Re: Draft for basic NUMA observability

From: Jakub Wartak <jakub(dot)wartak(at)enterprisedb(dot)com>
To: Bertrand Drouvot <bertranddrouvot(dot)pg(at)gmail(dot)com>
Cc: Andres Freund <andres(at)anarazel(dot)de>, Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>, Nazir Bilal Yavuz <byavuz81(at)gmail(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Draft for basic NUMA observability
Date: 2025-04-03 06:56:41
Message-ID: CAKZiRmyQCpLSN=TqtR7i_Xc-D-UsV4YAGQznuMtdMfQSW2QDNg@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On Wed, Apr 2, 2025 at 5:27 PM Bertrand Drouvot
<bertranddrouvot(dot)pg(at)gmail(dot)com> wrote:
>
> Hi Jakub,

Hi Bertrand,

> > OK, but I still fail to grasp why pg_indent doesnt fix this stuff on
> > it's own... I believe orginal ident, would fix this on it's own?
>
> My comment was not about indention but about the fact that I think that the
> casting is not a the right place. I think that's the result of the multiplication
> that we want to be casted (cast operator has higher precedence than Multiplication
> operator).

Oh! I've missed that, but v21 got a rewrite (still not polished) just
to show it can be done without float points as Tomas requested.

[..]
> Ok, but then does it make sense to see some num_size < shmem_size?
>
> postgres=# select c.name, c.size as num_size, s.size as shmem_size
> from (select n.name as name, sum(n.size) as size from pg_shmem_numa_allocations n group by n.name) c, pg_shmem_allocations s
> where c.name = s.name and s.size > c.size;
> name | num_size | shmem_size
> ---------------+-----------+------------
> XLOG Ctl | 4194304 | 4208200
> Buffer Blocks | 134217728 | 134221824
> AioHandleIOV | 2097152 | 2850816

This was a real bug, fixed in v21 , the ent->allocated_size was not
properly page aligned. Thanks for the attention to detail.

-J.

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Hayato Kuroda (Fujitsu) 2025-04-03 06:57:00 RE: pg_recvlogical cannot create slots with failover=true
Previous Message Ashutosh Bapat 2025-04-03 06:38:14 Re: Test to dump and restore objects left behind by regression