From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751898AbcF3F7y (ORCPT ); Thu, 30 Jun 2016 01:59:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53760 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751034AbcF3F7x (ORCPT ); Thu, 30 Jun 2016 01:59:53 -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> Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, eric.dumazet@gmail.com, brouer@redhat.com From: Jason Wang Message-ID: <5774B553.5070701@redhat.com> Date: Thu, 30 Jun 2016 13:59:47 +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: <5774AA46.3090604@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 [10.5.110.30]); Thu, 30 Jun 2016 05:59:52 +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 13:12, 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