问题
I need to run real time applications on Ubuntu RT Linux and was reading about ways to make linux act as RT system and I learned two ways to do it
- preemptive_rt kernel patching
- enabling
CONFIG_RT_GROUP_SCHEDflag in the kernel.
I've already tried my hands on 1st method Install RT Linux patch for Ubuntu
However, apart from uname -r showing #1 SMP PREEMPT RT I've no other proof that it is actually a RT system and hence want to try the 2nd method. Enable CONFIG_RT_GROUP_SCHED flag in the kernel and see its performance.
I read we can confirm if the kernel already has the flag by following command:
# zcat /proc/config.gz | grep RT_GROUP
CONFIG_RT_GROUP_SCHED=y
However, my system doesn't even have the config.gz file in proc, so I believe my kernel does not have this enabled. I'm relatively new to linux kernels so this might be naive but how can I enable this in the kernel?
回答1:
Step 1
Download linux kernel from https://www.kernel.org/pub/linux/kernel/. For the purpose of this PoC we downloaded linux-4.16.18.tar.gz kernel from above link.
Step 2 Unzip the kernel
$ tar -xzvf linux-4.16.18.tar.gz
Step 3
Move to kernel source directory
$ cd linux-4.16.18
Step 4
Install kernel build dependencies
$ sudo apt install git build-essential kernel-package fakeroot libncurses5-dev libssl-dev ccache bison flex
Step 5
Run kernel configuration
$make menuconfig
Step 6
Go to General setup ─> Control Group Support ─> CPU controller ─> Group scheduling for SCHED_RR/FIFO configuration as shown below:
Go to General setup ─> Kernel .config support and enable access to .config through /proc/config.gz
Step 7
Compile the kernel
$ make -j20
Make modules & install
$ sudo make modules_install -j20
$ sudo make install -j20
Step 8
Open the grub.cfg file to verify if kernel is installed
$ vim /boot/grub/grub.cfg
Look for the menuentry with menuentry 'Ubuntu, with Linux linux-4.16.18'
If it's not your default kernel then change the GRUB_DEFAULT=0 value to your kernel
Step 9
Reboot your system
sudo reboot
Step 10
Verify the system by the following command:
# zcat /proc/config.gz | grep RT_GROUP
CONFIG_RT_GROUP_SCHED=y
来源：https://stackoverflow.com/questions/56189710/how-to-enable-config-rt-group-sched-in-ubuntu-to-make-it-rt