tracing: Move tracing_max_latency into trace_array

In preparation for letting the latency tracers be used by instances,
remove the global tracing_max_latency variable and add a max_latency
field to the trace_array that the latency tracers will now use.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

5 files changed, 33 insertions, 36 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index fdd33aacdf05..f5fc56bf0227 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -982,8 +982,6 @@ static arch_spinlock_t ftrace_max_lock =
 unsigned long __read_mostly     tracing_thresh;
 
 #ifdef CONFIG_TRACER_MAX_TRACE
-unsigned long __read_mostly     tracing_max_latency;
-
 /*
  * Copy the new maximum trace into the separate maximum-trace
  * structure. (this way the maximum trace is permanently saved,
@@ -1000,7 +998,7 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
         max_buf->cpu = cpu;
         max_buf->time_start = data->preempt_timestamp;
 
-        max_data->saved_latency = tracing_max_latency;
+        max_data->saved_latency = tr->max_latency;
         max_data->critical_start = data->critical_start;
         max_data->critical_end = data->critical_end;
 
@@ -6328,6 +6326,11 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
         trace_create_file("tracing_on", 0644, d_tracer,
                           tr, &rb_simple_fops);
 
+#ifdef CONFIG_TRACER_MAX_TRACE
+        trace_create_file("tracing_max_latency", 0644, d_tracer,
+                        &tr->max_latency, &tracing_max_lat_fops);
+#endif
+
         if (ftrace_create_function_files(tr, d_tracer))
                 WARN(1, "Could not allocate function filter files");
 
@@ -6353,11 +6356,6 @@ static __init int tracer_init_debugfs(void)
 
         init_tracer_debugfs(&global_trace, d_tracer);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-        trace_create_file("tracing_max_latency", 0644, d_tracer,
-                        &tracing_max_latency, &tracing_max_lat_fops);
-#endif
-
         trace_create_file("tracing_thresh", 0644, d_tracer,
                         &tracing_thresh, &tracing_max_lat_fops);
 
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index df5256be64cd..644a8b533e1d 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -190,6 +190,7 @@ struct trace_array {
          */
         struct trace_buffer     max_buffer;
         bool                    allocated_snapshot;
+        unsigned long           max_latency;
 #endif
         int                     buffer_disabled;
 #ifdef CONFIG_FTRACE_SYSCALLS
@@ -599,8 +600,6 @@ extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 extern unsigned long tracing_thresh;
 
 #ifdef CONFIG_TRACER_MAX_TRACE
-extern unsigned long tracing_max_latency;
-
 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 void update_max_tr_single(struct trace_array *tr,
                           struct task_struct *tsk, int cpu);
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index b5cb047df3e9..40aa300d3491 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -170,7 +170,7 @@ irqsoff_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
         for_each_possible_cpu(cpu)
                 per_cpu(tracing_cpu, cpu) = 0;
 
-        tracing_max_latency = 0;
+        tr->max_latency = 0;
         tracing_reset_online_cpus(&irqsoff_trace->trace_buffer);
 
         return start_irqsoff_tracer(irqsoff_trace, set);
@@ -297,13 +297,13 @@ static void irqsoff_print_header(struct seq_file *s)
 /*
  * Should this new latency be reported/recorded?
  */
-static int report_latency(cycle_t delta)
+static int report_latency(struct trace_array *tr, cycle_t delta)
 {
         if (tracing_thresh) {
                 if (delta < tracing_thresh)
                         return 0;
         } else {
-                if (delta <= tracing_max_latency)
+                if (delta <= tr->max_latency)
                         return 0;
         }
         return 1;
@@ -327,13 +327,13 @@ check_critical_timing(struct trace_array *tr,
 
         pc = preempt_count();
 
-        if (!report_latency(delta))
+        if (!report_latency(tr, delta))
                 goto out;
 
         raw_spin_lock_irqsave(&max_trace_lock, flags);
 
         /* check if we are still the max latency */
-        if (!report_latency(delta))
+        if (!report_latency(tr, delta))
                 goto out_unlock;
 
         __trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
@@ -346,7 +346,7 @@ check_critical_timing(struct trace_array *tr,
         data->critical_end = parent_ip;
 
         if (likely(!is_tracing_stopped())) {
-                tracing_max_latency = delta;
+                tr->max_latency = delta;
                 update_max_tr_single(tr, current, cpu);
         }
 
@@ -605,7 +605,7 @@ static void __irqsoff_tracer_init(struct trace_array *tr)
         set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
         set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1);
 
