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: Wed, 11 Apr 2018 19:59:56 -0700 Message-ID: <3e0f5494-3d5c-06e8-a5b2-12b735390629@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> 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-qk0-f194.google.com ([209.85.220.194]:34476 "EHLO mail-qk0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751845AbeDLDAB (ORCPT ); Wed, 11 Apr 2018 23:00:01 -0400 Received: by mail-qk0-f194.google.com with SMTP id g7so4520230qkm.1 for ; Wed, 11 Apr 2018 20:00:01 -0700 (PDT) In-Reply-To: <1523490467.3587.20.camel@mellanox.com> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 04/11/2018 04:47 PM, Saeed Mahameed wrote: > > Well if we allow devices to access HW counters via FW command > interfaces in ndo_get_stats and by testing mlx5 where we query up to 5 > hw registers, it could take 100us, still this is way smaller than 10sec > :) and it is really a nice rate to fetch HW stats on demand. If hardware stats are slower than software ones, maybe it is time to use software stats, instead of changing the whole stack ? There are very few devices drivers having issues like that.