ftrace: remove trace array ctrl

Impact: remove obsolete variable in trace_array structure

With the new start / stop method of ftrace, the ctrl variable
in the trace_array structure is now obsolete. Remove it.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 9e83188..5843541 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -537,7 +537,6 @@ int register_tracer(struct tracer *type)
        if (type->selftest) {
                struct tracer *saved_tracer = current_trace;
                struct trace_array *tr = &global_trace;
-               int saved_ctrl = tr->ctrl;
                int i;
                /*
                 * Run a selftest on this tracer.
@@ -550,13 +549,11 @@ int register_tracer(struct tracer *type)
                        tracing_reset(tr, i);
                }
                current_trace = type;
-               tr->ctrl = 0;
                /* the test is responsible for initializing and enabling */
                pr_info("Testing tracer %s: ", type->name);
                ret = type->selftest(type, tr);
                /* the test is responsible for resetting too */
                current_trace = saved_tracer;
-               tr->ctrl = saved_ctrl;
                if (ret) {
                        printk(KERN_CONT "FAILED!\n");
                        goto out;
@@ -966,7 +963,7 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
        int cpu;
        int pc;
 
-       if (tracing_disabled || !tr->ctrl)
+       if (tracing_disabled)
                return;
 
        pc = preempt_count();
@@ -2820,7 +2817,6 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
        unsigned long val;
        char buf[64];
        int ret;
-       struct trace_array *tr = filp->private_data;
 
        if (cnt >= sizeof(buf))
                return -EINVAL;
@@ -2840,12 +2836,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 
        mutex_lock(&trace_types_lock);
 
-       if (tr->ctrl) {
-               cnt = -EBUSY;
-               pr_info("ftrace: please disable tracing"
-                       " before modifying buffer size\n");
-               goto out;
-       }
+       tracing_stop();
 
        if (val != global_trace.entries) {
                ret = ring_buffer_resize(global_trace.buffer, val);
@@ -2878,6 +2869,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
        if (tracing_disabled)
                cnt = -ENOMEM;
  out:
+       tracing_start();
        max_tr.entries = global_trace.entries;
        mutex_unlock(&trace_types_lock);
 
@@ -2900,9 +2892,8 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 {
        char *buf;
        char *end;
-       struct trace_array *tr = &global_trace;
 
-       if (!tr->ctrl || tracing_disabled)
+       if (tracing_disabled)
                return -EINVAL;
 
        if (cnt > TRACE_BUF_SIZE)
@@ -3131,7 +3122,7 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
        unsigned long flags, irq_flags;
        int cpu, len = 0, size, pc;
 
-       if (!tr->ctrl || tracing_disabled)
+       if (tracing_disabled)
                return 0;
 
        pc = preempt_count();
@@ -3365,7 +3356,6 @@ __init static int tracer_alloc_buffers(void)
 #endif
 
        /* All seems OK, enable tracing */
-       global_trace.ctrl = 1;
        tracing_disabled = 0;
 
        atomic_notifier_chain_register(&panic_notifier_list,

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index e481eda..cfda9d2 100644 (file)
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -172,7 +172,6 @@ struct trace_iterator;
 struct trace_array {
        struct ring_buffer      *buffer;
        unsigned long           entries;
-       long                    ctrl;
        int                     cpu;
        cycle_t                 time_start;
        struct task_struct      *waiter;

diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index e980b87..8693b7a 100644 (file)
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -44,14 +44,12 @@ static void stop_function_trace(struct trace_array *tr)
 
 static void function_trace_init(struct trace_array *tr)
 {
-       if (tr->ctrl)
-               start_function_trace(tr);
+       start_function_trace(tr);
 }
 
 static void function_trace_reset(struct trace_array *tr)
 {
-       if (tr->ctrl)
-               stop_function_trace(tr);
+       stop_function_trace(tr);
 }
 
 static void function_trace_start(struct trace_array *tr)

diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index ffdf592..d919d4e 100644 (file)
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -383,15 +383,12 @@ static void __irqsoff_tracer_init(struct trace_array *tr)
        irqsoff_trace = tr;
        /* make sure that the tracer is visible */
        smp_wmb();
-
-       if (tr->ctrl)
-               start_irqsoff_tracer(tr);
+       start_irqsoff_tracer(tr);
 }
 
 static void irqsoff_tracer_reset(struct trace_array *tr)
 {
-       if (tr->ctrl)
-               stop_irqsoff_tracer(tr);
+       stop_irqsoff_tracer(tr);
 }
 
 static void irqsoff_tracer_start(struct trace_array *tr)

diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index fa9354e..51bcf37 100644 (file)
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -34,17 +34,16 @@ static void mmio_trace_init(struct trace_array *tr)
 {
        pr_debug("in %s\n", __func__);
        mmio_trace_array = tr;
-       if (tr->ctrl) {
-               mmio_reset_data(tr);
-               enable_mmiotrace();
-       }
+
+       mmio_reset_data(tr);
+       enable_mmiotrace();
 }
 
