By popular request, provide means to log a timestamp along with the counter overflow event. Signed-off-by: Peter Zijlstra --- include/linux/perf_counter.h | 2 ++ kernel/perf_counter.c | 14 ++++++++++++++ 2 files changed, 16 insertions(+) Index: linux-2.6/include/linux/perf_counter.h =================================================================== --- linux-2.6.orig/include/linux/perf_counter.h +++ linux-2.6/include/linux/perf_counter.h @@ -102,6 +102,7 @@ enum perf_counter_record_format { PERF_RECORD_TID = 1U << 1, PERF_RECORD_GROUP = 1U << 2, PERF_RECORD_CALLCHAIN = 1U << 3, + PERF_RECORD_TIME = 1U << 4, }; /* @@ -221,6 +222,7 @@ enum perf_event_type { __PERF_EVENT_TID = PERF_RECORD_TID, __PERF_EVENT_GROUP = PERF_RECORD_GROUP, __PERF_EVENT_CALLCHAIN = PERF_RECORD_CALLCHAIN, + __PERF_EVENT_TIME = PERF_RECORD_TIME, }; #ifdef __KERNEL__ Index: linux-2.6/kernel/perf_counter.c =================================================================== --- linux-2.6.orig/kernel/perf_counter.c +++ linux-2.6/kernel/perf_counter.c @@ -1823,6 +1823,7 @@ static void perf_counter_output(struct p } group_entry; struct perf_callchain_entry *callchain = NULL; int callchain_size = 0; + u64 time; header.type = PERF_EVENT_COUNTER_OVERFLOW; header.size = sizeof(header); @@ -1859,6 +1860,16 @@ static void perf_counter_output(struct p } } + if (record_type & PERF_RECORD_TIME) { + /* + * Maybe do better on x86 and provide cpu_clock_nmi() + */ + time = sched_clock(); + + header.type |= __PERF_EVENT_TIME; + header.size += sizeof(u64); + } + ret = perf_output_begin(&handle, counter, header.size, nmi); if (ret) return; @@ -1892,6 +1903,9 @@ static void perf_counter_output(struct p if (callchain) perf_output_copy(&handle, callchain, callchain_size); + if (record_type & PERF_RECORD_TIME) + perf_output_put(&handle, time); + perf_output_end(&handle); } -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/