Re: False "pg_serial": apparent wraparound” in logs

On Mon, Oct 16, 2023 at 04:58:31PM +0900, Michael Paquier wrote:
> On Sat, Oct 14, 2023 at 07:29:54PM +0000, Imseih (AWS), Sami wrote:
>> After looking at this a bit more, I don't think the previous rev is correct.
>> We should not fall through to the " The SLRU is no longer needed." Which
>> also sets the headPage to invalid. We should only truncate up to the
>> head page.
>
> Seems correct to me. Or this would count as if the SLRU is not in
> use, but it's being used.

So, I've spent more time on that and applied the simplification today,
doing as you have suggested to use the head page rather than the tail
page when the tail XID is ahead of the head XID, but without disabling
the whole. I've simplified a bit the code and the comments, though,
while on it (some renames and a slight refactoring of tailPage, for
example).
--
Michael