mm/page-writeback.c: place "not" inside of unlikely() statement in wb_domain_writeout...

The likely/unlikely profiler noticed that the unlikely statement in
wb_domain_writeout_inc() is constantly wrong.  This is due to the "not"
(!) being outside the unlikely statement.  It is likely that
dom->period_time will be set, but unlikely that it wont be.  Move the
not into the unlikely statement.

Link: http://lkml.kernel.org/r/20170206120035.3c2e2b91@gandalf.local.home
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 2164498258594aff4a72e1263798e1cdec47e3d4..ae6e601f0a58e976d57969c09be4d8185ba8be4c 100644 (file)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -580,7 +580,7 @@ static void wb_domain_writeout_inc(struct wb_domain *dom,
        __fprop_inc_percpu_max(&dom->completions, completions,
                               max_prop_frac);
        /* First event after period switching was turned off? */
-       if (!unlikely(dom->period_time)) {
+       if (unlikely(!dom->period_time)) {
                /*
                 * We can race with other __bdi_writeout_inc calls here but
                 * it does not cause any harm since the resulting time when