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 CCC2845BC0; Tue, 29 Oct 2024 17:09:53 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 88A4D42E48; Tue, 29 Oct 2024 17:09:53 +0100 (CET) Received: from mail-pl1-f169.google.com (mail-pl1-f169.google.com [209.85.214.169]) by mails.dpdk.org (Postfix) with ESMTP id BB50E40261 for ; Tue, 29 Oct 2024 17:09:52 +0100 (CET) Received: by mail-pl1-f169.google.com with SMTP id d9443c01a7336-20cbb1cf324so47849385ad.0 for ; Tue, 29 Oct 2024 09:09:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1730218192; x=1730822992; darn=dpdk.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=11ctgvM+ghV2ZPBFKICtELgG1QTxAyrabsiqbLRGRhY=; b=JmYwHoF49Ln+nAQYdrIlK9R9790YeT7/fkVqZLS+RK+MNAE9TqAuyPWa9cOOgpHslk PZSBAL0qZU0rWXLQUhQxc1VDxTxfCC8Fp25q6KF8k11eosP5tVEo4eIMuPo7vtSsAP+y XAtxbcOppRvomZiyEgQ3eO8qoHuE+URahfmbdfK5MBIPtKwCnDAz9eQKCCcyHZEHR6Bn DiGlwSxAA60g+oe0OWaB0ipxntuO8r4fwlk3zWxGEAmkgCfpVbUbUXvi0GWGFsQm9Dd1 krwBlwWG0WF6+5mrj9WSTONfxrGdawusP4ANVHGRlJiKFQmip52uZFwFtT/mNvybFBUB 4glw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730218192; x=1730822992; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=11ctgvM+ghV2ZPBFKICtELgG1QTxAyrabsiqbLRGRhY=; b=HO0X7rlJSmajFuAjy054NpHKVTPVZY82ceRV6rjX0hS341ojgPO9k5lgroFgA9A3+3 /sZUW2xmTuArDFGUXjOGoJ48N3dzJm+/j9YvUKMBkb8kZdPrFR1hz8OazNKbmFTLr5X6 9jnf/LjVy0KfOqP2In4yleDLGwGEqR55EBKFXB9No2vOvbuA11u7qlHkJLFMKEkKdAXK LpaR0h624ADtdvFaAL/F8t4rVXIPZ+RRAq6xiZ5f7B5jPw/2YxXhJMhY9zr+P19vPi/+ lsAqQSq1dJRwq0/GxqdokH5TVazK4ctAk6pnrcX9QRqxyrsColGL8Cx9GKuH2q79/qP2 9adg== X-Gm-Message-State: AOJu0YwQt/sJF69f+Xj0sudqBATjqT0DfpXVmSV1bGKJx8RVpzjwp4s1 SEIltSom5Wwz3Ea0sQZu1vHnatzyOxSFlF1ZjfVrvNPpYmNf9ZwjmCok3NQSLlc= X-Google-Smtp-Source: AGHT+IGoaz5NqUbEx6qKtaEzDW3CUfe9pYEcaVmW7VAn759Y/ru1d9a5Qw0bvf02EOtxyBZIYcH6uA== X-Received: by 2002:a17:902:d547:b0:20c:d072:c899 with SMTP id d9443c01a7336-210c6ae4d98mr146623405ad.24.1730218191943; Tue, 29 Oct 2024 09:09:51 -0700 (PDT) Received: from hermes.local (204-195-96-226.wavecable.com. [204.195.96.226]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-210bbf4434fsm67790595ad.40.2024.10.29.09.09.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Oct 2024 09:09:51 -0700 (PDT) Date: Tue, 29 Oct 2024 09:09:50 -0700 From: Stephen Hemminger To: Gur Stavi Cc: , "John W. Linville" , Ferruh Yigit Subject: Re: [PATCH v01] net/af_packet: add rollover and defrag options Message-ID: <20241029090950.7a4b314f@hermes.local> In-Reply-To: References: 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, 29 Oct 2024 15:48:05 +0200 Gur Stavi wrote: > net_af_packet PMD multi "queue" support relies on Linux FANOUT capability. > Linux FANOUT is a SW based load balancer that is similar to HW RSS which is > more common for DPDK PMDs. Instead of multiple HW descriptor queues, AF PACKET > uses multiple sockets. > HW RSS will typically drop a packet if its selected RX queue is empty. However, > Linux FANOUT, as a SW load balancer, can be configured to avoid this packet > drop by rolling over to the next socket. > This rollover functionality was ALWAYS enabled in net_af_packet. It is > surrounded by ifdef, but only to allow compilation on ancient Linux versions > that did not have it. > > Since DPDK applications are usually designed for HW based PMDs, this rollover > functionality, which the developers are likely unaware of, could be confusing. > > Another option that is part of Linux FANOUT is DEFRAG that instructs Linux to > compose complete IP packet out of fragments before delivering it to the PACKET > socket. Again, this behavior typically does not exist for HW based PMDs and may > confuse users. > > This patch adds 2 options to control these features: > rollover=[0|1],defrag=[0|1] > For backward compatibility both features are enabled by default even though most > users will probably want both of them disabled. > > Signed-off-by: Gur Stavi > --- Makes sense to expose kernel options. But have all combinations been tested?