Re: [PATCH] perf: ARM: Record the user-mode PC in the call chain.

From: Jed Davis
Date: Wed Jun 19 2013 - 23:17:14 EST


On Tue, Jun 18, 2013 at 02:13:19PM +0100, Will Deacon wrote:
> On Fri, Jun 14, 2013 at 12:21:11AM +0100, Jed Davis wrote:
> > With this change, we no longer lose the innermost entry in the user-mode
> > part of the call chain. See also the x86 port, which includes the ip.
> >
> > It's possible to partially work around this problem by post-processing
> > the data to use the PERF_SAMPLE_IP value, but this works only if the CPU
> > wasn't in the kernel when the sample was taken.
>
> Thanks. I guess we need something similar for arm64 too. Could you cook a
> similar patch please?

Done (and tested, on the ARM V8 Foundation Model).

It looked as if the powerpc and sparc ports might have similar issues,
but I haven't checked on them yet.

--Jed

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/