Linux 3.14 (in commit bad7192b842c83e580747ca57104dd51fe08c223) changes the perf_event PERF_EVENT_IOC_PERIOD ioctl() behavior on all architectures to update immediately, to match the behavior found on ARM. Signed-off-by: Vince Weaver <vincent.weaver@xxxxxxxxx> diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2 index 30a2168..fa99d25 100644 --- a/man2/perf_event_open.2 +++ b/man2/perf_event_open.2 @@ -2191,9 +2191,11 @@ reset, even if the event specified is not the group leader .TP .B PERF_EVENT_IOC_PERIOD This updates the overflow period for the event. -On most architectures the new period does not take effect until -after the next overflow happens; -on ARM since Linux 3.7 the period is updated immediately. + +Since Linux 3.7 (on ARM) and Linux 3.14 (all other architectures) +the new period takes effect immediately. +On older kernels the new period did not take effect until +after the next overflow. The argument is a pointer to a 64-bit value containing the desired new period. -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
