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authorSteven Rostedt <srostedt@redhat.com>2009-05-02 00:26:54 (GMT)
committerSteven Rostedt <rostedt@goodmis.org>2009-05-05 21:22:02 (GMT)
commit41ede23eded40832c955d98d4b71bc244809abb3 (patch)
tree044d968ac2d5784a80b46ba2ea04e639ac3e501b
parentafbab76a62b69ea6197e19727d4b8a8aef8deb25 (diff)
downloadlinux-41ede23eded40832c955d98d4b71bc244809abb3.tar.xz
ring-buffer: disable writers when resetting buffers
As a precaution, it is best to disable writing to the ring buffers when reseting them. [ Impact: prevent weird things if write happens during reset ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--kernel/trace/ring_buffer.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 9e42a74..7876df0 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2650,6 +2650,8 @@ void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu)
if (!cpumask_test_cpu(cpu, buffer->cpumask))
return;
+ atomic_inc(&cpu_buffer->record_disabled);
+
spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
__raw_spin_lock(&cpu_buffer->lock);
@@ -2659,6 +2661,8 @@ void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu)
__raw_spin_unlock(&cpu_buffer->lock);
spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
+
+ atomic_dec(&cpu_buffer->record_disabled);
}
EXPORT_SYMBOL_GPL(ring_buffer_reset_cpu);