configs: Enable HOTPLUG_CPU #6409
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This works and can be useful for debugging/benchmarking/low power use $ nproc 4 $ echo 0 | sudo tee /sys/devices/system/cpu/cpu3/online 0 $ echo 0 | sudo tee /sys/devices/system/cpu/cpu2/online 0 $ echo 0 | sudo tee /sys/devices/system/cpu/cpu1/online 0 $ nproc 1 Signed-off-by: Dom Cobley <[email protected]>
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Tested on Pi4 and while nothing bad happens, we are unable to offline a cpu (as you can on pi5). I think this is due to PSCI support in pi5 arm stub (using arm-trusted-firmware), which is not present in the more minimal stubs of Pi0-4. I suspect this is the code that checks: linux/arch/arm64/kernel/psci.c Line 50 in 0985b32 I've restricted the config changes to |
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timg236
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See: raspberrypi/linux#6412 kernel: dtoverlays: Fix up imx500 overlays to have unique clock nodes See: raspberrypi/linux#6415 kernel: configs: Enable HOTPLUG_CPU See: raspberrypi/linux#6409 kernel: dtoverlays: Add an overlay for Waveshare's 800x480 4.3" DSI screen See: raspberrypi/linux#6417 kernel: drm/vc4: Remove request for min clocks when hdmi output is disabled See: raspberrypi/linux#6416
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See: raspberrypi/linux#6412 kernel: dtoverlays: Fix up imx500 overlays to have unique clock nodes See: raspberrypi/linux#6415 kernel: configs: Enable HOTPLUG_CPU See: raspberrypi/linux#6409 kernel: dtoverlays: Add an overlay for Waveshare's 800x480 4.3" DSI screen See: raspberrypi/linux#6417 kernel: drm/vc4: Remove request for min clocks when hdmi output is disabled See: raspberrypi/linux#6416
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This works and can be useful for
debugging/benchmarking/low power use
$ nproc
4
$ echo 0 | sudo tee /sys/devices/system/cpu/cpu3/online
0
$ echo 0 | sudo tee /sys/devices/system/cpu/cpu2/online
0
$ echo 0 | sudo tee /sys/devices/system/cpu/cpu1/online
0
$ nproc
1