From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751471AbcL3FOl (ORCPT ); Fri, 30 Dec 2016 00:14:41 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55428 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750710AbcL3FOk (ORCPT ); Fri, 30 Dec 2016 00:14:40 -0500 Subject: Re: [PATCH net-next V2 3/3] tun: rx batching To: David Miller References: <1482912571-3157-1-git-send-email-jasowang@redhat.com> <1482912571-3157-4-git-send-email-jasowang@redhat.com> <20161229.113506.1833529555874695164.davem@davemloft.net> Cc: mst@redhat.com, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org From: Jason Wang Message-ID: Date: Fri, 30 Dec 2016 13:14:33 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <20161229.113506.1833529555874695164.davem@davemloft.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Fri, 30 Dec 2016 05:14:40 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016年12月30日 00:35, David Miller wrote: > From: Jason Wang > Date: Wed, 28 Dec 2016 16:09:31 +0800 > >> + spin_lock(&queue->lock); >> + qlen = skb_queue_len(queue); >> + if (qlen > rx_batched) >> + goto drop; >> + __skb_queue_tail(queue, skb); >> + if (!more || qlen + 1 > rx_batched) { >> + __skb_queue_head_init(&process_queue); >> + skb_queue_splice_tail_init(queue, &process_queue); >> + rcv = true; >> + } >> + spin_unlock(&queue->lock); > Since you always clear the 'queue' when you insert the skb that hits > the limit, I don't see how the "goto drop" path can be possibly taken. True, will fix this. Thanks