Many customers ask for support of Linux Kernel version 2.6 for their embedded projects. They are surprised when we tell them that we don't recommend to use Linux 2.6 for most embedded systems.
The document "Comparing Linux 2.4 and Linux 2.6 Kernels" explains the reasons. Here is a short Management Summary:
Using the 2.6 kernel on embedded systems implicates the following disadvantages:
- Slow to build: 2.6 takes 30...40% longer to compile
- Big memory footprint in flash: the 2.6 compressed kernel image is 30...40% bigger
- Big memory footprint in RAM: the 2.6 kernel needs 30...40% more RAM; the available RAM size for applications is 700kB smaller
- Slow to boot: 2.6 takes 5...15% longer to boot into multi-user mode
- Slow to run: context switches up to 96% slower, local communication latencies up to 80% slower, file system latencies up to 76% slower, local communication bandwidth less than 50% in some cases.