From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932812AbeB1RWl (ORCPT ); Wed, 28 Feb 2018 12:22:41 -0500 Received: from shards.monkeyblade.net ([184.105.139.130]:49372 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753414AbeB1RWc (ORCPT ); Wed, 28 Feb 2018 12:22:32 -0500 Date: Wed, 28 Feb 2018 12:22:31 -0500 (EST) Message-Id: <20180228.122231.1811613646832502397.davem@davemloft.net> To: jasowang@redhat.com Cc: mst@redhat.com, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net] virtio-net: disable NAPI only when enabled during XDP set From: David Miller In-Reply-To: <1519813204-10002-1-git-send-email-jasowang@redhat.com> References: <1519813204-10002-1-git-send-email-jasowang@redhat.com> X-Mailer: Mew version 6.7 on Emacs 25.3 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jason Wang Date: Wed, 28 Feb 2018 18:20:04 +0800 > We try to disable NAPI to prevent a single XDP TX queue being used by > multiple cpus. But we don't check if device is up (NAPI is enabled), > this could result stall because of infinite wait in > napi_disable(). Fixing this by checking device state through > netif_running() before. > > Fixes: 4941d472bf95b ("virtio-net: do not reset during XDP set") > Signed-off-by: Jason Wang Yes, mis-paired NAPI enable/disable are really a pain. Probably, we can do something in the interfaces or mechanisms to make this less error prone and less fragile. Anyways, applied and queued up for -stable, thanks!