Re: PGPROC alignment (was Re: pgsql: Separate RecoveryConflictReasons from procsignals) - Mailing list pgsql-hackers

Hi,

On Wed, Feb 11, 2026 at 12:03:51PM +0200, Heikki Linnakangas wrote:
> On 11/02/2026 06:40, Bertrand Drouvot wrote:
> > > With this, sizeof(PGPROC) == 864 without the explicit alignment to
> > > PG_CACHE_LINE_SIZE, and 896 with it.
> > 
> > I can see 876 -> 896 on my side:
> > 
> > /*    872      |       4 */    uint32 wait_event_info;
> > /* XXX 20-byte padding   */
> > 
> >                                 /* total size (bytes):  896 */
> >                               }
> 
> Interesting. I've attached 'pahole bin/postgres' output from my laptop. It's
> Linux on arm64.

Thanks!

Got it: I was using "-DCACHEDEBUG -DWAL_DEBUG -DLOCK_DEBUG -DDEBUG_DEADLOCK"
so that with LOCK_DEBUG in place then LWLock size is 32 bytes (vs 16 in your case).

Regards,

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