From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH] net: core: improve the tx_hash calculating Date: Fri, 1 Jun 2018 11:58:25 +0300 Message-ID: <759948ce-08a8-88bb-c57d-faee2f5bf414@cogentembedded.com> References: <1527761641-22034-1-git-send-email-xiangxia.m.yue@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit To: Tonghao Zhang , netdev@vger.kernel.org Return-path: Received: from mail-lf0-f66.google.com ([209.85.215.66]:34426 "EHLO mail-lf0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750724AbeFAI60 (ORCPT ); Fri, 1 Jun 2018 04:58:26 -0400 Received: by mail-lf0-f66.google.com with SMTP id o9-v6so13734514lfk.1 for ; Fri, 01 Jun 2018 01:58:26 -0700 (PDT) In-Reply-To: <1527761641-22034-1-git-send-email-xiangxia.m.yue@gmail.com> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: Hello! On 5/31/2018 1:14 PM, Tonghao Zhang wrote: > Use the % instead of while, and it may simple code and improve > the calculating. The real_num_tx_queues has been checked when > allocating and setting it. > > Signed-off-by: Tonghao Zhang > --- > net/core/dev.c | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/net/core/dev.c b/net/core/dev.c > index 1844d9b..edc5b75 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -2617,15 +2617,13 @@ void netif_device_attach(struct net_device *dev) > */ > static u16 skb_tx_hash(const struct net_device *dev, struct sk_buff *skb) > { > - u32 hash; > u16 qoffset = 0; > u16 qcount = dev->real_num_tx_queues; > > if (skb_rx_queue_recorded(skb)) { > - hash = skb_get_rx_queue(skb); > - while (unlikely(hash >= qcount)) > - hash -= qcount; > - return hash; > + /* When setting the real_num_tx_queues, we make sure > + * real_num_tx_queues != 0. */ In the networking code, multiline comments should look like: /* bla * bla */ > + return skb_get_rx_queue(skb) % qcount; > } > > if (dev->num_tc) { MBR, Sergei