Subject: Re: [PATCH v5 1/1] powerpc/perf: Adjust callchain based on DWARF debug info

From: Jiri Olsa <[email-masked]>
Date: Tue, 23 Sep 2014 08:59:06 +0200

On Tue, Sep 23, 2014 at 12:33:45AM +0300, Aaro Koskinen wrote:
> Hi,
> 
> On Wed, Jun 25, 2014 at 08:49:03AM -0700, Sukadev Bhattiprolu wrote:
> > powerpc/perf: Adjust callchain based on DWARF debug info
> > 
> > When saving the callchain on Power, the kernel conservatively saves excess
> > entries in the callchain. A few of these entries are needed in some cases
> > but not others. We should use the DWARF debug information to determine
> > when the entries are  needed.
> 
> This patch breaks perf compilation if DWARF support is not present.
> DWARF support is auto-detected early in the build, so IMHO either user
> should be informed to install the needed stuff, or the build should
> succeed with limited functionality.
> 
> arch/powerpc/util/skip-callchain-idx.c:13:19: fatal error: dwarf.h: No such file or directory #include <dwarf.h>
>                    ^
> compilation terminated.

looks like powerpc issue.. hows 'make -f tests/make' doing
on powerpc? It tests above scenario.

jirka