Greetings, This is a second spin of the short series posted last week: http://www.spinics.net/lists/kernel/msg1824419.html The first patch adds an additional timestamp field in the perf sample data, which can be requested for any perf event along with normal PERF_SAMPLE_TIME. Events with both values appearing periodically in the perf data allow user code to translate raw monotonic time (obtained via POSIX clock API) to sched_clock domain. Although any perf event can be used, the natural choice would be a sched_switch trace event (for processes with root permissions) or a hrtimer-based PERF_COUNT_SW_CPU_CLOCK. It didn't attract any comments previously, so is just re-posted without any changes. The second patch, functionally orthogonal but complementing the first one, builds on the ftrace "trace_maker" idea. It adds a ioctl that can be used to inject a userspace-generated data into the perf buffer. It provides base for printf-like functionality in perf world. If used with the previous patch, it can be also used to provide synchronisation points for sched vs. raw monotonic time stamps correlation. First version of the patch was taking a zero-terminated string as an argument. Now it is taking a custom structure with "type" and "size" integer fields followed by data. Type value "0" is defined as a zero-terminated string (although size, including the NULL character, must still be provided), but meaning of data for other types is of no interest for the kernel. The intention is to host a list of "well known" types (with reference parsers for them) in the user perf tool code. Pawel Moll (2): perf: Add sampling of the raw monotonic clock perf: Userspace software event and ioctl include/linux/perf_event.h | 10 +++++ include/uapi/linux/perf_event.h | 36 +++++++++++++++++- kernel/events/core.c | 81 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 126 insertions(+), 1 deletion(-) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
