Doesn't pgstat_report_wal() handle the argument "force" incorrectly

[Ryoga Yoshida]

Hi,

pgstat_report_wal() calls pgstat_flush_wal() and pgstat_flush_io(). When 
calling them, pgstat_report_wal() specifies its argument "force" as the 
argument of them, as follows. But according to the code of 
pgstat_flush_wal() and pgstat_flush_io(), their argument is "nowait" and 
its meaning seems the opposite of "force". This means that, even when 
checkpointer etc calls pgstat_report_wal() with force=true to forcibly 
flush the statistics, pgstat_flush_wal() and pgstat_flush_io() skip 
flushing the statistics if they fail to acquire the lock immediately 
because they are called with nowait=true. This seems unexpected behavior 
and a bug.
void
pgstat_report_wal(bool force)
{
    pgstat_flush_wal(force);
    pgstat_flush_io(force);
}

BTW, pgstat_report_stat() treats "nowait" and "force" as the opposite 
one, as follows.
/* don't wait for lock acquisition when !force */
nowait = !force;

Ryoga Yoshidadiff --git a/src/backend/utils/activity/pgstat_wal.c b/src/backend/utils/activity/pgstat_wal.c
index bcaed14d02..f9b5ee8a7b 100644
--- a/src/backend/utils/activity/pgstat_wal.c
+++ b/src/backend/utils/activity/pgstat_wal.c
@@ -42,9 +42,9 @@ static WalUsage prevWalUsage;
 void
 pgstat_report_wal(bool force)
 {
-	pgstat_flush_wal(force);
+	pgstat_flush_wal(!force);
 
-	pgstat_flush_io(force);
+	pgstat_flush_io(!force);
 }
 
 /*