On 26/05/2022 16:23, Arnaldo Carvalho de Melo wrote:

Em Wed, May 25, 2022 at 04:41:09PM +0100, James Clark escreveu:

quoted

Changes since v2:
  * Add commit to fix header include path to use Perf's copy
  * Apply Leo's review tags

When SVE registers are pushed onto the stack the VG register is required to
unwind because the stack offsets would vary by the SVE register width at the
time when the sample was taken.

The patches ("[PATCH v2 0/2] perf: arm64: Kernel support for Dwarf unwinding
through SVE functions") add support for sampling the VG register to the kernel
and the docs. This is the patchset to add support to userspace perf.

A small change is also required to libunwind or libdw depending on which
unwinder is used, and these will be published later. Without these changes Perf
continues to work with both libraries, although the VG register is still not
used for unwinding. 

Thanks, applied.

- Arnaldo

Hi Arnaldo,

Will has applied the kernel side here:
https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/commit/?h=for-next/perf&id=cbb0c02caf4bd98b9e0cd6d7420734b8e9a35703

There was a small change in the formatting in perf_regs.h, but the
values are all the same. So in theory it's fine to leave Perf's copy
until the next update, although it is a bit weird.

Thanks
James

quoted

Thanks
James

James Clark (5):
  perf tools: arm64: Use perf's copy of kernel headers
  perf tools: arm64: Copy perf_regs.h from the kernel
  perf tools: Use dynamic register set for Dwarf unwind
  perf tools: arm64: Decouple Libunwind register names from Perf
  perf tools: arm64: Add support for VG register

 tools/arch/arm64/include/uapi/asm/perf_regs.h |  7 +-
 tools/perf/arch/arm64/util/perf_regs.c        | 34 +++++++++
 tools/perf/arch/arm64/util/unwind-libunwind.c | 73 +------------------
 tools/perf/util/evsel.c                       |  2 +-
 tools/perf/util/libunwind/arm64.c             |  2 +-
 tools/perf/util/perf_regs.c                   |  2 +
 6 files changed, 46 insertions(+), 74 deletions(-)

-- 
2.28.0

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel