Bootup linux kernel profiling tool including kexec?

Apart from OProfile, what tools do you recommend that I can use to profile my linux kernel while booting up?

I use kexec in Ubuntu server 9.04. OProfile doesn't seem to do the desired work for me, or at least I don't seem to be able to run it.

Any recomendation about a tool would be helpful, and if you know of a tool that can be used with kexec then that would be even better.

Many thanks

Other tools that can be used to profile the kernel include:

• Sysprof
• perf
• readprofile

Also see here for general information regarding profiling in Linux.

The boot process can be profiled using:

• Bootchart an example of this is available here This does everything after the kernel.
• Printk Times, this can be used to profile kernel bootup.
• Kernel Function Trace, this can be used to profile kernel bootup, though it has an approximate 30% overhead.
• Boot Probe, set of System Tap scripts for boot time profiling
• Also see Kernel Instrumentation