Re: [RFC GIT PULL] hw-breakpoints: Rewrite on top of perf counters

Ingo Molnar
2009-09-10T17:24:11Z

* Paul Mackerras <paulus@samba.org> wrote:

> Frederic Weisbecker writes:
>
> > This is a rewrite of the hardware breakpoints on top of perf counters.
>
> On powerpc, it doesn't build. I get:
>
> CC kernel/perf_counter.o
> kernel/perf_counter.c:31:31: error: asm/hw_breakpoint.h: No such file or directory
> kernel/perf_counter.c: In function 'bp_perf_counter_init':
> kernel/perf_counter.c:3964: error: implicit declaration of function 'register_perf_hw_breakpoint'
> kernel/perf_counter.c:3966: error: implicit declaration of function '__register_perf_hw_breakpoint'
> kernel/perf_counter.c:3968: error: 'perf_ops_bp' undeclared (first use in this function)
> kernel/perf_counter.c:3968: error: (Each undeclared identifier is reported only once
> kernel/perf_counter.c:3968: error: for each function it appears in.)
> make[2]: *** [kernel/perf_counter.o] Error 1
> make[1]: *** [kernel] Error 2
> make: *** [sub-make] Error 2
>
> Seems like every architecture now needs an asm/hw_breakpoint.h.
> What is the minimum required in that file? Looks like we would
> require a perf_ops_bp, at least.
>
> Could you please either arrange things so that architectures that
> don't have hardware breakpoints hooked up to perf_counters don't
> need an asm/hw_breakpoint.h, or add minimal versions of that file
> for every architecture, so as not to break bisection
> unnecessarily?

I'd prefer the former - i.e. dont touch architectures that dont
support it yet.

Ingo