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 ACE13A034F; Fri, 26 Feb 2021 16:49:23 +0100 (CET) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 7347D407FF; Fri, 26 Feb 2021 16:49:23 +0100 (CET) Received: from mail-pl1-f171.google.com (mail-pl1-f171.google.com [209.85.214.171]) by mails.dpdk.org (Postfix) with ESMTP id EE52940692 for ; Fri, 26 Feb 2021 16:49:21 +0100 (CET) Received: by mail-pl1-f171.google.com with SMTP id f8so5504993plg.5 for ; Fri, 26 Feb 2021 07:49:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=n8c3S4JLLZTY0elolQ6f2xaPQYwNCX56NEYJmvFryH0=; b=kXxmSfAgNHPsLw41aMq7pyvMTehYQ4Uys0sicXSmfdwsVN+icw32btAFvshNKh2Pwq ObqSh40ivJ8bFm2z4XKo42U0s3yTQPVZeQP4obd6GQOPYKlLl+1pqT8Ztx/AFFKN/Iu+ GuD+3FbL/NHJX1N7lhBg//knJKUsyR/z36jaBa49EaOeTGtquV1fHdCdhVFySQhy0xM2 vsA1GFmzyokRg4TeZqtsxTK8iWYbDa+fU3PUz2lVRxiHK3Ks+x275+dixppRK6qaLir6 4Yet94y9WTmLDWTmevPUPgLZwcMWrd8vZ/p5ZhmXW/LNS8VUvnuNWozx6uGW8MLrMrUU MuNw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=n8c3S4JLLZTY0elolQ6f2xaPQYwNCX56NEYJmvFryH0=; b=eYGhWOqu9l2m0ePJ0OGWwLY80vEcgnXrwsbmAboRkG6sbz1CYQbOOs0dw4iIrOCgUz 6Dn0KF+jc6Jfa5D4wpJYArBUOZ9zHtWx3Q230SWluK26J5c4A49vRKV3e7m7eYp8kr1t lpWGy3A94SaswnRtQO71tub1WsY9e08EkdEItkUSKjHzs4EOmm633toBljXgQd2tkUcc aEo5teAM7Kedau+o3FYXuj+mzEz/C5DvcicEKVA4E2WZrbXNJ5Y/7ovCXpPc+0XdA8iU Kntu4G5b9J78yve6+3W72t5CK29xI/SpEhBufHbppR/jscMsWOvFbJ+j5NSuLSmtyvif Nvzw== X-Gm-Message-State: AOAM532ErnJM3ZH1Icy7pqghusqArumPbRZKvn2AwxwH1NwATfKNsROl 5ivKim3KEYsjdDUNyxkl8CqrKg== X-Google-Smtp-Source: ABdhPJzDjU3O5weOzLKXihbrQzZR/j7ue1XVfcirgY+zU7I2hxkhPu1HGUgG1rpx3FhMQT3R2VAqgw== X-Received: by 2002:a17:90a:e001:: with SMTP id u1mr4173562pjy.178.1614354561172; Fri, 26 Feb 2021 07:49:21 -0800 (PST) Received: from hermes.local (76-14-218-44.or.wavecable.com. [76.14.218.44]) by smtp.gmail.com with ESMTPSA id x9sm9087530pjp.3.2021.02.26.07.49.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 26 Feb 2021 07:49:20 -0800 (PST) Date: Fri, 26 Feb 2021 07:48:17 -0800 From: Stephen Hemminger To: Igor Ryzhov Cc: Elad Nachman , Ferruh Yigit , dev Message-ID: <20210226074817.7e9e0a71@hermes.local> In-Reply-To: References: <20201126144613.4986-1-eladv6@gmail.com> <20210225143239.14220-1-eladv6@gmail.com> <20210225143239.14220-2-eladv6@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH 2/2] kni: fix rtnl deadlocks and race conditions v4 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 Sender: "dev" On Fri, 26 Feb 2021 00:01:01 +0300 Igor Ryzhov wrote: > Hi Elad, > > Thanks for the patch, but this is still NACK from me. > > The only real advantage of KNI over other exceptional-path techniques > like virtio-user is the ability to configure DPDK-managed interfaces > directly > from the kernel using well-known utils like iproute2. A very important part > of this is getting responses from the DPDK app and knowing the actual > result of command execution. > If you're making async requests to the application and you don't know > the result, then what's the point of using KNI at all? > > Igor Do you have a better proposal that keeps the request result but does not call userspace with lock held. PS: I also have strong dislike of KNI, as designed it would have been rejected by Linux kernel developers. A better solution would be userspace version of something like devlink devices. But doing control operations by proxy is a locking nightmare.