upgrade kernel

1.check current system's version

#uname -r

2.download the linux kernel source code package.

3.uncompress the kernel package to a directory

4.change to the directory

5.make mrproper

6.make menuconfig

 OR

cp /boot/config-? .config; sh -c 'yes ""| make oldconfig'

7.make

8.make modules

9.make modules_install

10.make install