
||
|
|
+
|
||
|
|
+ INFO Debayer debayer_cpu.cpp:907 Processed 30 frames in 244317us, 8143 us/frame
|
||
|
|
+
|
||
|
|
+To get stable measurements it is advised to disable any other processes which
|
||
|
|
+may cause significant CPU usage (e.g. disable wifi, bluetooth and browsers).
|
||
|
|
+When possible it is also advisable to disable CPU turbo-ing and
|
||
|
|
+frequency-scaling.
|
||
|
|
+
|
||
|
|
+For example when benchmarking on a Lenovo ThinkPad X1 Yoga Gen 8, with
|
||
|
|
+the charger plugged in, the CPU can be fixed to run at 2 GHz using:
|
||
|
|
+
|
||
|
|
+.. code-block::
|
||
|
|
+
|
||
|
|
+ sudo x86_energy_perf_policy --turbo-enable 0
|
||
|
|
+ sudo cpupower frequency-set -d 2GHz -u 2GHz
|
||
|
|
+
|
||
|
|
+with these settings the builtin bench reports a processing time of ~7.8ms/frame
|
||
|
|
+on this laptop for FHD SGRBG10 (unpacked) bayer data.
|
||
|
|
+
|
||
|
|
+Measuring power consumption
|
||
|
|
+---------------------------
|
||
|
|
+
|
||
|
|
+Since the Software ISP is often used on mobile devices it is also
|
||
|
|
+important to measure power consumption and ensure that that does
|
||
|
|
+not regress.
|
||
|
|
+
|
||
|
|
+For example to measure power consumption on a Lenovo ThinkPad X1 Yoga Gen 8
|
||
|
|
+it needs to be running on battery and it should be configured with its
|
||
|
|
+platform-profile (/sys/firmware/acpi/platform_profile) set to balanced and
|
||
|
|
+with its default turbo and frequency-scaling behavior to match real world usage.
|
||
|
|
+
|
||
|
|
+Then start qcam to capture a FHD picture at 30 fps and position the qcam window
|
||
|
|
+so that it is fully visible. After this run the following command to monitor
|
||
|
|
+the power consumption:
|
||
|
|
+
|
||
|
|
+.. code-block::
|
||
|
|
+
|
||
|
|
+ watch -n 10 cat /sys/class/power_supply/BAT0/power_now /sys/class/hwmon/hwmon6/fan?_input
|
||
|
|
+
|
||
|
|
+Note this not only measures the power consumption in ųW it also monitors
|
||
|
|
+the speed of this laptop's 2 fans. This is important because depending on
|
||
|
|
+the ambient temperature the 2 fans may spin up while testing and this
|
||
|
|
+will cause an additional power consumption of approx. 0.5W messing up
|
||
|
|
+the measurement.
|
||
|
|
+
|
||
|
|
+After starting qcam + the watch command let the laptop sit without using
|
||
|
|
+it for 2 minutes for the readings to stabilize. Then check that the fans
|
||
|
|
+have not turned on and manually take a couple of consecutive power readings
|
||
|
|
+and avarage these.
|
||
|
|
+
|
||
|
|
+On the example Lenovo ThinkPad X1 Yoga Gen 8 laptop this results in
|
||
|
|
+a measured power consumption of approx. 13W while running qcam versus
|
||
|
|
+approx. 4-5W while setting idle with its OLED panel on.
|
||
|
|
--
|
||
|
|
2.43.0
|
||
|
|
|