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authorVaibhav Nagarnaik <vnagarnaik@google.com>2012-02-02 12:00:41 -0800
committerSteven Rostedt <rostedt@goodmis.org>2012-04-23 21:17:51 -0400
commit438ced1720b584000a9e8a4349d1f6bb7ee3ad6d (patch)
tree2c769e58411c68b298ab816c577ecb2119c7067c /include/linux/ring_buffer.h
parent5a26c8f0cf1e95106858bb4e23ca6dd14c9b842f (diff)
ring-buffer: Add per_cpu ring buffer control files
Add a debugfs entry under per_cpu/ folder for each cpu called buffer_size_kb to control the ring buffer size for each CPU independently. If the global file buffer_size_kb is used to set size, the individual ring buffers will be adjusted to the given size. The buffer_size_kb will report the common size to maintain backward compatibility. If the buffer_size_kb file under the per_cpu/ directory is used to change buffer size for a specific CPU, only the size of the respective ring buffer is updated. When tracing/buffer_size_kb is read, it reports 'X' to indicate that sizes of per_cpu ring buffers are not equivalent. Link: http://lkml.kernel.org/r/1328212844-11889-1-git-send-email-vnagarnaik@google.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Michael Rubin <mrubin@google.com> Cc: David Sharp <dhsharp@google.com> Cc: Justin Teravest <teravest@google.com> Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'include/linux/ring_buffer.h')
-rw-r--r--include/linux/ring_buffer.h6
1 files changed, 4 insertions, 2 deletions
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index 7be2e88f23fd..6c8835f74f79 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -96,9 +96,11 @@ __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *k
__ring_buffer_alloc((size), (flags), &__key); \
})
+#define RING_BUFFER_ALL_CPUS -1
+
void ring_buffer_free(struct ring_buffer *buffer);
-int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size);
+int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size, int cpu);
void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val);
@@ -129,7 +131,7 @@ ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts);
void ring_buffer_iter_reset(struct ring_buffer_iter *iter);
int ring_buffer_iter_empty(struct ring_buffer_iter *iter);
-unsigned long ring_buffer_size(struct ring_buffer *buffer);
+unsigned long ring_buffer_size(struct ring_buffer *buffer, int cpu);
void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu);
void ring_buffer_reset(struct ring_buffer *buffer);