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 824F1A0352; Tue, 8 Feb 2022 19:42:07 +0100 (CET) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 576E241147; Tue, 8 Feb 2022 19:42:07 +0100 (CET) Received: from mail-pf1-f170.google.com (mail-pf1-f170.google.com [209.85.210.170]) by mails.dpdk.org (Postfix) with ESMTP id 7DDD041145 for ; Tue, 8 Feb 2022 19:42:05 +0100 (CET) Received: by mail-pf1-f170.google.com with SMTP id y5so368pfe.4 for ; Tue, 08 Feb 2022 10:42:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=J0RKGikJX22VLGUuGWFs0RvwpgwjOvytfoJYvHVFUlU=; b=0V4xzGjj8l88RwCkrC5eKpiDSHWVikkD2tVeG0LijvOBu1tJLV2ziMY5h3MoHtKxGz ZzgPTWPDaeXpTFW7LA4o+h8A1/AnUrvKvC8fU9I/G2XRIg44Bcq71y2JhavO/zC7U+4x jykK5X4+vzIrS3J8Qolsn0f0an0bWxSC4HtCkpcGuZ0aNNaaYgIPzkVMTxOeuOkB9sV7 8IShEKYAM26rRjMYmeRoypnVUfSyYfKh6SqmhVSwKc0kOJYML1rq4nofXa2UylxHe82H EfHutIRriJju2bleqfWTSuBwehVVWV9huvo56yJ8W9pncQYWNy11UbGPJ2C0QfderSpc 9SQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=J0RKGikJX22VLGUuGWFs0RvwpgwjOvytfoJYvHVFUlU=; b=Vgdf4coAuGFxMzaG98QRFKX8R6B5VKb+mIcxmpr0U5NxRktRJwUaYMnHBMnlUK+0mh Y0OuoXRGkN4KdkaB/dl9Qoz65KOejH77lJrzXCngDJ3/DhR+oHxKEnwbt0BjqoXziieY 8IzutHsWBtCQfgZAdYXb6lXzFSz8gWJzfegQ0ojNuvLBy1oB03Z2cW83FjZc3xeN4Rca lkeQ4eQjG4enpNpOFktJcG4wQqeLt5qUcYpR4NYxJQa6mh9cwDpPxB+13AcA0NtLs1oZ bq/0gMRZ2xlclCXB+bAPgDuidbX5X4YAYM5w5I3i9sUaSHehTCkNomG1Rf04VomfulQU 4KMw== X-Gm-Message-State: AOAM5324LXMf13xFJg/rcgdX2fX4M6/vSlgWXlbRqwV6AgU70juswkON WOhWWKunEC5eW3N3/OpZFDKu6g== X-Google-Smtp-Source: ABdhPJzx2pOtRiTkdeHa2sF3oi9cIzj6n6xH/ws3961/PRDFnfQhT0QvxySnO70l9nf08NDrgNPTRg== X-Received: by 2002:a63:7f54:: with SMTP id p20mr1412252pgn.304.1644345724342; Tue, 08 Feb 2022 10:42:04 -0800 (PST) Received: from hermes.local (204-195-112-199.wavecable.com. [204.195.112.199]) by smtp.gmail.com with ESMTPSA id pg2sm4110413pjb.54.2022.02.08.10.42.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Feb 2022 10:42:03 -0800 (PST) Date: Tue, 8 Feb 2022 10:42:01 -0800 From: Stephen Hemminger To: Ferruh Yigit Cc: Ciara Loftus , , Subject: Re: [PATCH v3] net/af_xdp: re-enable secondary process support Message-ID: <20220208104201.6afef73b@hermes.local> In-Reply-To: <6e2bbf05-102f-f84d-cc51-3663dc270015@intel.com> References: <20220204125436.30397-1-ciara.loftus@intel.com> <20220208134800.52142-1-ciara.loftus@intel.com> <20220208094557.1fd90122@hermes.local> <6e2bbf05-102f-f84d-cc51-3663dc270015@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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 On Tue, 8 Feb 2022 18:00:27 +0000 Ferruh Yigit wrote: > On 2/8/2022 5:45 PM, Stephen Hemminger wrote: > > On Tue, 8 Feb 2022 13:48:00 +0000 > > Ciara Loftus wrote: > > > >> +- **Secondary Processes** > >> + > >> + Rx and Tx are not supported for secondary processes due to the single-producer > >> + single-consumer nature of the AF_XDP rings. However other operations including > >> + statistics retrieval are permitted. > >> + The maximum number of queues permitted for PMDs operating in this model is 8 > >> + as this is the maximum number of fds that can be sent through the IPC APIs as > >> + defined by RTE_MP_MAX_FD_NUM. > >> + > > > > This seems like a restriction that is true for most devices in DPDK. > > Most other devices also have restriction that on queues; > > the hardware descriptor ring can only be used by one thread at a time. > > Is this different with AF_XDP? > > I asked the same on v2 :) and Ciara explained the reason, it is on v2 discussion thread. The wording of the message is what confused me. It would be better to change: due to the single-producer single-consumer nature of the AF_XDP rings to due to memory mapping of the AF_XDP rings being assigned by the kernel in the primary process only.