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>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index fdd33aa..f5fc56b 100644 (file)
--- 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 df5256b..644a8b5 100644 (file)
--- 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 b5cb047..40aa300 100644 (file)
--- 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 4dd986d..41e0b8a 100644 (file)
--- 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 519d04a..ac31858 100644 (file)
--- 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);