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yaml
---
r: 121268
b: refs/heads/master
c: 8e1b82e
h: refs/heads/master
v: v3
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Frederic Weisbecker authored and Ingo Molnar committed Dec 8, 2008
1 parent 4c59f80 commit 1fc064c
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Showing 2 changed files with 8 additions and 6 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 8b96f0119818964e4944fd1c423bf6770027d3ac
refs/heads/master: 8e1b82e0866befaa0b2920be296c6e4c3fc7f422
12 changes: 7 additions & 5 deletions trunk/kernel/trace/trace.c
Original file line number Diff line number Diff line change
Expand Up @@ -44,13 +44,14 @@
unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX;
unsigned long __read_mostly tracing_thresh;

/* We need to change this state when a selftest is running.
/*
* We need to change this state when a selftest is running.
* A selftest will lurk into the ring-buffer to count the
* entries inserted during the selftest although some concurrent
* insertions into the ring-buffer such as ftrace_printk could occurred
* at the same time, giving false positive or negative results.
*/
static atomic_t tracing_selftest_running = ATOMIC_INIT(0);
static bool __read_mostly tracing_selftest_running;

/* For tracers that don't implement custom flags */
static struct tracer_opt dummy_tracer_opt[] = {
Expand Down Expand Up @@ -574,6 +575,8 @@ int register_tracer(struct tracer *type)
unlock_kernel();
mutex_lock(&trace_types_lock);

tracing_selftest_running = true;

for (t = trace_types; t; t = t->next) {
if (strcmp(type->name, t->name) == 0) {
/* already found */
Expand All @@ -598,7 +601,6 @@ int register_tracer(struct tracer *type)
struct trace_array *tr = &global_trace;
int i;

atomic_set(&tracing_selftest_running, 1);
/*
* Run a selftest on this tracer.
* Here we reset the trace buffer, and set the current
Expand All @@ -613,7 +615,6 @@ int register_tracer(struct tracer *type)
/* the test is responsible for initializing and enabling */
pr_info("Testing tracer %s: ", type->name);
ret = type->selftest(type, tr);
atomic_set(&tracing_selftest_running, 0);
/* the test is responsible for resetting too */
current_trace = saved_tracer;
if (ret) {
Expand All @@ -635,6 +636,7 @@ int register_tracer(struct tracer *type)
max_tracer_type_len = len;

out:
tracing_selftest_running = false;
mutex_unlock(&trace_types_lock);
lock_kernel();

Expand Down Expand Up @@ -3605,7 +3607,7 @@ int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args)
unsigned long flags, irq_flags;
int cpu, len = 0, size, pc;

if (tracing_disabled || atomic_read(&tracing_selftest_running))
if (tracing_disabled || tracing_selftest_running)
return 0;

pc = preempt_count();
Expand Down

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