Re: Show WAL write and fsync stats in pg_stat_io

Michael Paquier <michael@paquier.xyz> writes:
> At the end, we want this patch and this data, and my benchmarcking is
> not showing much differences even if going through a workload with
> many pages, so I've used the version relying entirely on
> track_io_timing and applied it.

Locally, the test added by this commit fails like so:

diff -U3 /home/postgres/pgsql/src/test/regress/expected/stats.out /home/postgres
/pgsql/src/test/regress/results/stats.out
--- /home/postgres/pgsql/src/test/regress/expected/stats.out    2025-02-04 12:33
:07.456393545 -0500
+++ /home/postgres/pgsql/src/test/regress/results/stats.out     2025-02-05 13:08
:30.605638432 -0500
@@ -886,7 +886,7 @@
   WHERE context = 'normal' AND object = 'wal';
  ?column?
 ----------
- t
+ f
 (1 row)

 -----

This is pretty repeatable (not perfectly so) in a build with
--enable-debug --enable-cassert --enable-tap-tests --with-llvm
but it usually passes without --with-llvm.  System is fairly
up-to-date RHEL8 on x86_64.  No idea why the buildfarm isn't
unhappy.  Any pointers where to look?

            regards, tom lane