Re: [PATCH 2/6] oprofile/x86: add regs->ip to oprofile trace

From: Robert Richter
Date: Tue Aug 30 2016 - 07:30:10 EST


On 24.08.16 11:50:15, Josh Poimboeuf wrote:
> dump_trace() doesn't add the interrupted instruction's address to the
> trace, so add it manually. This makes the profile more useful, and also
> makes it more consistent with what perf profiling does.
>
> Cc: Robert Richter <rric@xxxxxxxxxx>
> Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> ---
> arch/x86/oprofile/backtrace.c | 13 ++++++++++---
> 1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c
> index cb31a44..2ef6c8b 100644
> --- a/arch/x86/oprofile/backtrace.c
> +++ b/arch/x86/oprofile/backtrace.c
> @@ -114,9 +114,16 @@ x86_backtrace(struct pt_regs * const regs, unsigned int depth)
>
> if (!user_mode(regs)) {
> unsigned long stack = kernel_stack_pointer(regs);
> - if (depth)
> - dump_trace(NULL, regs, (unsigned long *)stack, 0,
> - &backtrace_ops, &depth);
> +
> + if (!depth)
> + return;
> +
> + oprofile_add_trace(regs->ip);
> + if (!--depth)
> + return;
> +
> + dump_trace(NULL, regs, (unsigned long *)stack, 0,
> + &backtrace_ops, &depth);

Acked-by: Robert Richter <rric@xxxxxxxxxx>

Adding oprofile-list in case someone has objections since this may
break userland tools.

Ingo, please apply the patch to tip once this series is ok to you.

Thanks,

-Robert

> return;
> }
>
> --
> 2.7.4
>