X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=kernel%2Ftrace%2Ftrace_sched_switch.c;h=cb817a209aa005d9b151b79e2ef52b48178dffd4;hb=b380b0d4f7dffcc235c0facefa537d4655619101;hp=b738eaca1dbe8a035284bc79cf4daabe42f9955c;hpb=e309b41dd65aa953f86765eeeecc941d8e1e8b8f;p=karo-tx-linux.git diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index b738eaca1dbe..cb817a209aa0 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -16,16 +16,22 @@ static struct trace_array *ctx_trace; static int __read_mostly tracer_enabled; +static atomic_t sched_ref; static void -ctx_switch_func(struct task_struct *prev, struct task_struct *next) +sched_switch_func(void *private, void *__rq, struct task_struct *prev, + struct task_struct *next) { - struct trace_array *tr = ctx_trace; + struct trace_array **ptr = private; + struct trace_array *tr = *ptr; struct trace_array_cpu *data; unsigned long flags; long disabled; int cpu; + tracing_record_cmdline(prev); + tracing_record_cmdline(next); + if (!tracer_enabled) return; @@ -41,20 +47,83 @@ ctx_switch_func(struct task_struct *prev, struct task_struct *next) local_irq_restore(flags); } -void ftrace_ctx_switch(struct task_struct *prev, struct task_struct *next) +static notrace void +sched_switch_callback(void *probe_data, void *call_data, + const char *format, va_list *args) { - tracing_record_cmdline(prev); + struct task_struct *prev; + struct task_struct *next; + struct rq *__rq; + + if (!atomic_read(&sched_ref)) + return; + + /* skip prev_pid %d next_pid %d prev_state %ld */ + (void)va_arg(*args, int); + (void)va_arg(*args, int); + (void)va_arg(*args, long); + __rq = va_arg(*args, typeof(__rq)); + prev = va_arg(*args, typeof(prev)); + next = va_arg(*args, typeof(next)); /* * If tracer_switch_func only points to the local * switch func, it still needs the ptr passed to it. */ - ctx_switch_func(prev, next); + sched_switch_func(probe_data, __rq, prev, next); +} - /* - * Chain to the wakeup tracer (this is a NOP if disabled): - */ - wakeup_sched_switch(prev, next); +static void +wakeup_func(void *private, void *__rq, struct task_struct *wakee, struct + task_struct *curr) +{ + struct trace_array **ptr = private; + struct trace_array *tr = *ptr; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int cpu; + + if (!tracer_enabled) + return; + + tracing_record_cmdline(curr); + + local_irq_save(flags); + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; + disabled = atomic_inc_return(&data->disabled); + + if (likely(disabled == 1)) + tracing_sched_wakeup_trace(tr, data, wakee, curr, flags); + + atomic_dec(&data->disabled); + local_irq_restore(flags); +} + +static notrace void +wake_up_callback(void *probe_data, void *call_data, + const char *format, va_list *args) +{ + struct task_struct *curr; + struct task_struct *task; + struct rq *__rq; + + if (likely(!tracer_enabled)) + return; + + /* Skip pid %d state %ld */ + (void)va_arg(*args, int); + (void)va_arg(*args, long); + /* now get the meat: "rq %p task %p rq->curr %p" */ + __rq = va_arg(*args, typeof(__rq)); + task = va_arg(*args, typeof(task)); + curr = va_arg(*args, typeof(curr)); + + tracing_record_cmdline(task); + tracing_record_cmdline(curr); + + wakeup_func(probe_data, __rq, task, curr); } static void sched_switch_reset(struct trace_array *tr) @@ -67,15 +136,105 @@ static void sched_switch_reset(struct trace_array *tr) tracing_reset(tr->data[cpu]); } +static int tracing_sched_register(void) +{ + int ret; + + ret = marker_probe_register("kernel_sched_wakeup", + "pid %d state %ld ## rq %p task %p rq->curr %p", + wake_up_callback, + &ctx_trace); + if (ret) { + pr_info("wakeup trace: Couldn't add marker" + " probe to kernel_sched_wakeup\n"); + return ret; + } + + ret = marker_probe_register("kernel_sched_wakeup_new", + "pid %d state %ld ## rq %p task %p rq->curr %p", + wake_up_callback, + &ctx_trace); + if (ret) { + pr_info("wakeup trace: Couldn't add marker" + " probe to kernel_sched_wakeup_new\n"); + goto fail_deprobe; + } + + ret = marker_probe_register("kernel_sched_schedule", + "prev_pid %d next_pid %d prev_state %ld " + "## rq %p prev %p next %p", + sched_switch_callback, + &ctx_trace); + if (ret) { + pr_info("sched trace: Couldn't add marker" + " probe to kernel_sched_schedule\n"); + goto fail_deprobe_wake_new; + } + + return ret; +fail_deprobe_wake_new: + marker_probe_unregister("kernel_sched_wakeup_new", + wake_up_callback, + &ctx_trace); +fail_deprobe: + marker_probe_unregister("kernel_sched_wakeup", + wake_up_callback, + &ctx_trace); + return ret; +} + +static void tracing_sched_unregister(void) +{ + marker_probe_unregister("kernel_sched_schedule", + sched_switch_callback, + &ctx_trace); + marker_probe_unregister("kernel_sched_wakeup_new", + wake_up_callback, + &ctx_trace); + marker_probe_unregister("kernel_sched_wakeup", + wake_up_callback, + &ctx_trace); +} + +static void tracing_start_sched_switch(void) +{ + long ref; + + ref = atomic_inc_return(&sched_ref); + if (ref == 1) + tracing_sched_register(); +} + +static void tracing_stop_sched_switch(void) +{ + long ref; + + ref = atomic_dec_and_test(&sched_ref); + if (ref) + tracing_sched_unregister(); +} + +void tracing_start_cmdline_record(void) +{ + tracing_start_sched_switch(); +} + +void tracing_stop_cmdline_record(void) +{ + tracing_stop_sched_switch(); +} + static void start_sched_trace(struct trace_array *tr) { sched_switch_reset(tr); + tracing_start_cmdline_record(); tracer_enabled = 1; } static void stop_sched_trace(struct trace_array *tr) { tracer_enabled = 0; + tracing_stop_cmdline_record(); } static void sched_switch_trace_init(struct trace_array *tr) @@ -114,6 +273,14 @@ static struct tracer sched_switch_trace __read_mostly = __init static int init_sched_switch_trace(void) { + int ret = 0; + + if (atomic_read(&sched_ref)) + ret = tracing_sched_register(); + if (ret) { + pr_info("error registering scheduler trace\n"); + return ret; + } return register_tracer(&sched_switch_trace); } device_initcall(init_sched_switch_trace);