Instead of open-coding the equivalent cmpxchg loop we can just use
atomic_set_mask and atomic_clear_mask to atomically OR or AND
the value in &buffer->record_disabled.
Cc: Steven Rostedt <rost...@goodmis.org>
Cc: Ingo Molnar <mi...@redhat.com>
Signed-off-by: Patrick Palka <patr...@parcs.ath.cx>
---
NB: I have only tested this patch on x86_64 by booting with
CONFIG_RING_BUFFER_STARTUP_TEST=y.
kernel/trace/ring_buffer.c | 16 ++--------------
1 file changed, 2 insertions(+), 14 deletions(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 2d75c94..e15ce2a 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -3050,13 +3050,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_enable);
*/
void ring_buffer_record_off(struct ring_buffer *buffer)
{
- unsigned int rd;
- unsigned int new_rd;
-
- do {
- rd = atomic_read(&buffer->record_disabled);
- new_rd = rd | RB_BUFFER_OFF;
- } while (atomic_cmpxchg(&buffer->record_disabled, rd, new_rd) != rd);
+ atomic_set_mask(RB_BUFFER_OFF, &buffer->record_disabled);
}
EXPORT_SYMBOL_GPL(ring_buffer_record_off);
@@ -3073,13 +3067,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_off);
*/
void ring_buffer_record_on(struct ring_buffer *buffer)
{
- unsigned int rd;
- unsigned int new_rd;
-
- do {
- rd = atomic_read(&buffer->record_disabled);
- new_rd = rd & ~RB_BUFFER_OFF;
- } while (atomic_cmpxchg(&buffer->record_disabled, rd, new_rd) != rd);
+ atomic_clear_mask(RB_BUFFER_OFF, &buffer->record_disabled);
}
EXPORT_SYMBOL_GPL(ring_buffer_record_on);
--
2.1.2.443.g670a3c1
--
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