Bug#674153: [3.2.16 -> 3.2.17 regression] High reported CPU load when idle

["Doug Smythies" <dsmythies@telus.net>]

> On 2012.07.17 16:26 -0700 Jonathan Nieder wrote:
>
>Please test the attached patch against a 3.2.y kernel, for example following the instructions below:
>
> 0. prerequisites:
>
>	apt-get install git build-essential
>
> 1. get the kernel history, if you don't already have it:
>
>	git clone \
>	  git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>
> 2. fetch point releases:
>
>	cd linux
>	git remote add stable \
>	  git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
>	git fetch stable
>
> 3. configure, build, test:
>
>	git checkout stable/linux-3.2.y
>	cp /boot/config-$(uname -r) .config; # current configuration
>	scripts/config --disable DEBUG_INFO
>	make localmodconfig; # optional: minimize configuration
>	make deb-pkg; # optionally with -j<num> for parallel build
>	dpkg -i ../<name of package>; # as root
>	reboot
>	... test test test ...
>
>    Hopefully that will reproduce the bug.  So
>
> 4. try the patch:
>
>	cd linux
>	git am -3sc /path/to/the/patch
>	dpkg -i ../<name of package>; # as root
>	reboot
>	... test test test ...
>
> Hope that helps,
> Jonathan

Hi Jonathan,

Thanks for your instructions. I tried them, because
I have never successfully got and compiled the kernel
via GIT before.

Your instructions worked fine.

With only a superficial few hours on each kernel, I verified
The problem with kernel 3.2.23 and no problem with kernel
3.2.23 + patch.

Note: the majority of my testing (one or two hundred hours) were
Done with Ubuntu server edition 12.04, Kernel 3.2.0-24-generic
#39, and all three of:
556061b00c9f2fd6a5524b6bde823ef12f299ecf
5aaa0b7a2ed5b12692c9ffb5222182bd558d3146
5167e8d5417bf5c322a703d2927daec727ea40dd
manually backedited.

By the way this non-distro 3.2.23 kernel seems to run a lot faster
than the Ubuntu distro 3.2.0-24 kernel.

... Doug Smythies