From: Steven Rostedt We can find some bugs in the trace events if we stress the writes as well. The function tracer is a good way to stress the events. Signed-off-by: Steven Rostedt --- kernel/trace/trace_events.c | 80 +++++++++++++++++++++++++++++++++++++++---- 1 files changed, 73 insertions(+), 7 deletions(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 96934f0..dd3eb59 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1015,7 +1015,7 @@ static __init void event_test_stuff(void) * For every trace event defined, we will test each trace point separately, * and then by groups, and finally all trace points. */ -static __init int event_trace_self_tests(void) +static __init void event_trace_self_tests(void) { struct ftrace_event_call *call; struct event_subsystem *system; @@ -1069,7 +1069,7 @@ static __init int event_trace_self_tests(void) sysname = kstrdup(system->name, GFP_KERNEL); if (WARN_ON(!sysname)) { pr_warning("Can't allocate memory, giving up!\n"); - return 0; + return; } ret = ftrace_set_clr_event(sysname, 1); kfree(sysname); @@ -1084,7 +1084,7 @@ static __init int event_trace_self_tests(void) sysname = kstrdup(system->name, GFP_KERNEL); if (WARN_ON(!sysname)) { pr_warning("Can't allocate memory, giving up!\n"); - return 0; + return; } ret = ftrace_set_clr_event(sysname, 0); kfree(sysname); @@ -1104,14 +1104,14 @@ static __init int event_trace_self_tests(void) sysname = kmalloc(4, GFP_KERNEL); if (WARN_ON(!sysname)) { pr_warning("Can't allocate memory, giving up!\n"); - return 0; + return; } memcpy(sysname, "*:*", 4); ret = ftrace_set_clr_event(sysname, 1); if (WARN_ON_ONCE(ret)) { kfree(sysname); pr_warning("error enabling all events\n"); - return 0; + return; } event_test_stuff(); @@ -1123,14 +1123,80 @@ static __init int event_trace_self_tests(void) if (WARN_ON_ONCE(ret)) { pr_warning("error disabling all events\n"); - return 0; + return; } pr_cont("OK\n"); +} + +#ifdef CONFIG_FUNCTION_TRACER + +static DEFINE_PER_CPU(atomic_t, test_event_disable); + +static void +function_test_events_call(unsigned long ip, unsigned long parent_ip) +{ + struct ring_buffer_event *event; + struct ftrace_entry *entry; + unsigned long flags; + long disabled; + int resched; + int cpu; + int pc; + + pc = preempt_count(); + resched = ftrace_preempt_disable(); + cpu = raw_smp_processor_id(); + disabled = atomic_inc_return(&per_cpu(test_event_disable, cpu)); + + if (disabled != 1) + goto out; + + local_save_flags(flags); + + event = trace_current_buffer_lock_reserve(TRACE_FN, sizeof(*entry), + flags, pc); + if (!event) + goto out; + entry = ring_buffer_event_data(event); + entry->ip = ip; + entry->parent_ip = parent_ip; + + trace_current_buffer_unlock_commit(event, flags, pc); + + out: + atomic_dec(&per_cpu(test_event_disable, cpu)); + ftrace_preempt_enable(resched); +} + +static struct ftrace_ops trace_ops __initdata = +{ + .func = function_test_events_call, +}; + +static __init void event_trace_self_test_with_function(void) +{ + register_ftrace_function(&trace_ops); + pr_info("Running tests again, along with the function tracer\n"); + event_trace_self_tests(); + unregister_ftrace_function(&trace_ops); +} +#else +static __init void event_trace_self_test_with_function(void) +{ +} +#endif + +static __init int event_trace_self_tests_init(void) +{ + + event_trace_self_tests(); + + event_trace_self_test_with_function(); return 0; } -late_initcall(event_trace_self_tests); +late_initcall(event_trace_self_tests_init); #endif -- 1.6.2.1 -- -- 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/