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authorIngo Molnar <mingo@kernel.org>2012-07-06 11:12:17 +0200
committerIngo Molnar <mingo@kernel.org>2012-07-06 11:12:17 +0200
commit35c2f48c66d9c1b8d794c3936c3be22aa7c89adb (patch)
treede0233d45fec273920bce0bc8640465cbf439600 /kernel/trace/ring_buffer.c
parent47fbc518a4b5c9a949f7cab8b14a00d3549bf138 (diff)
parenta5fb833172eca69136e9ee1ada778e404086ab8a (diff)
downloadlinux-35c2f48c66d9c1b8d794c3936c3be22aa7c89adb.tar.bz2
Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core
Pull tracing updates from Steve Rostedt. Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/trace/ring_buffer.c')
-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 1d0f6a8a0e5e..82a3e0c56b1d 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -3239,6 +3239,10 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
if (cpu_buffer->commit_page == cpu_buffer->reader_page)
goto out;
+ /* Don't bother swapping if the ring buffer is empty */
+ if (rb_num_of_entries(cpu_buffer) == 0)
+ goto out;
+
/*
* Reset the reader page to size zero.
*/