On Tue, May 20, 2014 at 06:26:44PM -0700, Sukadev Bhattiprolu wrote:
SNIP
+ *
+ * The value in LR is only needed when it holds a return address. If the
+ * return address is on the stack, we should ignore the LR value.
+ *
+ * Further, when the return address is in the LR, if a new frame
On Tue, May 20, 2014 at 06:26:44PM -0700, Sukadev Bhattiprolu wrote:
SNIP
+ * TODO:
+ * Rather than returning an index into the callchain and have the
+ * caller skip that entry, we could modify the callchain in-place
+ * by putting a PERF_CONTEXT_IGNORE marker in the affected entry.
Jiri Olsa [jo...@redhat.com] wrote:
|
| yep, that sounds more clear to me.. something like below?
|
| calling callchain_dup from within arch_adjust_callchain in case
| you want to change it and returning != 0 in this case, so
| we could free the new callchain
Agree.
|
| but it might be to
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
Maynard Johnson [mpj...@us.ibm.com] wrote:
| [PATCH 1/1] powerpc/perf: Adjust callchain based on DWARF debug info
|
| Acked-by: Maynard Johnson mayna...@us.ibm.com
|
| Reviewed and tested. Thanks, Suka.
Thanks Maynard. This updated patch also fixes whitespace damage.
From: Sukadev
Ellerman
micha...@au1.ibm.com, Maynard Johnson/Rochester/IBM@IBMUS,
linuxppc-dev@lists.ozlabs.org
Date: 05/09/2014 09:46 PM
Subject: [PATCH 1/1] powerpc/perf: Adjust callchain based on DWARF debug
info
[PATCH 1/1] powerpc/perf: Adjust callchain based on DWARF debug info
Acked-by: Maynard
[PATCH 1/1] 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.
Eg: the value in the link register (LR) is needed only when
