From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6EE51C43461 for ; Wed, 9 Sep 2020 06:37:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2916821741 for ; Wed, 9 Sep 2020 06:37:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599633433; bh=V9NR7nDo2UszOuOP8RDVwdq8XRt9ah6sdjjX5rYls7s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=nAHBjh9gUqh6UlLu8GHysTOM5l8Uxpbj5Vf23F7+LOU1CgF7dVvj3pzuLjK6BKLWk srIHWl+ksiXTYC/LNe+9SSQV3p/oCp0JToHwbjgYyPITlrW+G3Heq/W8c4dkY2ddau WOTWtWI6aDwNT1Y49Z/eYbLz82F+xYfwcgcRkzgs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726408AbgIIGhJ (ORCPT ); Wed, 9 Sep 2020 02:37:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:43572 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725772AbgIIGhI (ORCPT ); Wed, 9 Sep 2020 02:37:08 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F413220936; Wed, 9 Sep 2020 06:37:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599633427; bh=V9NR7nDo2UszOuOP8RDVwdq8XRt9ah6sdjjX5rYls7s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NlwPLZIgF1GL/oHuvSsxzRQI0AHkOimDqAW5+k22UOG/xweMctkbOEjtlJerTdkMZ t7nWuGmH0TygNx0gEVDvPGkfelGdhfgyJj6D4DmjYBwl4SSwYM+nWNfCfj20ufMDSw 2/hAVYXQkW5uztKEQYJ7Hsvg0AF7CJJ4Nf8TeDCU= Date: Wed, 9 Sep 2020 08:37:18 +0200 From: Greg Kroah-Hartman To: Edward Cree Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Alexander Lobakin , "David S. Miller" , Hyunsoon Kim Subject: Re: [PATCH 5.4 086/129] net: core: use listified Rx for GRO_NORMAL in napi_gro_receive() Message-ID: <20200909063718.GA311356@kroah.com> References: <20200908152229.689878733@linuxfoundation.org> <20200908152234.000867723@linuxfoundation.org> <70529b6c-7b00-d760-c0c0-42f0ea5784f3@solarflare.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <70529b6c-7b00-d760-c0c0-42f0ea5784f3@solarflare.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 08, 2020 at 10:35:22PM +0100, Edward Cree wrote: > On 08/09/2020 16:25, Greg Kroah-Hartman wrote: > > From: Alexander Lobakin > > > > commit 6570bc79c0dfff0f228b7afd2de720fb4e84d61d upstream. > > > > Commit 323ebb61e32b4 ("net: use listified RX for handling GRO_NORMAL > > skbs") made use of listified skb processing for the users of > > napi_gro_frags(). > > The same technique can be used in a way more common napi_gro_receive() > > to speed up non-merged (GRO_NORMAL) skbs for a wide range of drivers > > including gro_cells and mac80211 users. > > This slightly changes the return value in cases where skb is being > > dropped by the core stack, but it seems to have no impact on related > > drivers' functionality. > > gro_normal_batch is left untouched as it's very individual for every > > single system configuration and might be tuned in manual order to > > achieve an optimal performance. > > > > Signed-off-by: Alexander Lobakin > > Acked-by: Edward Cree > > Signed-off-by: David S. Miller > > Signed-off-by: Hyunsoon Kim > > Signed-off-by: Greg Kroah-Hartman > I'm not quite sure why this is stable material(it's a performance >  enhancement, rather than a fix).  But if you do want to take it, >  make sure you've also got > c80794323e82 ("net: Fix packet reordering caused by GRO and listified RX cooperation") > b167191e2a85 ("net: wireless: intel: iwlwifi: fix GRO_NORMAL packet stalling") >  in your tree, particularly the latter as without it this commit >  triggers a severe regression in iwlwifi. Hm, that feels bad, I'll go drop this for now. Hyunsoon was the one who asked for this, so I will let them defend the request. I thought they were asking for this because it was a bug fix, but if it is a performance issue, that's fine as long as it doesn't also cause problems :) Hyunsoon, should all of these be taken, and if so, what exactly is the performance increase here? thanks, greg k-h