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authorSteven Rostedt <rostedt@goodmis.org>2008-05-12 21:20:55 +0200
committerThomas Gleixner <tglx@linutronix.de>2008-05-23 21:13:41 +0200
commitc5f888cae49dfe3e86d9d1e0dab2b63ceb057be3 (patch)
treee276b5299b52ccbe8b89492d398fe63652cddd49 /kernel/trace
parent4d9493c90f8e6e1b164aede3814010a290161abb (diff)
downloadlwn-c5f888cae49dfe3e86d9d1e0dab2b63ceb057be3.tar.gz
lwn-c5f888cae49dfe3e86d9d1e0dab2b63ceb057be3.zip
ftrace: irqsoff use raw_smp_processor_id
This patch changes the use of __get_cpu_var to explicitly calling raw_smp_processor_id and using the per_cpu() macro. On some debug configurations, the use of __get_cpu_var may cause ftrace to trigger and this can cause problems with the irqsoff tracing. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/trace_irqsoff.c19
1 files changed, 10 insertions, 9 deletions
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index d0c1748b1e2c..761f3ec66c50 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -204,14 +204,14 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip)
if (likely(!tracer_enabled))
return;
- if (__get_cpu_var(tracing_cpu))
+ cpu = raw_smp_processor_id();
+
+ if (per_cpu(tracing_cpu, cpu))
return;
- cpu = raw_smp_processor_id();
data = tr->data[cpu];
- if (unlikely(!data) || unlikely(!head_page(data)) ||
- atomic_read(&data->disabled))
+ if (unlikely(!data) || atomic_read(&data->disabled))
return;
atomic_inc(&data->disabled);
@@ -225,7 +225,7 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip)
trace_function(tr, data, ip, parent_ip, flags);
- __get_cpu_var(tracing_cpu) = 1;
+ per_cpu(tracing_cpu, cpu) = 1;
atomic_dec(&data->disabled);
}
@@ -238,16 +238,16 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip)
struct trace_array_cpu *data;
unsigned long flags;
+ cpu = raw_smp_processor_id();
/* Always clear the tracing cpu on stopping the trace */
- if (unlikely(__get_cpu_var(tracing_cpu)))
- __get_cpu_var(tracing_cpu) = 0;
+ if (unlikely(per_cpu(tracing_cpu, cpu)))
+ per_cpu(tracing_cpu, cpu) = 0;
else
return;
if (!tracer_enabled)
return;
- cpu = raw_smp_processor_id();
data = tr->data[cpu];
if (unlikely(!data) || unlikely(!head_page(data)) ||
@@ -255,6 +255,7 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip)
return;
atomic_inc(&data->disabled);
+
local_save_flags(flags);
trace_function(tr, data, ip, parent_ip, flags);
check_critical_timing(tr, data, parent_ip ? : ip, cpu);
@@ -376,7 +377,7 @@ static void stop_irqsoff_tracer(struct trace_array *tr)
static void __irqsoff_tracer_init(struct trace_array *tr)
{
irqsoff_trace = tr;
- /* make sure that the tracer is visibel */
+ /* make sure that the tracer is visible */
smp_wmb();
if (tr->ctrl)