-        tracing_max_latency = 0;
+        tr->max_latency = 0;
         irqsoff_trace = tr;
         /* make sure that the tracer is visible */
         smp_wmb();
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 4dd986defa60..41e0b8aa78ed 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -218,7 +218,7 @@ wakeup_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
         stop_func_tracer(tr, !set);
 
         wakeup_reset(wakeup_trace);
-        tracing_max_latency = 0;
+        tr->max_latency = 0;
 
         return start_func_tracer(tr, set);
 }
@@ -344,13 +344,13 @@ static void wakeup_print_header(struct seq_file *s)
 /*
  * Should this new latency be reported/recorded?
  */
-static int report_latency(cycle_t delta)
+static int report_latency(struct trace_array *tr, cycle_t delta)
 {
         if (tracing_thresh) {
                 if (delta < tracing_thresh)
                         return 0;
         } else {
-                if (delta <= tracing_max_latency)
+                if (delta <= tr->max_latency)
                         return 0;
         }
         return 1;
@@ -418,11 +418,11 @@ probe_wakeup_sched_switch(void *ignore,
         T1 = ftrace_now(cpu);
         delta = T1-T0;
 
-        if (!report_latency(delta))
+        if (!report_latency(wakeup_trace, delta))
                 goto out_unlock;
 
         if (likely(!is_tracing_stopped())) {
-                tracing_max_latency = delta;
+                wakeup_trace->max_latency = delta;
                 update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu);
         }
 
@@ -609,7 +609,7 @@ static int __wakeup_tracer_init(struct trace_array *tr)
         set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
         set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1);
 
-        tracing_max_latency = 0;
+        tr->max_latency = 0;
         wakeup_trace = tr;
         ftrace_init_array_ops(tr, wakeup_tracer_call);
         start_wakeup_tracer(tr);
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 519d04affe38..ac3185892960 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -807,7 +807,7 @@ out:
 int
 trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
 {
-        unsigned long save_max = tracing_max_latency;
+        unsigned long save_max = tr->max_latency;
         unsigned long count;
         int ret;
 
@@ -819,7 +819,7 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
         }
 
         /* reset the max latency */
-        tracing_max_latency = 0;
+        tr->max_latency = 0;
         /* disable interrupts for a bit */
         local_irq_disable();
         udelay(100);
@@ -846,7 +846,7 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
                 ret = -1;
         }
 
-        tracing_max_latency = save_max;
+        tr->max_latency = save_max;
 
         return ret;
 }
@@ -856,7 +856,7 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
 int
 trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
 {
-        unsigned long save_max = tracing_max_latency;
+        unsigned long save_max = tr->max_latency;
         unsigned long count;
         int ret;
 
@@ -881,7 +881,7 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
         }
 
         /* reset the max latency */
-        tracing_max_latency = 0;
+        tr->max_latency = 0;
         /* disable preemption for a bit */
         preempt_disable();
         udelay(100);
@@ -908,7 +908,7 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
                 ret = -1;
         }
 
-        tracing_max_latency = save_max;
+        tr->max_latency = save_max;
 
         return ret;
 }
@@ -918,7 +918,7 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
 int
 trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr)
 {
-        unsigned long save_max = tracing_max_latency;
+        unsigned long save_max = tr->max_latency;
         unsigned long count;
         int ret;
 
@@ -943,7 +943,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
         }
 
         /* reset the max latency */
-        tracing_max_latency = 0;
+        tr->max_latency = 0;
 
         /* disable preemption and interrupts for a bit */
         preempt_disable();
@@ -978,7 +978,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
         }
 
         /* do the test by disabling interrupts first this time */
-        tracing_max_latency = 0;
+        tr->max_latency = 0;
         tracing_start();
         trace->start(tr);
 
@@ -1009,7 +1009,7 @@ out:
         tracing_start();
 out_no_start:
         trace->reset(tr);
-        tracing_max_latency = save_max;
+        tr->max_latency = save_max;
 
         return ret;
 }
@@ -1062,7 +1062,7 @@ static int trace_wakeup_test_thread(void *data)
 int
 trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
 {
-        unsigned long save_max = tracing_max_latency;
+        unsigned long save_max = tr->max_latency;
         struct task_struct *p;
         struct completion is_ready;
         unsigned long count;
@@ -1088,7 +1088,7 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
         }
 
         /* reset the max latency */
-        tracing_max_latency = 0;
+        tr->max_latency = 0;
 
         while (p->on_rq) {
                 /*
@@ -1118,7 +1118,7 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
         trace->reset(tr);
         tracing_start();
 
-        tracing_max_latency = save_max;
+        tr->max_latency = save_max;
 
         /* kill the thread */
         kthread_stop(p);