Notes for Linux-2.6.21.3 compilation process

Linux-2.6.21.3 compilation process notes-Linux general technology-Linux programming and kernel information, below is the details to read. MACHINE: dell 1950
System: RedHat RHEL5 (2.6.18-8. el5)

1. Download linux-2.6.21.3.tar.bz2 from www.kernel.org.

# Wget http://www.kernel.org/pub/linux/... ux-2.6.21.3.tar.bz2

2. decompress the package to/usr/src.

# Tar jxvf linux-2.6.21.3.tar.bz2-C/usr/src/linux-2.6.21.3; cd/usr/src/

3. Create a soft linux-2.6.21.3 for linux

# Ln-s/usr/src/linux-2.6.21.3/usr/src/linux; cd/usr/src/linux

4. Optimize and modify the kernel source code

1). Modify/usr/src/linux/include/linux/posix_types.h
Set the maximum number supported by fd_set
# Define _ FD_SETSIZE 1024 ---> 65536

2) Modify/usr/src/linux/include/linux/fs. h
Set the maximum number of opened files (number of TCP connections)
# Define INR_OPEN 1024 ---> 65536
# Define NR_FILE 8192 ---> 65536
# Define NR_RESERVED_FILES 10 ---> 128

3) Modify/usr/src/linux/include/net/tcp. h.
Set the TIMEOUT time to 1 second.
# Define TCP_TIMEWAIT_LEN (60 * HZ) 60 ---> 1 * HZ
Set the number of semi-join retries in the backlog queue. Each time, the corresponding time is spent, which is essentially to reduce the retry time.
# Define TCP_SYNACK_RETRIES 5 ---> 3


5. Copy the. config file from the/usr/src/kernels/2.6.18-8. el5-i686/directory of the original RHEL5 to/usr/src/linux

# Cp/usr/src/kernel/2.6.18-8. e15-i686/. config/usr/src/linux

6. Switch to/usr/src/linux to start compiling the new kernel.

# Cd/usr/src/linux; make menuconfig

Save and exit without any changes.

Note: ext4 file system is added to the kernel after 2.6.19. You can select ext4 file system module in file systems.


7. Compile and install
Step: make-jn (n indicates the process of simultaneous compilation, which can speed up compilation. n is determined by your configuration, and my configuration is 15-25)
Make modules_install install


Note: You can use make modules_install install to install the new kernel during the first compilation and installation. to update or upgrade the kernel, you only need to use make modules_install, and use make install to run panic when loading the new kernel!


8. Modify/etc/grub. conf
# Grub. conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a/boot partition. This means that
# All kernel and initrd paths are relative to/boot/, eg.
# Root (hd0, 0)
# Kernel/vmlinuz-version ro root =/dev/sda3
# Initrd-version.img/initrd
# Boot =/dev/sda
Default = 0
Timeout = 5
Splashimage = (hd0, 0)/grub/splash.xpm.gz
Hiddenmenu
Title Red Hat Enterprise Linux Server (2.6.21.3)
Root (hd0, 0)
Kernel/vmlinuz-2.6.21.3 ro root = LABEL =/
Initrd/initrd-2.6.21.3.img
Title Red Hat Enterprise Linux Server (2.6.18-8. el5)
Root (hd0, 0)
Kernel/vmlinuz-2.6.18-8.el5 ro root = LABEL =/
Initrd/initrd-2.6.18-8.el5.img

9. reboot

10. After startup
# Uname-r
2.6.21.3

The kernel is compiled and installed successfully.