From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755341AbdK2OO4 (ORCPT ); Wed, 29 Nov 2017 09:14:56 -0500 Received: from shards.monkeyblade.net ([184.105.139.130]:58432 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751980AbdK2OOw (ORCPT ); Wed, 29 Nov 2017 09:14:52 -0500 Date: Wed, 29 Nov 2017 09:14:48 -0500 (EST) Message-Id: <20171129.091448.2012623126704239343.davem@davemloft.net> To: skhare@vmware.com Cc: pv-drivers@vmware.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next] vmxnet3: increase default rx ring sizes From: David Miller In-Reply-To: <20171128211204.12234-1-skhare@vmware.com> References: <20171128211204.12234-1-skhare@vmware.com> X-Mailer: Mew version 6.7 on Emacs 24.5 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Wed, 29 Nov 2017 06:14:52 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Shrikrishna Khare Date: Tue, 28 Nov 2017 13:12:04 -0800 > We often notice rx packet drops due to small default rx ring sizes and > solve the problem by increasing the ring sizes. This patch increases the > default rx ring sizes thereby reducing the probability of rx packet > drops out of the box. > > Signed-off-by: Shrikrishna Khare > Acked-by: Jin Heo > Acked-by: Guolin Yang > Acked-by: Boon Ang That's not enough for me. If you're going to quadruple your default RX ring size I want to hear more about the research you did into the packet drops and whether other things can be done to solve the problem. Is something holding onto the packets unnecessarily long? Is something blocking interrupts (hardware or software)? Is an offload miscoded or misbehaving? Is there a problem with the RX ring replenish algorithm of the driver or it's heuristics? Tell me more about that than just "bumping the RX ring size fixes the problem". Thank you.