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 2CE05A0542 for ; Wed, 16 Nov 2022 22:52:14 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 20364410D3; Wed, 16 Nov 2022 22:52:14 +0100 (CET) Received: from mail-lj1-f173.google.com (mail-lj1-f173.google.com [209.85.208.173]) by mails.dpdk.org (Postfix) with ESMTP id 9FDBA40DFB; Wed, 16 Nov 2022 22:52:11 +0100 (CET) Received: by mail-lj1-f173.google.com with SMTP id a15so172923ljb.7; Wed, 16 Nov 2022 13:52:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=fPO0CEBHuD3/KzKGv1eDNgheueO6B/mXQiBygEMWOSk=; b=NHXJrjH8ncbMY0bH/JxN+3YRKpyVtTXB9U4igZiXILFYGKD2EwzDknRKkLtArekOYC UzHi4DJv5a6cShL/rrOKrgvGUvlZlyUkBug9gc+YmDyjrGViSL+e0+9T/tNBEz/kTiCI 2YDIiTuNktRJjM15b27k4oicdHhCobku0eT2CleBLpvWX5W4JecHv5+dyhwXDD5h7cQY cD956KzNj+ojmEJPvlZNoHkQfC40MniDEJqfKHhb2it8s1DrWDQMYIRpcJ5T/isH+Y2C PNQ4OyfohLRTVV0EEKh/6SvFPJWPe/L0frGz9LJg2NApnkI5+FjtkpkFzWzBqA8SjU+M 2jqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=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=fPO0CEBHuD3/KzKGv1eDNgheueO6B/mXQiBygEMWOSk=; b=wiH4k02gN0cNASGnidcq09w3TrhcUX01EmymYQVvBXmiQfDFUEl7zDAbd15e8k3QZQ g13QQuN/IVB8clqiDdSQH6KQmk1hATLYpU/ufD9mXKc35+WmMuscGQQVavCl+iR2oVvn m0iGO6Kf5FEg3C93+CwGDf3crL92PqSb5hiYO818KntmDpOXIV5f9/xSdSEn3cuZZg/R eg6iAlvh8jADE4q3v8Xq3cANHRAY3i/CC71RXJkn7xTwD7FheG19k1J17GUQ04NXjzad iMNySdxOeAJftE9Ms6hIbiA0rVGSe1H157T0Gowh5b2SegcZ3H7SqBIjRXcuJ4V2I4Bz E2hw== X-Gm-Message-State: ANoB5pn3c7PUdpzhJ5N+txM0UKNMx1YS5Audn0Ao5rX5sIPVMOw1osyF y7npIuwF4DlMlgTu0gbZe39BkzRjVeGGkwrziRI= X-Google-Smtp-Source: AA0mqf7Xj8orf1SdQGVIlIil7qXxtBg0GmTO9UJgJg5/DboGc1jIIiSJdR/lh+zOvI6Vchak1B9jXk2+7aSnsTdG9BE= X-Received: by 2002:a2e:b8c3:0:b0:277:2e91:e9d6 with SMTP id s3-20020a2eb8c3000000b002772e91e9d6mr71618ljp.372.1668635530908; Wed, 16 Nov 2022 13:52:10 -0800 (PST) MIME-Version: 1.0 References: <20221110163410.12734-1-lucp.at.work@gmail.com> In-Reply-To: From: Luc Pelletier Date: Wed, 16 Nov 2022 16:51:59 -0500 Message-ID: Subject: Re: [PATCH] failsafe: fix segfault on hotplug event To: Konstantin Ananyev Cc: "grive@u256.net" , "dev@dpdk.org" , "stable@dpdk.org" , hyonkim@cisco.com, johndale@cisco.com Content-Type: text/plain; charset="UTF-8" X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: stable-bounces@dpdk.org Hi Konstantin, > It is not recommended way to update rte_eth_fp_ops[] contents directly. > There are eth_dev_fp_ops_setup()/ eth_dev_fp_ops_reset() that supposed > to be used for that. Good to know. I see another fix that was made in a different PMD that does exactly the same thing: https://github.com/DPDK/dpdk/commit/bcd68b68415172815e55fc67cf3947c0433baf74 CC'ing the authors for awareness. > About the fix itself - while it might help till some extent, > I think it will not remove the problem completely. > There still remain a race-condition between rte_eth_rx_burst() and failsafe_eth_rmv_event_callback(). > Right now DPDK doesn't support switching PMD fast-ops functions (or updating rxq/txq data) > on the fly. Thanks for the information. This is very helpful. Are you saying that the previous code also had that same race condition? It was only updating the rte_eth_dev structure, but I assume the problem would have been the same since rte_eth_rx_burst() in DPDK versions <=20 use the function pointers in rte_eth_dev, not rte_eth_fp_ops. Can you think of a possible solution to this problem? I'm happy to provide a patch to properly fix the problem. Having your guidance would be extremely helpful. Thanks!