 static void mmio_trace_reset(struct trace_array *tr)
 {
        pr_debug("in %s\n", __func__);
-       if (tr->ctrl)
-               disable_mmiotrace();
+
+       disable_mmiotrace();
        mmio_reset_data(tr);
        mmio_trace_array = NULL;
 }

diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
index e3c5fbf..2ef1d22 100644 (file)
--- a/kernel/trace/trace_nop.c
+++ b/kernel/trace/trace_nop.c
@@ -32,14 +32,12 @@ static void nop_trace_init(struct trace_array *tr)
        for_each_online_cpu(cpu)
                tracing_reset(tr, cpu);
 
-       if (tr->ctrl)
-               start_nop_trace(tr);
+       start_nop_trace(tr);
 }
 
 static void nop_trace_reset(struct trace_array *tr)
 {
-       if (tr->ctrl)
-               stop_nop_trace(tr);
+       stop_nop_trace(tr);
 }
 
 struct tracer nop_trace __read_mostly =

diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 7b73fd1..be35bdf 100644 (file)
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -209,14 +209,12 @@ static void stop_sched_trace(struct trace_array *tr)
 static void sched_switch_trace_init(struct trace_array *tr)
 {
        ctx_trace = tr;
-
-       if (tr->ctrl)
-               start_sched_trace(tr);
+       start_sched_trace(tr);
 }
 
 static void sched_switch_trace_reset(struct trace_array *tr)
 {
-       if (tr->ctrl && sched_ref)
+       if (sched_ref)
                stop_sched_trace(tr);
 }
 

diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 23e54d4..983f2b1 100644 (file)
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -334,18 +334,14 @@ static void stop_wakeup_tracer(struct trace_array *tr)
 static void wakeup_tracer_init(struct trace_array *tr)
 {
        wakeup_trace = tr;
-
-       if (tr->ctrl)
-               start_wakeup_tracer(tr);
+       start_wakeup_tracer(tr);
 }
 
 static void wakeup_tracer_reset(struct trace_array *tr)
 {
-       if (tr->ctrl) {
-               stop_wakeup_tracer(tr);
-               /* make sure we put back any tasks we are tracing */
-               wakeup_reset(tr);
-       }
+       stop_wakeup_tracer(tr);
+       /* make sure we put back any tasks we are tracing */
+       wakeup_reset(tr);
 }
 
 static void wakeup_tracer_start(struct trace_array *tr)

diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 7469343..ea4e5d3 100644 (file)
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -110,7 +110,6 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
        ftrace_set_filter(func_name, strlen(func_name), 1);
 
        /* enable tracing */
-       tr->ctrl = 1;
        trace->init(tr);
 
        /* Sleep for a 1/10 of a second */
@@ -181,7 +180,6 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
        ftrace_enabled = 1;
        tracer_enabled = 1;
 
-       tr->ctrl = 1;
        trace->init(tr);
        /* Sleep for a 1/10 of a second */
        msleep(100);
@@ -224,7 +222,6 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
        int ret;
 
        /* start the tracing */
-       tr->ctrl = 1;
        trace->init(tr);
        /* reset the max latency */
        tracing_max_latency = 0;
@@ -261,7 +258,6 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
        int ret;
 
        /* start the tracing */
-       tr->ctrl = 1;
        trace->init(tr);
        /* reset the max latency */
        tracing_max_latency = 0;
@@ -298,7 +294,6 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
        int ret;
 
        /* start the tracing */
-       tr->ctrl = 1;
        trace->init(tr);
 
        /* reset the max latency */
@@ -427,7 +422,6 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
        wait_for_completion(&isrt);
 
        /* start the tracing */
-       tr->ctrl = 1;
        trace->init(tr);
        /* reset the max latency */
        tracing_max_latency = 0;
@@ -484,7 +478,6 @@ trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr
        int ret;
 
        /* start the tracing */
-       tr->ctrl = 1;
        trace->init(tr);
        /* Sleep for a 1/10 of a second */
        msleep(100);
@@ -512,7 +505,6 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr)
        int ret;
 
        /* start the tracing */
-       tr->ctrl = 1;
        trace->init(tr);
        /* Sleep for a 1/10 of a second */
        msleep(100);

diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index 8097430..05f7534 100644 (file)
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -265,14 +265,12 @@ static void stack_trace_init(struct trace_array *tr)
 {
        sysprof_trace = tr;
 
-       if (tr->ctrl)
-               start_stack_trace(tr);
+       start_stack_trace(tr);
 }
 
 static void stack_trace_reset(struct trace_array *tr)
 {
-       if (tr->ctrl)
-               stop_stack_trace(tr);
+       stop_stack_trace(tr);
 }
 
 static struct tracer stack_trace __read_mostly =