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authorLinus Torvalds <torvalds@linux-foundation.org>2010-08-06 09:30:52 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-06 09:30:52 -0700
commit4aed2fd8e3181fea7c09ba79cf64e7e3f4413bf9 (patch)
tree1f69733e5daab4915a76a41de0e4d1dc61e12cfb /kernel/trace/ring_buffer.c
parent3a3527b6461b1298cc53ce72f336346739297ac8 (diff)
parentfc9ea5a1e53ee54f681e226d735008e2a6f8f470 (diff)
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (162 commits) tracing/kprobes: unregister_trace_probe needs to be called under mutex perf: expose event__process function perf events: Fix mmap offset determination perf, powerpc: fsl_emb: Restore setting perf_sample_data.period perf, powerpc: Convert the FSL driver to use local64_t perf tools: Don't keep unreferenced maps when unmaps are detected perf session: Invalidate last_match when removing threads from rb_tree perf session: Free the ref_reloc_sym memory at the right place x86,mmiotrace: Add support for tracing STOS instruction perf, sched migration: Librarize task states and event headers helpers perf, sched migration: Librarize the GUI class perf, sched migration: Make the GUI class client agnostic perf, sched migration: Make it vertically scrollable perf, sched migration: Parameterize cpu height and spacing perf, sched migration: Fix key bindings perf, sched migration: Ignore unhandled task states perf, sched migration: Handle ignored migrate out events perf: New migration tool overview tracing: Drop cpparg() macro perf: Use tracepoint_synchronize_unregister() to flush any pending tracepoint call ... Fix up trivial conflicts in Makefile and drivers/cpufreq/cpufreq.c
Diffstat (limited to 'kernel/trace/ring_buffer.c')
-rw-r--r--kernel/trace/ring_buffer.c40
1 files changed, 9 insertions, 31 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 1da7b6ea8b8..3632ce87674 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -443,6 +443,7 @@ int ring_buffer_print_page_header(struct trace_seq *s)
*/
struct ring_buffer_per_cpu {
int cpu;
+ atomic_t record_disabled;
struct ring_buffer *buffer;
spinlock_t reader_lock; /* serialize readers */
arch_spinlock_t lock;
@@ -462,7 +463,6 @@ struct ring_buffer_per_cpu {
unsigned long read;
u64 write_stamp;
u64 read_stamp;
- atomic_t record_disabled;
};
struct ring_buffer {
@@ -2242,8 +2242,6 @@ static void trace_recursive_unlock(void)
#endif
-static DEFINE_PER_CPU(int, rb_need_resched);
-
/**
* ring_buffer_lock_reserve - reserve a part of the buffer
* @buffer: the ring buffer to reserve from
@@ -2264,13 +2262,13 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer, unsigned long length)
{
struct ring_buffer_per_cpu *cpu_buffer;
struct ring_buffer_event *event;
- int cpu, resched;
+ int cpu;
if (ring_buffer_flags != RB_BUFFERS_ON)
return NULL;
/* If we are tracing schedule, we don't want to recurse */
- resched = ftrace_preempt_disable();
+ preempt_disable_notrace();
if (atomic_read(&buffer->record_disabled))
goto out_nocheck;
@@ -2295,21 +2293,13 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer, unsigned long length)
if (!event)
goto out;
- /*
- * Need to store resched state on this cpu.
- * Only the first needs to.
- */
-
- if (preempt_count() == 1)
- per_cpu(rb_need_resched, cpu) = resched;
-
return event;
out:
trace_recursive_unlock();
out_nocheck:
- ftrace_preempt_enable(resched);
+ preempt_enable_notrace();
return NULL;
}
EXPORT_SYMBOL_GPL(ring_buffer_lock_reserve);
@@ -2355,13 +2345,7 @@ int ring_buffer_unlock_commit(struct ring_buffer *buffer,
trace_recursive_unlock();
- /*
- * Only the last preempt count needs to restore preemption.
- */
- if (preempt_count() == 1)
- ftrace_preempt_enable(per_cpu(rb_need_resched, cpu));
- else
- preempt_enable_no_resched_notrace();
+ preempt_enable_notrace();
return 0;
}
@@ -2469,13 +2453,7 @@ void ring_buffer_discard_commit(struct ring_buffer *buffer,
trace_recursive_unlock();
- /*
- * Only the last preempt count needs to restore preemption.
- */
- if (preempt_count() == 1)
- ftrace_preempt_enable(per_cpu(rb_need_resched, cpu));
- else
- preempt_enable_no_resched_notrace();
+ preempt_enable_notrace();
}
EXPORT_SYMBOL_GPL(ring_buffer_discard_commit);
@@ -2501,12 +2479,12 @@ int ring_buffer_write(struct ring_buffer *buffer,
struct ring_buffer_event *event;
void *body;
int ret = -EBUSY;
- int cpu, resched;
+ int cpu;
if (ring_buffer_flags != RB_BUFFERS_ON)
return -EBUSY;
- resched = ftrace_preempt_disable();
+ preempt_disable_notrace();
if (atomic_read(&buffer->record_disabled))
goto out;
@@ -2536,7 +2514,7 @@ int ring_buffer_write(struct ring_buffer *buffer,
ret = 0;
out:
- ftrace_preempt_enable(resched);
+ preempt_enable_notrace();
return ret;
}