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authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>2014-01-14 09:32:58 -0500
committerSteven Rostedt <rostedt@goodmis.org>2014-04-21 13:59:29 -0400
commit02f2f7646fd5d0482e805d728601e8e4305ad56f (patch)
tree345ca10d0e605a4b68d8146e5066dc0b18e3ec76 /kernel/trace/trace_irqsoff.c
parent65daaca7c6dac4db0ef64f2baac0e448cf5d847f (diff)
tracing: Allow irq/preempt tracers to be used by instances
The irqsoff, preemptoff and preemptirqsoff tracers can now be used by instances. But they may only be used by one instance at a time (including the top level directory). This allows multiple tracers to run while the irqsoff (and friends) tracer is running simultaneously. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_irqsoff.c')
-rw-r--r--kernel/trace/trace_irqsoff.c24
1 files changed, 17 insertions, 7 deletions
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 40aa300d3491..9bb104f748d0 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -597,8 +597,13 @@ static void stop_irqsoff_tracer(struct trace_array *tr, int graph)
unregister_irqsoff_function(tr, graph);
}
-static void __irqsoff_tracer_init(struct trace_array *tr)
+static bool irqsoff_busy;
+
+static int __irqsoff_tracer_init(struct trace_array *tr)
{
+ if (irqsoff_busy)
+ return -EBUSY;
+
save_flags = trace_flags;
/* non overwrite screws up the latency tracers */
@@ -617,6 +622,9 @@ static void __irqsoff_tracer_init(struct trace_array *tr)
if (start_irqsoff_tracer(tr, (tr->flags & TRACE_ARRAY_FL_GLOBAL &&
is_graph())))
printk(KERN_ERR "failed to start irqsoff tracer\n");
+
+ irqsoff_busy = true;
+ return 0;
}
static void irqsoff_tracer_reset(struct trace_array *tr)
@@ -629,6 +637,8 @@ static void irqsoff_tracer_reset(struct trace_array *tr)
set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, lat_flag);
set_tracer_flag(tr, TRACE_ITER_OVERWRITE, overwrite_flag);
ftrace_reset_array_ops(tr);
+
+ irqsoff_busy = false;
}
static void irqsoff_tracer_start(struct trace_array *tr)
@@ -646,8 +656,7 @@ static int irqsoff_tracer_init(struct trace_array *tr)
{
trace_type = TRACER_IRQS_OFF;
- __irqsoff_tracer_init(tr);
- return 0;
+ return __irqsoff_tracer_init(tr);
}
static struct tracer irqsoff_tracer __read_mostly =
{
@@ -667,6 +676,7 @@ static struct tracer irqsoff_tracer __read_mostly =
#endif
.open = irqsoff_trace_open,
.close = irqsoff_trace_close,
+ .allow_instances = true,
.use_max_tr = true,
};
# define register_irqsoff(trace) register_tracer(&trace)
@@ -679,8 +689,7 @@ static int preemptoff_tracer_init(struct trace_array *tr)
{
trace_type = TRACER_PREEMPT_OFF;
- __irqsoff_tracer_init(tr);
- return 0;
+ return __irqsoff_tracer_init(tr);
}
static struct tracer preemptoff_tracer __read_mostly =
@@ -701,6 +710,7 @@ static struct tracer preemptoff_tracer __read_mostly =
#endif
.open = irqsoff_trace_open,
.close = irqsoff_trace_close,
+ .allow_instances = true,
.use_max_tr = true,
};
# define register_preemptoff(trace) register_tracer(&trace)
@@ -715,8 +725,7 @@ static int preemptirqsoff_tracer_init(struct trace_array *tr)
{
trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;
- __irqsoff_tracer_init(tr);
- return 0;
+ return __irqsoff_tracer_init(tr);
}
static struct tracer preemptirqsoff_tracer __read_mostly =
@@ -737,6 +746,7 @@ static struct tracer preemptirqsoff_tracer __read_mostly =
#endif
.open = irqsoff_trace_open,
.close = irqsoff_trace_close,
+ .allow_instances = true,
.use_max_tr = true,
};