Compiling a single Linux Kernel module inside the Kernel tree

I recently find out a faster way to compile a single module in the Linux Kernel tree thanks to this post:

	$ time make modules SUBDIRS=drivers/media/platform/vivid
	Building modules, stage 2.
	MODPOST 1 modules
	CC drivers/media/platform/vivid/vivid.mod.o
	LD [M] drivers/media/platform/vivid/vivid.ko
	real 0m2.279s
	user 0m0.847s
	sys 0m0.924s

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What I was doing before was taking much more time:

	$ time make drivers/media/platform/vivid/vivid.ko
	CHK include/config/kernel.release
	CHK include/generated/uapi/linux/version.h
	CHK include/generated/utsrelease.h
	CHK include/generated/bounds.h
	CHK include/generated/asm-offsets.h
	CALL scripts/checksyscalls.sh
	MODPOST 4059 modules
	CC drivers/media/platform/vivid/vivid.mod.o
	LD [M] drivers/media/platform/vivid/vivid.ko
	real 2m26.061s
	user 0m13.959s
	sys 0m29.722s

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Or a pure make -j5, even if I had already compiled my Kernel once and just modified one module, was taking me ~5 minutes. So each tiny test I made (like changing a the contents of a string) was taking me that long, now it takes some seconds using the make modules SUBDIRS=path/to/module command \o/

To update the module I just copy the .ko to the right place:

sudo cp /path/to/my/module/module.ko /lib/modules/`uname -r`/kernel/path/to/my/module/module.ko

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It usually works if you made a simple change in the code. Or you can use the SUBDIRS too:

sudo make modules_install SUBDIRS=drivers/media/platform/vivid

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