Steps to port oprofile to new architecture

[William C. <wc...@nc...>]

I wrote up a simple outline of steps to provide basic TIMER_INT OProfile 
support to the 2.5 kernel. Comments on them? I would think this would be 
something that would end up in an "OProfile Internals" manual.

  -Will



List of things need to do for minimal oprofile timer interrupt support
for platform for 2.5 kernel

1) create arch/processor/oprofile directory
2) put arch/processor/oprofile/Makefile
  	arch/processor/oprofile/Kconfig
	arch/processor/oprofile/init.c
3) Add to arch/processor/Kconfig just before "Kernel hacking" section:

source "arch/processor/oprofile/Kconfig"

4) Add to arch/processor/Makefile:

# must be linked after kernel/
drivers-$(CONFIG_OPROFILE)              += arch/processor/oprofile/


5) Modify arch/processor/kernel/timer.c to record oprofile samples

6) Adding support for lookup_dcookie.
    Add __NR_lookup_dcookie entry to include/asm-processor/unistd.h
    May also need additional support in arch/processor/kernel for
    processors that have 64-bit kernel and 32-bit user space, e.g. ppc64.
    Need to add lookup_dcookie entry to syscall table.


7) For older 2.4 kernel you will need to implement cpu_possible() for
the oprofile driver.


8) For the user space oprofile need to add appropriate
__NR_lookup_dcookie to oprofile/daemon/opd_cookie.h