From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 6F8C447049; Mon, 15 Dec 2025 19:53:30 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id AEEBC4029A; Mon, 15 Dec 2025 19:53:29 +0100 (CET) Received: from dkmailrelay1.smartsharesystems.com (smartserver.smartsharesystems.com [77.243.40.215]) by mails.dpdk.org (Postfix) with ESMTP id 0488E40151 for ; Mon, 15 Dec 2025 19:53:27 +0100 (CET) Received: from smartserver.smartsharesystems.com (smartserver.smartsharesys.local [192.168.4.10]) by dkmailrelay1.smartsharesystems.com (Postfix) with ESMTP id D77D1202E1; Mon, 15 Dec 2025 19:53:27 +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: [PATCH] net/intel: improve Rx descriptor ring size checks Date: Mon, 15 Dec 2025 19:53:27 +0100 Message-ID: <98CBD80474FA8B44BF855DF32C47DC35F655E7@smartserver.smartshare.dk> X-MimeOLE: Produced By Microsoft Exchange V6.5 In-Reply-To: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [PATCH] net/intel: improve Rx descriptor ring size checks Thread-Index: Adxt741lhnho/bI2SoeKYhdVhRDkmgAAvMVw References: <20251215173543.1707960-1-bruce.richardson@intel.com> <98CBD80474FA8B44BF855DF32C47DC35F655E6@smartserver.smartshare.dk> From: =?iso-8859-1?Q?Morten_Br=F8rup?= To: "Bruce Richardson" Cc: , "Praveen Shetty" , "Vladimir Medvedkin" , "Anatoly Burakov" , "Jingjing Wu" X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org > From: Bruce Richardson [mailto:bruce.richardson@intel.com] > Sent: Monday, 15 December 2025 19.21 >=20 > On Mon, Dec 15, 2025 at 05:58:33PM +0000, Bruce Richardson wrote: > > On Mon, Dec 15, 2025 at 06:54:50PM +0100, Morten Br=F8rup wrote: > > > > From: Bruce Richardson [mailto:bruce.richardson@intel.com] > > > > Sent: Monday, 15 December 2025 18.36 > > > > > > > > The default Rx ring size checks did not account for the fact = that > the > > > > port would not work correctly if the Rx ring size was only twice > the > > > > free threshold size or less, so add in a new check for this. = This > would > > > > generally only apply in cases where very small rings sizes are > being > > > > used, for example, with default Rx free thresh of 32, only ring > size of > > > > 64 would cause issues. > > > > > > > > Signed-off-by: Bruce Richardson > > > > --- > > > > > > Does dev_info.rx_desc_lim.nb_min returned by = rte_eth_dev_info_get() > need correction too? > > > > > The minimum number of descriptors stays the same, however, if > choosing the > > minimum number of descriptors you may need to reduce the > rx_free_thresh > > value. > > > However, I think you raise a good point. I'll see about adding a > specific > error message in case the user is using the default threshold and > setting > the min ring size. The applications need some generic code sequence that always works, on = all NICs. E.g. if an application uses rte_eth_dev_adjust_nb_rx_tx_desc() to move a = requested crazy number of descriptors within bounds, and uses the = default values for all other parameters, it should work. Nonetheless, more detailed error messages are always helpful. :-) -Morten