Hello,

Can I get a step by step example of how to modify CGroup default configurations and then make a new kernel image from the kernel source codes?

Regards,

Heng

There are innumerable guides on how to set kernel config options and compile the kernel.
Likely will depend on your distro.

I would be very surprised if you need to for cgroups, but the question is so poorly framed, it is almost impossible to answer.

1 members found this post helpful.

Thanks for the quick response. This is my first time to explore the Linux kernel source codes as a linux application developer due to my current application software development project's special needs.
I needed to install a third party's software which requires all the CGroups are enabled by defaults in the kernel side so that their application can function correctly. Unfortunately, my system came with all the CGroups disabled by default and all the info directed me to modify kernel configurations and reinstall it again. Luckily, my hardware vendor share the kernel source codes to me but provided no additional helps in this regard which just like you said it depends on our special needs.
In any case, I accidentally resolved my question as below. Let me know if you have any further suggestions.

Step 1: Run the following command which is instructed in the README file of kernel source codes folder.

make O=/home/name/build/kernel menuconfig

Step 2: Wait for "Linux Kernel Configuration Menu" displayed.

Step 3: Select and enter the "General Setup" sub-menu.

Step 4: Select and mark all options in the "Control Group Support"

Step 5: Save and Exit

Step 6: Run the following command to recompile the kernel source codes.

make O=/home/name/build/kernel

Regards,

Heng

Depending on the distro, that might work. Which distro are you using?

My linux distro is Ubuntu 16.04 and kernel 3.10.
By the way, I also required to upgrade the kernel to version 4.4 or greater. Any suggestions?

Regards,

Heng

Looks like this should do the job, and be supported as well. Might even have the cgroups options selected as well if you are lucky.
I don't use Ubuntu, but just checked a Linux Mint desktop system, and all the cgroup options were enabled except 2 debug options. I am very surprised Ubuntu doesn't have them.

Thanks for the info. I will try it as soon as possible and report back my results.

Regards,

Heng

If you're using Ubuntu, then you probably want to build the kernel the Debian way. Did you check /boot/config-version to see if cgroups are selected? Mine looks like this

My /boot folder has no files in there at all. Is that normal?

Regards,

Heng

Finally successfully recompiled kernel source codes and get some new configuration files created and copied to the /boot folder which includes the following info.
Next step is to reboot the system?

CONFIG_CGROUPS=y
CONFIG_PAGE_COUNTER=y
CONFIG_MEMCG=y
CONFIG_MEMCG_SWAP=y
CONFIG_MEMCG_SWAP_ENABLED=y
CONFIG_BLK_CGROUP=y
CONFIG_DEBUG_BLK_CGROUP=y
CONFIG_CGROUP_WRITEBACK=y
CONFIG_CGROUP_SCHED=y
CONFIG_FAIR_GROUP_SCHED=y
# CONFIG_CFS_BANDWIDTH is not set
# CONFIG_RT_GROUP_SCHED is not set
CONFIG_CGROUP_PIDS=y
CONFIG_CGROUP_RDMA=y
CONFIG_CGROUP_FREEZER=y
CONFIG_CGROUP_DEVICE=y
CONFIG_CGROUP_CPUACCT=y

That's interesting there was nothing in /boot before you installed the new kernel.

I have just learned how to configure and recompile a given kernel source code in Ubuntu. Now, the real problem is to figure out how to boot up this special system with a new given kernel image? To my knowledge, each embedded linux system may have its own customized bootloader and kernel image. Any suggestion on how to tackle these issues next? Again, I am only a newbie of linux application developer.

Regards,

Heng

if you did it according to the kernel README, you must generate an initramfs imageThen it should boot. Unless you haven't made and installed the modules yet, in which case you'll need to do But if you did it the Debian way, you only have to install the resulting package files and reboot.

The module was disabled. However, after module is enabled but getting the following kernel compilation error messages.


CALL /home/ubuntu/Kernel/src4/scripts/checksyscalls.sh
CHK scripts/mod/devicetable-offsets.h
HOSTCC scripts/sign-file
/usr/bin/ld: cannot find -lcrypto
collect2: error: ld returned 1 exit status
scripts/Makefile.host:90: recipe for target 'scripts/sign-file' failed
make[2]: *** [scripts/sign-file] Error 1
/home/ubuntu/Kernel/src4/Makefile:557: recipe for target 'scripts' failed
make[1]: *** [scripts] Error 2
make[1]: Leaving directory '/home/ubuntu/src4/kernel'
Makefile:146: recipe for target 'sub-make' failed
make: *** [sub-make] Error 2
ubuntu@localhost:~/Kernel/src4$

Try building the kernel the Debian way, since Ubuntu is a Debian distro. All you have to do is configure the kernel and run from thye sources directoryBut you must use the kernel-source package from the Ubuntu repos.