From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <dev-bounces@dpdk.org>
Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124])
	by inbox.dpdk.org (Postfix) with ESMTP id 259F1440B6;
	Fri, 24 May 2024 14:20:18 +0200 (CEST)
Received: from mails.dpdk.org (localhost [127.0.0.1])
	by mails.dpdk.org (Postfix) with ESMTP id E67BD402BF;
	Fri, 24 May 2024 14:20:17 +0200 (CEST)
Received: from dkmailrelay1.smartsharesystems.com
 (smartserver.smartsharesystems.com [77.243.40.215])
 by mails.dpdk.org (Postfix) with ESMTP id 8A45240271
 for <dev@dpdk.org>; Fri, 24 May 2024 14:20:16 +0200 (CEST)
Received: from smartserver.smartsharesystems.com
 (smartserver.smartsharesys.local [192.168.4.10])
 by dkmailrelay1.smartsharesystems.com (Postfix) with ESMTP id 6126F2035F;
 Fri, 24 May 2024 14:20:16 +0200 (CEST)
Content-class: urn:content-classes:message
MIME-Version: 1.0
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Subject: RE: [PATCH v11 2/6] mempool: add functions to get extra mempool info
X-MimeOLE: Produced By Microsoft Exchange V6.5
Date: Fri, 24 May 2024 14:20:14 +0200
Message-ID: <98CBD80474FA8B44BF855DF32C47DC35E9F495@smartserver.smartshare.dk>
In-Reply-To: <20240524083651.482541-3-paul.szczepanek@arm.com>
X-MS-Has-Attach: 
X-MS-TNEF-Correlator: 
Thread-Topic: [PATCH v11 2/6] mempool: add functions to get extra mempool info
Thread-Index: AdqttZNkeWx2+eQbQ0Sos/ec8v37fAAHGFPQ
References: <20230927150854.3670391-2-paul.szczepanek@arm.com>
 <20240524083651.482541-1-paul.szczepanek@arm.com>
 <20240524083651.482541-3-paul.szczepanek@arm.com>
From: =?iso-8859-1?Q?Morten_Br=F8rup?= <mb@smartsharesystems.com>
To: "Paul Szczepanek" <paul.szczepanek@arm.com>,
	<dev@dpdk.org>
Cc: "Jack Bond-Preston" <jack.bond-preston@arm.com>,
 "Yoan Picchi" <yoan.picchi@arm.com>, "Nathan Brown" <nathan.brown@arm.com>
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org

> From: Paul Szczepanek [mailto:paul.szczepanek@arm.com]
> Sent: Friday, 24 May 2024 10.37
>=20
> +size_t rte_mempool_get_obj_alignment(struct rte_mempool *mp)
> +{
> +	if (mp =3D=3D NULL)
> +		return 0;
> +
> +	if (mp->flags & RTE_MEMPOOL_F_NO_CACHE_ALIGN)
> +		return sizeof(uint64_t);
> +	else
> +		return RTE_MEMPOOL_ALIGN;
> +}

The object alignment depends on the underlying mempool driver. You =
cannot assume that it is either sizeof(uint64_t) or cache line aligned.

Refer to the calc_mem_size driver operation, which also provides object =
alignment information:
https://elixir.bootlin.com/dpdk/v24.03/source/lib/mempool/rte_mempool.h#L=
529

If you need this function, you need to add a new driver operation, and =
your function above can be the default for this operation, like for the =
the calc_mem_size driver operation:
https://elixir.bootlin.com/dpdk/v24.03/source/lib/mempool/rte_mempool_ops=
.c#L120