From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [RFC net-next 1/2] net: net-porcfs: Reduce rcu lock critical section Date: Mon, 16 Apr 2018 14:07:07 -0700 Message-ID: <4cc44e85-cb5e-502c-30f3-c6ea564fe9ac@gmail.com> References: <20180410170812.18905-1-saeedm@mellanox.com> <20180410.131649.583776764903333305.davem@davemloft.net> <75137dbf-4608-127e-1601-10a3c13e3a32@gmail.com> <1523473143.3402.55.camel@mellanox.com> <1523490467.3587.20.camel@mellanox.com> <3e0f5494-3d5c-06e8-a5b2-12b735390629@gmail.com> <1523560344.3587.40.camel@mellanox.com> <1523911853.4579.19.camel@mellanox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: "netdev@vger.kernel.org" To: Saeed Mahameed , "eric.dumazet@gmail.com" , "davem@davemloft.net" Return-path: Received: from mail-pl0-f68.google.com ([209.85.160.68]:44471 "EHLO mail-pl0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750732AbeDPVHJ (ORCPT ); Mon, 16 Apr 2018 17:07:09 -0400 Received: by mail-pl0-f68.google.com with SMTP id s13-v6so3468535plq.11 for ; Mon, 16 Apr 2018 14:07:09 -0700 (PDT) In-Reply-To: <1523911853.4579.19.camel@mellanox.com> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 04/16/2018 01:50 PM, Saeed Mahameed wrote: > > Dave, Eric, I would like to know whether it is ok to have this change > in the kernel (make get_stats ndo "might sleep")? I really didn't get > any convincing feedback to not do this change. Fact that you were not convinced does not mean you were right. I would rather not change the current behavior and risk nasty bugs. Having SNMP daemons blocked while some device is sleeping in its ndo_get_stats() is concerning, since it is currently an immediate operation. ethtool -S can definitely sleep if you need fancy stats.