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 A136446487; Wed, 26 Mar 2025 15:47:55 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 6A99440613; Wed, 26 Mar 2025 15:47:55 +0100 (CET) Received: from mail-lf1-f44.google.com (mail-lf1-f44.google.com [209.85.167.44]) by mails.dpdk.org (Postfix) with ESMTP id A6C83402E0 for ; Wed, 26 Mar 2025 15:47:54 +0100 (CET) Received: by mail-lf1-f44.google.com with SMTP id 2adb3069b0e04-54996d30bfbso6441822e87.2 for ; Wed, 26 Mar 2025 07:47:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=iol.unh.edu; s=unh-iol; t=1743000474; x=1743605274; darn=dpdk.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=pJyZscT9jgyThkKCJZ1/lx/PQUYmOdDr89attjb19OU=; b=H9XiuNG/q7T2lnB8nmymcRSN2kyEKTiphtrhYbWshr9+PW5XQJ1VLuGTtgDLtLacs3 9xmiqpVNVg+cAu8cDu8XMbVHCcS9LNb2L/ebym9GXwZp3nlnLtb3bSnfsLWd/lXoFUe9 qjiRNoj4chwG+qd95dQuoc7zSdFWYhBlbdab4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1743000474; x=1743605274; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=pJyZscT9jgyThkKCJZ1/lx/PQUYmOdDr89attjb19OU=; b=R83BrHh5QV8xRCmnDtRJx4rtOXxak4xvM9Q34IoqSDmTUKPNcuJx6aXA5YpsAGoY9g bZWKXKMxWZXVI4ChaW5hKqUwIJrQASZgZ7tLePOVQjPyttMU+mSlNxk/SiQLvh1L2I42 OMfqcO/Ky/ITFHEKEK49N4ktLDqg9b0oxuXOunTE6nuN9mqhYSsFCO9+m4E1smSuTiT8 whv+b2OxST+JKFbUD38aAXpbgab5p/C5NKyoyaxq8tOfAvYDZutRUbPBXPFKoTxScH2p FFsZQkMRTh9hruCMUruvPyhF2RHVecJdae9XhlEhywToScTL1ElQ5BBHXl8++9VtLb/p 9b5w== X-Forwarded-Encrypted: i=1; AJvYcCUusbW/OPhx/2Q/ACtbesG7KmlmuvLs1TvgxggLPBY5w2M/gA1m5WWDKAAjViiujc2+sww=@dpdk.org X-Gm-Message-State: AOJu0Yx+l6K/PpZUV4LkPheVer/Eov/YSuLKqAxpu45YS1vSMoO9jPVR j4qf0ExoS50Pkl9yq6eyjL/2+jvYlRsvj9LJopqPhUxpBcmSZTpiuydGNTw4CTSHQwIg9uDykh3 QSZ+3XaH4dA+XXAt0yRk4H8/dgUBWO5NLpWhf9A== X-Gm-Gg: ASbGnctCwWyH0m6sSOhcpjSv9PkGQSq1yMh2Mk7MHvsAO5JuA7Mo5iwMoCJjLVwatQJ 6XvEwenkBOEnUaiLVNtj47nmSJYhyFVoLDunLijXVWlks/2Fh73MpuRQRBDlTSpK7P+avqDDZg2 DJnJw9pOoRerHVKMCKAaOZP53R2WuEneU1EfB3bQCq8N0wwJ/f6iUpbbDXZKtM X-Google-Smtp-Source: AGHT+IEoVgE8ReMg22C9WIRoY+Zb3CexaEWve4lz0vdqMrgEjYvBL2zGLL13RsQ8j7DZXClyA4PFVma/CQjT65ykFtg= X-Received: by 2002:a05:6512:1589:b0:549:4bf7:6463 with SMTP id 2adb3069b0e04-54ad65004abmr8117515e87.44.1743000473876; Wed, 26 Mar 2025 07:47:53 -0700 (PDT) MIME-Version: 1.0 References: <98CBD80474FA8B44BF855DF32C47DC35E9FB37@smartserver.smartshare.dk> <20250321085259.095bd234@hermes.local> <98CBD80474FA8B44BF855DF32C47DC35E9FB3B@smartserver.smartshare.dk> In-Reply-To: <98CBD80474FA8B44BF855DF32C47DC35E9FB3B@smartserver.smartshare.dk> From: Cody Cheng Date: Wed, 26 Mar 2025 10:47:42 -0400 X-Gm-Features: AQ5f1Jpeqo-Dw7d7cB34avSA4LNRdMuPJILea2WOOJzfY1ToFrLLduYMoloP39s Message-ID: Subject: Re: Clarification on Minimum Supported Kernel Version for DPDK To: =?UTF-8?Q?Morten_Br=C3=B8rup?= Cc: Stephen Hemminger , Kevin Traynor , Bruce Richardson , techboard@dpdk.org, Tyler Retzlaff , Thomas Monjalon , David Marchand , dev@dpdk.org, Ali Alnubani , galco@nvidia.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable 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 I=E2=80=99ll set up the CI testing environment on kernel 4.19 as per the current minimum requirement then. Thanks, Cody Cheng On Sat, Mar 22, 2025 at 9:02=E2=80=AFAM Morten Br=C3=B8rup wrote: > > > From: Stephen Hemminger [mailto:stephen@networkplumber.org] > > Sent: Friday, 21 March 2025 16.53 > > > > On Fri, 21 Mar 2025 07:28:45 +0100 > > Morten Br=C3=B8rup wrote: > > > > > @Kevin, @Stephen, @Bruce, > > > > > > I cannot reliably answer Cody's question, and it may need further > > discussion. > > > > > > What is your opinion on minimum Linux kernel version requirements? > > > > > > @Thomas: In the future, the DPDK release notes should mention the > > minimum Linux kernel requirements. > > > > > > > From: Cody Cheng [mailto:ccheng@iol.unh.edu] > > > > Sent: Thursday, 20 March 2025 21.28 > > > > > > > > Hi Morten, > > > > > > > > I am in the process of setting up a test environment at the UNH > > DPDK > > > > Community Test Lab that follows the minimum supported kernel > > version > > > > for DPDK. According to the DPDK documentation, the minimum > > supported > > > > kernel version is 4.19. However, the oldest long term stable kernel > > > > version listed on kernel.org is 5.4.291. > > > > > > > > Should the test environment be set up on kernel version 4.19 or > > > > 5.4.291? > > > > > > The kernel 4.19 support stems from still supporting RHEL/CentOS 7. > > > I wonder if this exception mentioned in the documentation [1] is > > still valid, or if we should bump it to RHEL/CentOS 8, which ships with > > kernel 4.18 [1]. > > > > > > RHEL/CentOS 7 support was discussed at by tech board long ago [2], > > but I cannot find a conclusion about the kernel version; the discussion > > was mostly about compiler support. > > > > > > [1]: https://doc.dpdk.org/guides/linux_gsg/sys_reqs.html#system- > > software > > > [2]: > > https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/8/htm > > l-single/8.0_release_notes/index#overview > > > [3]: https://mails.dpdk.org/archives/dev/2023-February/263516.html > > > > My opinion has always been that DPDK only offers certain guarantees > > about testing: > > - oldest current LTS > > - oldest supported version of Redhat/Ubuntu/SUSE enterprise kernels > > > > after that in the embedded space, the user is likely to be ok but any > > kernel > > related issues are their problem not the communities to deal with. > > Generally, if some new DPDK feature requires a new kernel (or new kernel = feature), the details should be mentioned in the release notes. > And preferably, that feature should degrade gracefully when the feature i= s not present. > > For the embedded space, we could support the oldest current version avail= able as Super LTS [4], which is 4.4. And for now, we could stick with the s= econd oldest, 4.19, which is what we currently have. > > [4]: https://wiki.linuxfoundation.org/civilinfrastructureplatform/start#k= ernel_maintainership > > Some old kernel version might not be officially supported by the Kernel c= ommunity, but an embedded vendor might have tested the relevant features ex= tensively and thus trust it more than some new and officially supported ver= sion. > So let's not require a newer version than we absolutely must, on technica= l grounds. > It seems that kernel 4.19 is the current minimum requirement, so let's st= ick with that, until there are valid technical reasons for requiring a newe= r version. > > Anyway, it seems we need to clarify the policy for kernel version require= ments. > It's easy regarding the distros; DPDK running on those require their ship= ped kernel version, at minimum. > It's for everything else clarification is needed. > > And it's not just embedded. Virtual appliances can be tricky too... with = our SmartShare VM we had to add support for running as a guest under an anc= ient QEMU host version, because that is the hypervisor used by one of the b= ig system providers in our most important target market. > > In non-cloud market segments, a lot of really old stuff is still being us= ed in production, working perfectly fine. > > > > > The two parts most likely to cause issues are vfio-pci and vhost > > related stuff. > > There is also small chance of issues with the memory handling in EAL. > And maybe handling of many CPU cores, and most likely something related t= o the new cache steering feature. >