From: Ryoga Yoshida <bt23yoshidar@oss.nttdata.com>
To: pgsql-hackers@lists.postgresql.org
Subject: Doesn't pgstat_report_wal() handle the argument "force" incorrectly
Date: Fri, 22 Sep 2023 13:58:37 +0900
Message-ID: <f87a4d7be70530606b864fd1df91718c@oss.nttdata.com> (raw)
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 Yoshida
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To: pgsql-hackers@postgresql.org
Cc: bt23yoshidar@oss.nttdata.com, pgsql-hackers@lists.postgresql.org
Subject: Re: Doesn't pgstat_report_wal() handle the argument "force" incorrectly
In-Reply-To: <f87a4d7be70530606b864fd1df91718c@oss.nttdata.com>
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