From: Steven Rostedt (Google) Date: Tue, 27 Sep 2022 23:15:24 +0000 (-0400) Subject: ring-buffer: Have the shortest_full queue be the shortest not longest X-Git-Tag: v6.1-rc1~35^2~26 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=3b19d614b61b93a131f463817e08219c9ce1fee3;p=tomoyo%2Ftomoyo-test1.git ring-buffer: Have the shortest_full queue be the shortest not longest The logic to know when the shortest waiters on the ring buffer should be woken up or not has uses a less than instead of a greater than compare, which causes the shortest_full to actually be the longest. Link: https://lkml.kernel.org/r/20220927231823.718039222@goodmis.org Cc: stable@vger.kernel.org Cc: Ingo Molnar Cc: Andrew Morton Fixes: 2c2b0a78b3739 ("ring-buffer: Add percentage of ring buffer full to wake up reader") Signed-off-by: Steven Rostedt (Google) --- diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 6b145d48dfd1..02db92c9eb1b 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1011,7 +1011,7 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full) nr_pages = cpu_buffer->nr_pages; dirty = ring_buffer_nr_dirty_pages(buffer, cpu); if (!cpu_buffer->shortest_full || - cpu_buffer->shortest_full < full) + cpu_buffer->shortest_full > full) cpu_buffer->shortest_full = full; raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags); if (!pagebusy &&