Hi TSC is needed to synchronize Intel Processor Trace (Intel PT) with perf event samples. Refer to patch 1 for more details.
There is a description of Intel PT in the Intel Architecture manuals: http://www.intel.com/content/www/us/en/processors/architectures-software-developer-manuals.html With the advent of switching perf_clock to CLOCK_MONOTONIC, it will not be possible to convert perf_clock directly to/from TSC. So add the ability to sample TSC instead. Changes in V2: perf: Sample additional clock value Rename "Architecture specific clock" to "Processor trace clock" Rename PERF_SAMPLE_CLOCK_ARCH -> PERF_SAMPLE_CLOCK_PT etc Expand commit message perf/x86: Provide TSC for PERF_SAMPLE_CLOCK_PT Rename PERF_SAMPLE_CLOCK_ARCH -> PERF_SAMPLE_CLOCK_PT etc Expand commit message Adrian Hunter (2): perf: Sample additional clock value perf/x86: Provide TSC for PERF_SAMPLE_CLOCK_PT arch/x86/include/asm/perf_event.h | 6 ++++++ arch/x86/kernel/cpu/perf_event.c | 10 ++++++++++ include/linux/perf_event.h | 3 ++- include/uapi/linux/perf_event.h | 19 +++++++++++++++++-- kernel/events/core.c | 30 ++++++++++++++++++++++++++++++ kernel/events/internal.h | 4 ++++ 6 files changed, 69 insertions(+), 3 deletions(-) Regards Adrian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
