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this_cpu: Use this_cpu_xx for ftrace

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this_cpu_xx can reduce the instruction count here and also
avoid address arithmetic.

Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Christoph Lameter 2009-10-07 19:17:45 -04:00 committed by Tejun Heo
parent 494f6a9e12
commit 9288f99aa5
2 changed files with 5 additions and 5 deletions
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8
kernel/trace/trace.c
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@ -86,17 +86,17 @@ static int dummy_set_flag(u32 old_flags, u32 bit, int set)
*/
static int tracing_disabled = 1;
DEFINE_PER_CPU(local_t, ftrace_cpu_disabled);
DEFINE_PER_CPU(int, ftrace_cpu_disabled);
static inline void ftrace_disable_cpu(void)
{
preempt_disable();
local_inc(&__get_cpu_var(ftrace_cpu_disabled));
__this_cpu_inc(per_cpu_var(ftrace_cpu_disabled));
}
static inline void ftrace_enable_cpu(void)
{
local_dec(&__get_cpu_var(ftrace_cpu_disabled));
__this_cpu_dec(per_cpu_var(ftrace_cpu_disabled));
preempt_enable();
}
@ -1085,7 +1085,7 @@ trace_function(struct trace_array *tr,
struct ftrace_entry *entry;
/* If we are reading the ring buffer, don't trace */
if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
if (unlikely(__this_cpu_read(per_cpu_var(ftrace_cpu_disabled))))
return;
event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry),

2
kernel/trace/trace.h
View File

@ -413,7 +413,7 @@ extern int DYN_FTRACE_TEST_NAME(void);
extern int ring_buffer_expanded;
extern bool tracing_selftest_disabled;
DECLARE_PER_CPU(local_t, ftrace_cpu_disabled);
DECLARE_PER_CPU(int, ftrace_cpu_disabled);
#ifdef CONFIG_FTRACE_STARTUP_TEST
extern int trace_selftest_startup_function(struct tracer *trace,