From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <stephen@networkplumber.org> Received: from mail-pl1-f194.google.com (mail-pl1-f194.google.com [209.85.214.194]) by dpdk.org (Postfix) with ESMTP id 7C3152BE5 for <dev@dpdk.org>; Thu, 8 Nov 2018 22:55:23 +0100 (CET) Received: by mail-pl1-f194.google.com with SMTP id p4-v6so7781359plo.5 for <dev@dpdk.org>; Thu, 08 Nov 2018 13:55:23 -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=vx6yzZza2LD76r7pdYTTQTm/BkrgGeqEBwoVQOCvpAs=; b=aYpEuZ7ZPSWN3S833aqBKt1b2Zp9FYkdRYef7Xgfk15XuOoXHhY684xS/vJ5B38ryv XP603me4fotN5YAHd+77oOZKmuW92J+FKjfgOQmyCqnhvsSWrs1wmRlac/mIK0lypBz2 4jU8ghcozwQL4ka4oZU/nAVHHmtNEw/dHYKg6HS3SO8CNJsInwwcuyZ24BaLuBp+a72d lP6ArX/7i533gWfbRGwwnEgmKPUS1+rFEF2dnRETNTbOCo92wH3NNOM0RnXr7Dbwnqzs nq6qVmudemOKfj2PnzdZDKI6sfushx0q+2Rjv3J3qKMoxiH3/zLljgijlrPpVlafEmmw MPcg== 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=vx6yzZza2LD76r7pdYTTQTm/BkrgGeqEBwoVQOCvpAs=; b=ua/HdLhfJWwa9qDJfoaG/mFH1ArIl0VZr3OZ0CK53T3XpA16RMgTpgG9StkV0o/fE0 ukz6O4JAM3ogJHS7nwv5+/gkRjSj+IfI93HhjAiu8ybErO4RGoJ1xacdretWrYeiYSF/ QOaCEzLPolW5bDQ6Z7t+DOssNhvVvHBotQn/phqB6lhA3zAMu0KKW8Pjuq3C3Mwssjuo wSy0X7Jh96YEkqbjO0eDJzKqKUx76V7FzSklAeS38k392JC0Ga6SWNi4idUWzkF/rUo0 vAaTKhvJ+WEMfCppXh9bhhbn6rLQz2BS3Nrk5KZMp6+croRhTAPCyrL/HTJ/8cB7hrwE 1uPg== X-Gm-Message-State: AGRZ1gKaONEkgPaf75d2d3uVFoODZRrfJ7/FrdqyHexm+S1OR/gSVZHA 8bAZdlxczQ6wAndJP0DWS+L62g== X-Google-Smtp-Source: AJdET5eWMskdmc/ZDhDpsdRjnarYoQk8YT4Qs7OlZDQl7HdAb3JNo8uH4GpaKulzhiXbknhkSzvevA== X-Received: by 2002:a17:902:274a:: with SMTP id j10-v6mr4274619plg.312.1541714122354; Thu, 08 Nov 2018 13:55:22 -0800 (PST) Received: from shemminger-XPS-13-9360 ([167.220.2.154]) by smtp.gmail.com with ESMTPSA id g8-v6sm4822526pfh.57.2018.11.08.13.55.22 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 08 Nov 2018 13:55:22 -0800 (PST) Date: Thu, 8 Nov 2018 13:55:20 -0800 From: Stephen Hemminger <stephen@networkplumber.org> To: Jeff Guo <jia.guo@intel.com> Cc: ferruh.yigit@intel.com, konstantin.ananyev@intel.com, anatoly.burakov@intel.com, thomas@monjalon.net, bernard.iremonger@intel.com, dev@dpdk.org, helin.zhang@intel.com, gaetan.rivet@6wind.com, qi.z.zhang@intel.com, arybchenko@solarflare.com, bruce.richardson@intel.com, matan@mellanox.com, shaopeng.he@intel.com Message-ID: <20181108135520.2037ce6f@shemminger-XPS-13-9360> In-Reply-To: <4bcbd2be-240e-9f60-86f8-f0d9ca7e1293@intel.com> References: <1541583691-145432-1-git-send-email-jia.guo@intel.com> <1541583691-145432-3-git-send-email-jia.guo@intel.com> <20181107113344.79229734@shemminger-XPS-13-9360> <4bcbd2be-240e-9f60-86f8-f0d9ca7e1293@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH 2/2] but/pci: fix fd close for hot-unplug X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions <dev.dpdk.org> List-Unsubscribe: <https://mails.dpdk.org/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://mails.dpdk.org/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <https://mails.dpdk.org/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> X-List-Received-Date: Thu, 08 Nov 2018 21:55:23 -0000 On Thu, 8 Nov 2018 11:10:29 +0800 Jeff Guo <jia.guo@intel.com> wrote: > hi, stephen > > On 11/8/2018 3:33 AM, Stephen Hemminger wrote: > > On Wed, 7 Nov 2018 17:41:31 +0800 > > Jeff Guo <jia.guo@intel.com> wrote: > > > >> When device is hot-unplugged, the device fd will be deleted in kernel. > >> Then in the progress of detaching device, if it try to close the fd, > >> it will cause a kernel crash, which shown a kernel null pointer error. > > If this happens, then it is a kernel bug and the kernel should be fixed. > > Working around it in userspace is not a great long term solution. > > > agree with you. The key is sometime hold by kernel. But i think it is at > least reasonable for avoiding no-use process in user space, whatever > kernel's behavior. I am not sure if there is any better idea we can > find, but seems it is an option now. Are you using igb_uio? If so the problem is an DPDK supplied driver. Let's fix that. What is the backtrace on kernel crash.