Re: [PATCH 2/4] perf_counter: provide pagefault software events

[Ingo Molnar <mingo@elte.hu>]

* Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:

> Index: linux-2.6/arch/powerpc/mm/fault.c
> ===================================================================
> --- linux-2.6.orig/arch/powerpc/mm/fault.c
> +++ linux-2.6/arch/powerpc/mm/fault.c
> @@ -29,6 +29,7 @@
>  #include <linux/module.h>
>  #include <linux/kprobes.h>
>  #include <linux/kdebug.h>
> +#include <linux/perf_counter.h>
>  
>  #include <asm/firmware.h>
>  #include <asm/page.h>
> @@ -170,6 +171,8 @@ int __kprobes do_page_fault(struct pt_re
>  		die("Weird page fault", regs, SIGSEGV);
>  	}
>  
> +	perf_swcount_event(PERF_COUNT_PAGE_FAULTS, 1, regs);

Wow, that's really nice - this way we can display a profile of 
pagefault events in KernelTop - as if it was a real cycles or 
other hw event based profile. Have you tried it out?

	Ingo