Hi Mark,
On 26 February 2014 00:26, Mark Wielaard <mjw(a)redhat.com> wrote:
Hi Jean,
Seems you already got your answer to the build question solved.
Yes! There is quite
a huge improvement in performance: >500% for dwarf
unwinding ;-p
On Tue, 2014-02-25 at 18:17 +0100, Jean Pihet wrote:
> The goal is to add the libdw support for perf on ARM (and later AARCH64).
Note that there is some code in elfutils git that handles .debug_frame
for ARM, but not yet code for handling EXIDX tables. For non-debug
unwinding ARM uses EXIDX tables, not .eh_frames. Handling EXIDX tables
is probably easiest done by translating them to CFI. In case you want to
do unwinding using libdw without .debug_frame available.
That is good to know. Our
use cases suppose we have the .debug_frame
section in the binaries by default and otherwise the frame pointer can
be used.
For AARCH64 there is some code available on my branch:
https://git.fedorahosted.org/cgit/elfutils.git/log/?h=mjw/aarch64-unwind
Which might or might not work. I need to get access again to a aarch64
setup to do some more testing before moving this to master.
Great! AARCH64 is next
on my plate, I surely will let you know the status.
Thx for you replies!
Jean
Cheers,
Mark