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authorJames Morris <james.morris@microsoft.com>2018-09-04 11:35:54 -0700
committerJames Morris <james.morris@microsoft.com>2018-09-04 11:35:54 -0700
commite42f6f9be4f83c537aa81b4c6239ea94ff5b29ce (patch)
treef956a5ea0e83fc6d0df3e64681e7bbc1f201f3ee /kernel/trace/ring_buffer.c
parent4408e300a67ab2ce2505087986a9fe922c800ffd (diff)
parent57361846b52bc686112da6ca5368d11210796804 (diff)
Merge tag 'v4.19-rc2' into next-general
Sync to Linux 4.19-rc2 for downstream developers.
Diffstat (limited to 'kernel/trace/ring_buffer.c')
-rw-r--r--kernel/trace/ring_buffer.c19
1 files changed, 18 insertions, 1 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 6a46af21765c..1d92d4a982fd 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* Generic ring buffer
*
@@ -3221,12 +3222,28 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_on);
*
* Returns true if the ring buffer is in a state that it accepts writes.
*/
-int ring_buffer_record_is_on(struct ring_buffer *buffer)
+bool ring_buffer_record_is_on(struct ring_buffer *buffer)
{
return !atomic_read(&buffer->record_disabled);
}
/**
+ * ring_buffer_record_is_set_on - return true if the ring buffer is set writable
+ * @buffer: The ring buffer to see if write is set enabled
+ *
+ * Returns true if the ring buffer is set writable by ring_buffer_record_on().
+ * Note that this does NOT mean it is in a writable state.
+ *
+ * It may return true when the ring buffer has been disabled by
+ * ring_buffer_record_disable(), as that is a temporary disabling of
+ * the ring buffer.
+ */
+bool ring_buffer_record_is_set_on(struct ring_buffer *buffer)
+{
+ return !(atomic_read(&buffer->record_disabled) & RB_BUFFER_OFF);
+}
+
+/**
* ring_buffer_record_disable_cpu - stop all writes into the cpu_buffer
* @buffer: The ring buffer to stop writes to.
* @cpu: The CPU buffer to stop