Add common code to generate ENOTSUPP at event creation time if an architecture attempts to create a sampled event and PERF_PMU_NO_INTERRUPT is set.
This adds a new pmu->capabilities flag. Initially we only support PERF_PMU_NO_INTERRUPT (to indicate a PMU has no support for generating hardware interrupts) but there are other capabilities that can be added later. Signed-off-by: Vince Weaver <[email protected]> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 3356abc..2164763 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -251,9 +251,20 @@ struct pmu { * flush branch stack on context-switches (needed in cpu-wide mode) */ void (*flush_branch_stack) (void); + + /* + * various common per-pmu feature flags + */ + int capabilities; + }; /** + * struct pmu->capabilites flags + */ +#define PERF_PMU_NO_INTERRUPT 1 + +/** * enum perf_event_active_state - the states of a event */ enum perf_event_active_state { diff --git a/kernel/events/core.c b/kernel/events/core.c index f83a71a..f5d8554 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7072,6 +7072,13 @@ SYSCALL_DEFINE5(perf_event_open, } } + if (is_sampling_event(event)) { + if (event->pmu->capabilities & PERF_PMU_NO_INTERRUPT) { + err = -ENOTSUPP; + goto err_alloc; + } + } + account_event(event); /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
