| From: | Nathan Bossart <nathandbossart(at)gmail(dot)com> |
|---|---|
| To: | Sami Imseih <samimseih(at)gmail(dot)com> |
| Cc: | Rahila Syed <rahilasyed90(at)gmail(dot)com>, Bertrand Drouvot <bertranddrouvot(dot)pg(at)gmail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Andres Freund <andres(at)anarazel(dot)de>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Improve LWLock tranche name visibility across backends |
| Date: | 2025-09-04 20:37:51 |
| Message-ID: | aLn4n-5UFzKHFdR5@nathan |
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| Lists: | pgsql-hackers |
On Thu, Sep 04, 2025 at 12:30:27PM -0500, Sami Imseih wrote:
> I liked removing the repalloc calls inside this routine and did not think
> it was worth optimizing. I am OK with reverting it back. Although v1
> is incorrect since it's still initializing
> NamedLWLockTrancheRequestArray to MAX_NAMED_TRANCHES
Committed with that fix.
>> Furthermore, the
>> MAX_NAMED_TRANCHES check isn't actually needed because InitializeLWLocks()
>> will do the same check via its calls to LWLockNewTrancheId() for all the
>> named tranche requests.
>
> I thought about that one and decided to add the error message there, since
> requesting a tranche happens way before LWLockNewTrancheId is called
> during CreateLWLocks, so it was more about erroring out slightly earlier.
> But it may be ok to also just remove it.
We needed it before because the array could only ever hold
MAX_NAMED_TRANCHES requests.
--
nathan
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