Re: [PATCH 09/14] perf, x86: use LBR for PEBS IP+1 fixup

Peter Zijlstra
2010-03-04T17:54:27Z

On Thu, 2010-03-04 at 11:21 -0500, Masami Hiramatsu wrote:
> Peter Zijlstra wrote:

> > +#define perf_misc_flags(regs) \
> > +({ int misc = 0; \
> > + if (user_mode(regs)) \
> > + misc |= PERF_RECORD_MISC_USER; \
> > + else \
> > + misc |= PERF_RECORD_MISC_KERNEL; \
> > + if (regs->flags & PERF_EFLAGS_EXACT) \
> > + misc |= PERF_RECORD_MISC_EXACT; \
> > + misc; })
> > +
> > +#define perf_instruction_pointer(regs) ((regs)->ip)
>
> Hmm, why don't you use instruction_pointer() defined in asm/ptrace.h?
> And I couldn't find any user of this macro in this patch...

perf_instruction_pointer() is used in kernel/perf_event.c, and yeah I
could have used instruction_pointer() but that's yet another wrapper.

Anyway, Yanmin is poking at doing kvm-guest profiling and will likely
rewrite all of the perf_misc() and perf_instruction_pointer() stuff
soon.