[for-next][PATCH 6/8] ring-buffer: Force inline of hotpath helper functions

From: Steven Rostedt
Date: Tue Nov 29 2016 - 10:14:57 EST


From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx>

There's several small helper functions in ring_buffer.c that are used in the
hot path. For some reason, even though they are marked inline, gcc tends not
to enforce it. Make sure these functions are always inlined.

Link: http://lkml.kernel.org/r/20161121183700.GW26852@xxxxxxxxxxxxxxxxxx

Reported-by: Andi Kleen <andi@xxxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
kernel/trace/ring_buffer.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 2760aaca6d1b..04068c0ed927 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1829,48 +1829,48 @@ void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val)
}
EXPORT_SYMBOL_GPL(ring_buffer_change_overwrite);

-static inline void *
+static __always_inline void *
__rb_data_page_index(struct buffer_data_page *bpage, unsigned index)
{
return bpage->data + index;
}

-static inline void *__rb_page_index(struct buffer_page *bpage, unsigned index)
+static __always_inline void *__rb_page_index(struct buffer_page *bpage, unsigned index)
{
return bpage->page->data + index;
}

-static inline struct ring_buffer_event *
+static __always_inline struct ring_buffer_event *
rb_reader_event(struct ring_buffer_per_cpu *cpu_buffer)
{
return __rb_page_index(cpu_buffer->reader_page,
cpu_buffer->reader_page->read);
}

-static inline struct ring_buffer_event *
+static __always_inline struct ring_buffer_event *
rb_iter_head_event(struct ring_buffer_iter *iter)
{
return __rb_page_index(iter->head_page, iter->head);
}

-static inline unsigned rb_page_commit(struct buffer_page *bpage)
+static __always_inline unsigned rb_page_commit(struct buffer_page *bpage)
{
return local_read(&bpage->page->commit);
}

/* Size is determined by what has been committed */
-static inline unsigned rb_page_size(struct buffer_page *bpage)
+static __always_inline unsigned rb_page_size(struct buffer_page *bpage)
{
return rb_page_commit(bpage);
}

-static inline unsigned
+static __always_inline unsigned
rb_commit_index(struct ring_buffer_per_cpu *cpu_buffer)
{
return rb_page_commit(cpu_buffer->commit_page);
}

-static inline unsigned
+static __always_inline unsigned
rb_event_index(struct ring_buffer_event *event)
{
unsigned long addr = (unsigned long)event;
--
2.10.2