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authorNeilBrown <neilb@suse.de>2012-08-01 20:40:02 +1000
committerNeilBrown <neilb@suse.de>2012-08-01 20:40:02 +1000
commitbb181e2e48f8c85db08c9cb015cbba9618dbf05c (patch)
tree191bc24dd97bcb174535cc217af082f16da3b43d /kernel/trace/ring_buffer.c
parentd57368afe63b3b7b45ce6c2b8c5276417935be2f (diff)
parentc039c332f23e794deb6d6f37b9f07ff3b27fb2cf (diff)
downloadtalos-op-linux-bb181e2e48f8c85db08c9cb015cbba9618dbf05c.tar.gz
talos-op-linux-bb181e2e48f8c85db08c9cb015cbba9618dbf05c.zip
Merge commit 'c039c332f23e794deb6d6f37b9f07ff3b27fb2cf' into md
Pull in pre-requisites for adding raid10 support to dm-raid.
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 f765465bffe4..49491fa7daa2 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.
*/
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