• Will Deacon's avatar
    arm64: perf: use architected event for CPU cycle counter · f46f979f
    Will Deacon authored
    We currently use a fake event encoding (0xFF) to indicate CPU cycles so
    that we don't waste an event counter and can target the hardware cycle
    counter instead.
    
    The problem with this approach is that the event space defined by the
    architecture permits an implementation to allocate 0xFF for some other
    event.
    
    This patch uses the architected cycle counter encoding (0x11) so that
    we avoid potentially clashing with event encodings on future CPU
    implementations.
    Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
    Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
    f46f979f
perf_event.c 33.2 KB