Date: Tue, 7 Apr 2026 06:02:35 +0000
From: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Tomas Vondra <tomas@vondra.me>, Andres Freund <andres@anarazel.de>,
	Jeff Davis <pgsql@j-davis.com>,
	Greg Sabino Mullane <htamfids@gmail.com>,
	pgsql-hackers@lists.postgresql.org
Subject: Re: Adding locks statistics
Message-ID: <adSd+4xRpGP2xNiS@ip-10-97-1-34.eu-west-3.compute.internal>
References: <abortN3ngqMcaBJ7@ip-10-97-1-34.eu-west-3.compute.internal>
 <abpfH33mR4Mp9dtO@paquier.xyz>
 <abq71eL7qIdWAxMD@ip-10-97-1-34.eu-west-3.compute.internal>
 <abufUya2oK-_PJ3E@paquier.xyz>
 <abvrRZo52Yx9ZzWQ@ip-10-97-1-34.eu-west-3.compute.internal>
 <ab4y1UQUsSS7bSVd@paquier.xyz>
 <acI3H5aucJNS2w78@paquier.xyz>
 <1af63e6d-16d5-4d5b-9b03-11472ef1adf9@vondra.me>
 <actze31XhGYXNNQg@ip-10-97-1-34.eu-west-3.compute.internal>
 <adNAec0VtP5J4q7m@paquier.xyz>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <adNAec0VtP5J4q7m@paquier.xyz>
Archived-At: 
 <https://www.postgresql.org/message-id/adSd%2B4xRpGP2xNiS%40ip-10-97-1-34.eu-west-3.compute.internal>
Precedence: bulk

Hi,

On Mon, Apr 06, 2026 at 02:11:21PM +0900, Michael Paquier wrote:
> On Tue, Mar 31, 2026 at 07:10:51AM +0000, Bertrand Drouvot wrote:
> > On Mon, Mar 30, 2026 at 06:11:17PM +0200, Tomas Vondra wrote:
> >> Isn't pgstat_lock_flush_cb a bit broken with nowait=true? It'll skip
> >> flushing stats for that particular lock type, but then it'll happily
> >> reset the pending stats anyway, forgetting the stats.
> >> 
> >> AFAIK it should keep the pending stats, and flush them sometime lager,
> >> when the lock is not contended. That's what the other flush callbacks
> >> do, at least. This probably means it needs to reset the entries one by
> >> one, not the whole struct at once.
> > 
> > Oh right, it's currently misbehaving, thanks for the warning!
> 
> I should not have missed that,

So do I...

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com