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    Subject[PATCH v3 0/2] perf: arm64: Kernel support for Dwarf unwinding through SVE functions
    Date
    Hi,

    I'm resubmitting this with a few of the changes suggested by Will on V2.

    I haven't made any changes regarding the open questions about the
    discoverability or saving the new reg and passing to output_sample()
    because I think it's best to be consistent with the implementations on
    other platforms first. I have explained in more detail on v2 [1].

    [1]: https://lore.kernel.org/lkml/5fcf1a6f-c8fb-c296-992e-18aae8874095@arm.com/

    =======

    Changes since v2:

    * Add definition for PERF_REG_EXTENDED_MASK which is needed for
    PERF_PMU_CAP_EXTENDED_REGS to work properly

    * Simplify changes to enum perf_event_arm_regs

    Changes since v1:

    * Add Mark's review tag
    * Clarify in docs that it's the SVE register length
    * Split patchset into kernel side and Perf tool changes

    =======

    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.

    These first two patches add support for sampling the VG register to the kernel
    and the docs. There is another 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
    James

    James Clark (2):
    perf: arm64: Add SVE vector granule register to user regs
    arm64/sve: Add Perf extensions documentation

    Documentation/arm64/sve.rst | 20 +++++++++++++++++
    arch/arm64/include/uapi/asm/perf_regs.h | 7 ++++++
    arch/arm64/kernel/perf_regs.c | 30 +++++++++++++++++++++++--
    drivers/perf/arm_pmu.c | 2 +-
    4 files changed, 56 insertions(+), 3 deletions(-)

    --
    2.28.0

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