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 446A74628F;
	Fri, 21 Feb 2025 18:16:20 +0100 (CET)
Received: from mails.dpdk.org (localhost [127.0.0.1])
	by mails.dpdk.org (Postfix) with ESMTP id 1211D402CC;
	Fri, 21 Feb 2025 18:16:20 +0100 (CET)
Received: from dkmailrelay1.smartsharesystems.com
 (smartserver.smartsharesystems.com [77.243.40.215])
 by mails.dpdk.org (Postfix) with ESMTP id CF246402BB
 for <dev@dpdk.org>; Fri, 21 Feb 2025 18:16:18 +0100 (CET)
Received: from smartserver.smartsharesystems.com
 (smartserver.smartsharesys.local [192.168.4.10])
 by dkmailrelay1.smartsharesystems.com (Postfix) with ESMTP id AC7EF206C7;
 Fri, 21 Feb 2025 18:16:18 +0100 (CET)
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: Intel FAST_FREE offload question
Date: Fri, 21 Feb 2025 18:16:17 +0100
X-MimeOLE: Produced By Microsoft Exchange V6.5
Message-ID: <98CBD80474FA8B44BF855DF32C47DC35E9FA64@smartserver.smartshare.dk>
In-Reply-To: <Z7izW7ckMhzb1jL6@bricha3-mobl1.ger.corp.intel.com>
X-MS-Has-Attach: 
X-MS-TNEF-Correlator: 
Thread-Topic: Intel FAST_FREE offload question
Thread-Index: AduEg4eycaxpH524RmuMcdlBdDMrcgAAFjfg
References: <98CBD80474FA8B44BF855DF32C47DC35E9FA63@smartserver.smartshare.dk>
 <Z7izW7ckMhzb1jL6@bricha3-mobl1.ger.corp.intel.com>
From: =?iso-8859-1?Q?Morten_Br=F8rup?= <mb@smartsharesystems.com>
To: "Bruce Richardson" <bruce.richardson@intel.com>
Cc: "Anatoly Burakov" <anatoly.burakov@intel.com>,
 "Vladimir Medvedkin" <vladimir.medvedkin@intel.com>,
 "Ian Stokes" <ian.stokes@intel.com>, "Jingjing Wu" <jingjing.wu@intel.com>,
 "Praveen Shetty" <praveen.shetty@intel.com>, <dev@dpdk.org>
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: Bruce Richardson [mailto:bruce.richardson@intel.com]
> Sent: Friday, 21 February 2025 18.10
>=20
> On Fri, Feb 21, 2025 at 05:58:21PM +0100, Morten Br=F8rup wrote:
> > Intel NIC folks,
> >
> > Why do the Intel network drivers, when using
> > RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE, fall back to normal freeing when
> the
> > mempool cache is empty (cache->len =3D=3D 0)? It doesn't make sense =
to
> me.
> >
> > Example:
> > https://git.dpdk.org/dpdk/tree/drivers/net/intel/common/tx.h#n146
> >
> Good question. I suspect that it may be a bug and that we meant to
> check
> for size =3D=3D 0 rather than len =3D=3D 0.

Then checking for cache =3D=3D NULL suffices, because =
rte_mempool_default_cache() returns NULL if the cache size is 0:
https://elixir.bootlin.com/dpdk/v24.11.1/source/lib/mempool/rte_mempool.h=
#L1333