From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH net] net: Correct wrong skb_flow_limit check when enable RPS Date: Thu, 10 May 2018 17:55:47 -0700 Message-ID: <721ce144-2470-6124-1edd-cc7a343994a6@gmail.com> References: <1525940884-21067-1-git-send-email-gfree.wind@vip.163.com> <5ac360c4-0936-9c12-56cb-f81f08c925e6@gmail.com> <654af0ff.3e1.1634c90380e.Coremail.gfree.wind@vip.163.com> Mime-Version: 1.0 Content-Type: text/plain; charset=gbk Content-Transfer-Encoding: 7bit Cc: "davem@davemloft.net" , daniel@iogearbox.net, jakub.kicinski@netronome.com, David Ahern , "netdev@vger.kernel.org" To: Gao Feng , Eric Dumazet Return-path: Received: from mail-pg0-f67.google.com ([74.125.83.67]:40488 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752339AbeEKAzu (ORCPT ); Thu, 10 May 2018 20:55:50 -0400 Received: by mail-pg0-f67.google.com with SMTP id l2-v6so1688388pgc.7 for ; Thu, 10 May 2018 17:55:49 -0700 (PDT) In-Reply-To: <654af0ff.3e1.1634c90380e.Coremail.gfree.wind@vip.163.com> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 05/10/2018 05:18 PM, Gao Feng wrote: > At 2018-05-10 21:02:55, "Eric Dumazet" wrote: >> >> >> On 05/10/2018 01:28 AM, gfree.wind@vip.163.com wrote: >>> From: Gao Feng >>> >>> The skb flow limit is implemented for each CPU independently. In the >>> current codes, the function skb_flow_limit gets the softnet_data by >>> this_cpu_ptr. But the target cpu of enqueue_to_backlog would be not >>> the current cpu when enable RPS. As the result, the skb_flow_limit checks >>> the stats of current CPU, while the skb is going to append the queue of >>> another CPU. It isn't the expected behavior. >>> >>> Now pass the softnet_data as a param to softnet_data to make consistent. >>> >> >> Please add a correct Fixes: tag > > Thanks Eric. > > I have one question about the "Fixes: tag". > Most of patches are bug fixes, but when need to add the "Fixes: tag", and when not ? > > I'm not clear about it. Could you explain it please? > For this particular patch, since you have not CC Willem (author of the patch), I found very useful that you did a search to find out. Once you found which commit added the problem, simply add the Fixes: tag and CC: the author. Doing so saves us (stable teams, reviewers, maintainers) a lot of time really. In my opinion, Fixes: tags should be mandatory when applicable. > Best Regards > Feng > >> >> By doing so, you will likely add a CC: tag to make sure the author of the code >> will receive your email and give feed back. >> >> Thanks ! >>