• Kan Liang's avatar
    perf tsc: Add arch TSC frequency information · bc2373a5
    Kan Liang authored
    The TSC frequency information is required for the event metrics with the
    literal, system_tsc_freq. For the newer Intel platform, the TSC
    frequency information can be retrieved from the CPUID leaf 0x15.  If the
    TSC frequency information isn't present the /proc/cpuinfo approach is
    used.
    
    Refactor cpuid() for this use. Note, the previous stack pushing/popping
    approach was broken on x86-64 that has stack red zones that would be
    clobbered.
    
    Committer testing:
    
    Before:
    
      $ perf record sleep 0.0001
      [ perf record: Woken up 1 times to write data ]
      $ perf report --header-only |& grep cpuid
      # cpuid : AuthenticAMD,25,33,0
      $
    
    After the patch:
    
      $ perf record sleep 0.0001
      [ perf record: Woken up 1 times to write data ]
      [ perf record: Captured and wrote 0.002 MB perf.data (8 samples) ]
      $ perf report --header-only |& grep cpuid
      # cpuid : AuthenticAMD,25,33,0
      $
    Signed-off-by: default avatarKan Liang <kan.liang@linux.intel.com>
    Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
    Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
    Cc: Andi Kleen <ak@linux.intel.com>
    Cc: Caleb Biggers <caleb.biggers@intel.com>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: James Clark <james.clark@arm.com>
    Cc: Jiri Olsa <jolsa@kernel.org>
    Cc: John Garry <john.garry@huawei.com>
    Cc: Kshipra Bopardikar <kshipra.bopardikar@intel.com>
    Cc: Mark Rutland <mark.rutland@arm.com>
    Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
    Cc: Namhyung Kim <namhyung@kernel.org>
    Cc: Perry Taylor <perry.taylor@intel.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Stephane Eranian <eranian@google.com>
    Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
    Link: https://lore.kernel.org/r/20220718164312.3994191-2-irogers@google.comSigned-off-by: default avatarIan Rogers <irogers@google.com>
    Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    bc2373a5
tsc.h 710 Bytes