Thread

Re: GNU/Hurd portability patches

Alexander Lakhin <exclusion@gmail.com> — 2025-09-24T20:00:00Z

24.09.2025 18:52, Michael Banck wrote:
> On Wed, Sep 24, 2025 at 10:28:46AM -0400, Tom Lane wrote:
>> It seems plausible that the execution time of the stats
>> test's function-under-test is so short that it sometimes
>> doesn't register as more than zero on a machine with poor
>> clock resolution.  It looks like that test only calls the
>> test function once or twice before checking that it's
>> accumulated some runtime, and the test function is nothing
>> more than
>>
>>      CREATE FUNCTION test_stat_func() RETURNS VOID LANGUAGE plpgsql AS $$BEGIN END;$$;
>>
>> I'd call this a bug in that test TBH.  It'd be saner to
>> make the function do something like pg_sleep for 1ms.
> I did that in the attached, so far my Hurd VM ran the stats test more
> than 1000 times without a failure with it. I have the loop running till
> 10000, I'll report back tomorrow.

If the stats test could be fixed this way, I wonder how to deal with
regress/subscription.sql. When running:
TESTS="$(printf "subscription %.0s" `seq 1000`)" make -s check-tests

on the same Hurd VM, I'm observing:
...
ok 986       - subscription                               53 ms
not ok 987   - subscription                               53 ms
ok 988       - subscription                               53 ms
...
# 4 of 1000 tests failed.
# The differences that caused some tests to fail can be viewed in the file 
"/home/demo/postgresql/src/test/regress/regression.diffs".

$ cat "/home/demo/postgresql/src/test/regress/regression.diffs"

--- /home/demo/postgresql/src/test/regress/expected/subscription.out 2025-09-24 19:49:53.000000000 +0100
+++ /home/demo/postgresql/src/test/regress/results/subscription.out 2025-09-24 20:06:48.000000000 +0100
@@ -70,7 +70,7 @@
  SELECT :'prev_stats_reset' < stats_reset FROM pg_stat_subscription_stats WHERE subname = 'regress_testsub';
   ?column?
  ----------
- t
+ f
  (1 row)

  -- fail - name already exists
diff -U3 /home/demo/postgresql/src/test/regress/expected/subscription.out 
/home/demo/postgresql/src/test/regress/results/subscription.out
--- /home/demo/postgresql/src/test/regress/expected/subscription.out 2025-09-24 19:49:53.000000000 +0100
+++ /home/demo/postgresql/src/test/regress/results/subscription.out 2025-09-24 20:07:13.000000000 +0100
@@ -70,7 +70,7 @@
  SELECT :'prev_stats_reset' < stats_reset FROM pg_stat_subscription_stats WHERE subname = 'regress_testsub';
   ?column?
  ----------
- t
+ f
  (1 row)

  -- fail - name already exists
diff -U3 /home/demo/postgresql/src/test/regress/expected/subscription.out 
/home/demo/postgresql/src/test/regress/results/subscription.out
--- /home/demo/postgresql/src/test/regress/expected/subscription.out 2025-09-24 19:49:53.000000000 +0100
+++ /home/demo/postgresql/src/test/regress/results/subscription.out 2025-09-24 20:07:28.000000000 +0100
@@ -70,7 +70,7 @@
  SELECT :'prev_stats_reset' < stats_reset FROM pg_stat_subscription_stats WHERE subname = 'regress_testsub';
   ?column?
  ----------
- t
+ f
  (1 row)

  -- fail - name already exists
diff -U3 /home/demo/postgresql/src/test/regress/expected/subscription.out 
/home/demo/postgresql/src/test/regress/results/subscription.out
--- /home/demo/postgresql/src/test/regress/expected/subscription.out 2025-09-24 19:49:53.000000000 +0100
+++ /home/demo/postgresql/src/test/regress/results/subscription.out 2025-09-24 20:07:33.000000000 +0100
@@ -70,7 +70,7 @@
  SELECT :'prev_stats_reset' < stats_reset FROM pg_stat_subscription_stats WHERE subname = 'regress_testsub';
   ?column?
  ----------
- t
+ f
  (1 row)

  -- fail - name already exists


Best regards,
Alexander