Re: Remove useless pointer advance in StatsShmemInit() - Mailing list pgsql-hackers

From Bertrand Drouvot
Subject Re: Remove useless pointer advance in StatsShmemInit()
Date
Msg-id aKLy4khK3xcGr3q9@ip-10-97-1-34.eu-west-3.compute.internal
Whole thread Raw
In response to Re: Remove useless pointer advance in StatsShmemInit()  (Michael Paquier <michael@paquier.xyz>)
List pgsql-hackers
Hi,

On Mon, Aug 18, 2025 at 06:13:05PM +0900, Michael Paquier wrote:
> On Mon, Aug 18, 2025 at 09:04:59AM +0000, Bertrand Drouvot wrote:
> > As StatsShmemInit() is existing code, let's fix it: the pointer is not used after
> > its last advance, so that advance is unnecessary and can be removed.
> > @@ -180,7 +180,6 @@ StatsShmemInit(void)
> 
>           * provides a small efficiency win.
>           */
>          ctl->raw_dsa_area = p;
> -        p += MAXALIGN(pgstat_dsa_init_size());
>          dsa = dsa_create_in_place(ctl->raw_dsa_area,
>                                    pgstat_dsa_init_size(),
>                                    LWTRANCHE_PGSTATS_DSA, NULL);
> 
> One could argue that "p" could be removed, moving the
> sizeof(PgStat_ShmemControl) when we set raw_dsa_area, but that's a bit
> cleaner with the extra pointer assignment and the comment for
> pgStatLocal.shmem. 

Yeah, that's probably just a matter of taste, but I also prefer keeping the
pointer over just doing:

ctl->raw_dsa_area = (char *) ctl + MAXALIGN(sizeof(PgStat_ShmemControl));

Regards,

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



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