From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751845AbcF3Gvu (ORCPT ); Thu, 30 Jun 2016 02:51:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56793 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750969AbcF3Gvs (ORCPT ); Thu, 30 Jun 2016 02:51:48 -0400 Subject: Re: [PATCH net-next V3 5/6] net: introduce NETDEV_CHANGE_TX_QUEUE_LEN To: John Fastabend , mst@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, davem@davemloft.net References: <1467258779-3539-1-git-send-email-jasowang@redhat.com> <1467258779-3539-6-git-send-email-jasowang@redhat.com> <5774A67B.1060802@gmail.com> <5774AA46.3090604@redhat.com> <5774B553.5070701@redhat.com> Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, eric.dumazet@gmail.com, brouer@redhat.com From: Jason Wang Message-ID: <5774BF74.9000508@redhat.com> Date: Thu, 30 Jun 2016 14:43:00 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <5774B553.5070701@redhat.com> 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 [10.5.110.29]); Thu, 30 Jun 2016 06:43:06 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016年06月30日 13:59, Jason Wang wrote: > > > On 2016年06月30日 13:12, Jason Wang wrote: >> >> >> On 2016年06月30日 12:56, John Fastabend wrote: >>> On 16-06-29 08:52 PM, Jason Wang wrote: >>>> This patch introduces a new event - NETDEV_CHANGE_TX_QUEUE_LEN, this >>>> will be triggered when tx_queue_len. It could be used by net device >>>> who want to do some processing at that time. An example is tun who may >>>> want to resize tx array when tx_queue_len is changed. >>>> >>>> Signed-off-by: Jason Wang >>>> --- >>>> include/linux/netdevice.h | 1 + >>>> net/core/net-sysfs.c | 15 ++++++++++++++- >>>> 2 files changed, 15 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h >>>> index e84d9d2..7dc2ec7 100644 >>>> --- a/include/linux/netdevice.h >>>> +++ b/include/linux/netdevice.h >>>> @@ -2237,6 +2237,7 @@ struct netdev_lag_lower_state_info { >>>> #define NETDEV_PRECHANGEUPPER 0x001A >>>> #define NETDEV_CHANGELOWERSTATE 0x001B >>>> #define NETDEV_UDP_TUNNEL_PUSH_INFO 0x001C >>>> +#define NETDEV_CHANGE_TX_QUEUE_LEN 0x001E >>>> int register_netdevice_notifier(struct notifier_block *nb); >>>> int unregister_netdevice_notifier(struct notifier_block *nb); >>>> diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c >>>> index 7a0b616..6e4f347 100644 >>>> --- a/net/core/net-sysfs.c >>>> +++ b/net/core/net-sysfs.c >>>> @@ -322,7 +322,20 @@ NETDEVICE_SHOW_RW(flags, fmt_hex); >>>> static int change_tx_queue_len(struct net_device *dev, unsigned >>>> long new_len) >>>> { >>>> - dev->tx_queue_len = new_len; >>>> + int res, orig_len = dev->tx_queue_len; >>>> + >>>> + if (new_len != orig_len) { >>>> + dev->tx_queue_len = new_len; >>>> + res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, >>>> dev); >>>> + res = notifier_to_errno(res); >>>> + if (res) { >>>> + netdev_err(dev, >>>> + "refused to change device tx_queue_len\n"); >>>> + dev->tx_queue_len = orig_len; >>>> + return -EFAULT; >>>> + } >>>> + } >>>> + >>>> return 0; >>>> } >>>> >>> Acked-by: John Fastabend >>> >>> Great timing I was just looking into this because I need it for the >>> qdisc side. >>> >>> It looks like this covers the sysfs change but the tx_queue_len can >>> also be changed via rtnetlink as well. So we need another patch for >>> that path right? >>> >>> if (tb[IFLA_TXQLEN]) { >>> unsigned long value = nla_get_u32(tb[IFLA_TXQLEN]); >>> >>> if (dev->tx_queue_len ^ value) >>> status |= DO_SETLINK_NOTIFY; >>> >>> dev->tx_queue_len = value; >>> } >>> >>> Thanks, >>> John >>> >> >> Right, will do this in next version. >> >> Thanks > > Ok, since Michael has acked on the series, will prepare a patch on top. > > Thanks Since kbuild test robot has found a minor issue on this series, I will post v4 with this fixed. Thanks