History log of /linux-master/tools/perf/arch/x86/util/cpuid.h
Revision Date Author Comments
# bc2373a5 18-Jul-2022 Kan Liang <kan.liang@linux.intel.com>

perf tsc: Add arch TSC frequency information

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: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Arnaldo 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.com
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>