Re: [PATCH RFC v1 0/4] perf: Introduce extended syscall error reporting

[Ingo Molnar <mingo@kernel.org>]

* Peter Zijlstra <peterz@infradead.org> wrote:

> On Fri, Jul 24, 2015 at 02:45:55PM +0300, Alexander Shishkin wrote:
> > Hi Peter and Ingo and everybody,
> > 
> > Here's my second stab at improving perf's error reporting by attaching
> > arbitrary strings to the integer error codes. This is largely based
> > off of the previous email thread [1].
> > 
> > This time around, I employed a linker trick to convert the structures
> > containing extended error information into integers, which are then
> > made to look just like normal error codes so that IS_ERR_VALUE() and
> > friends would still work correctly on them. So no extra pointers in
> > the struct perf_event or anywhere else; the extended error codes are
> > passed around like normal error codes. They only need to be converted
> > in syscalls' topmost return statements. This is done in 1/4.
> > 
> > Then, 2/4 illustrates how error sites can be extended to include more
> > information such as file names and line numbers [1].
> > 
> > The other two patches add perf_err() annotation to a few semi-randomly
> > picked places in perf core (3/4) and x86 bits (4/4).
> 
> Looks generally ok to me. Thanks for doing this.

I like this too.

Alexander, mind sending a finalized, signed off version?

Thanks,

	Ingo