Messages in this thread Patch in this message | | | Date | Thu, 02 Jul 2020 17:58:26 -0400 | From | Steven Rostedt <> | Subject | [for-next][PATCH 14/18] ring-buffer: Mark the !tail (crossing a page) as unlikely |
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From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
It is the uncommon case where an event crosses a sub buffer boundary (page) mark that check at the end of reserving an event as unlikely.
Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> --- kernel/trace/ring_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index ed1941304f69..888bc9177937 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3260,7 +3260,7 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer, * If this is the first commit on the page, then update * its timestamp. */ - if (!tail) + if (unlikely(!tail)) tail_page->page->time_stamp = info->ts; /* account for these added bytes */ -- 2.26.2
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