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[23.128.96.18]) by mx.google.com with ESMTP id nb41si3292510ejc.167.2021.07.15.05.31.53; Thu, 15 Jul 2021 05:32:16 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b="Qy/WO4Vr"; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229897AbhGOLwG (ORCPT + 99 others); Thu, 15 Jul 2021 07:52:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44340 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229710AbhGOLwF (ORCPT ); Thu, 15 Jul 2021 07:52:05 -0400 Received: from mail-wm1-x32d.google.com (mail-wm1-x32d.google.com [IPv6:2a00:1450:4864:20::32d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D1B08C06175F; Thu, 15 Jul 2021 04:49:11 -0700 (PDT) Received: by mail-wm1-x32d.google.com with SMTP id l8-20020a05600c1d08b02902333d79327aso2809579wms.3; Thu, 15 Jul 2021 04:49:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=SPeDyGqSFTj9HX+TvNrLA2iuffSVaR/KQ4kPJuR8e/M=; b=Qy/WO4VrpSuEySNBwwsfFYofOH+IjOzbTGpeTrOkiKNb4/6EczG0KPE+o2vY6wLLBE uk+4/8dW+lgtRR2DrK0QRrBjuyHresMx4q/iF07XkrSInCbdDW6co1gor7SRmR+/vxIl lPZ1TGGP2lINEnRrDiWF53s3jRz4EsSrQHwE7PEaJMRJManpe8l0UVzQk7fyuuQlFIK3 s4DAE3MdZ8SfyNAENfyEDdX77VoH+qyyZqhFs+ZpeXmGVgOqavGJbMJ+/kimF6Lhlyeo 7cxKoV7icjbliOzMjnmWJwQ2PSUREXgKpW+5CyQR03hIkg45y+8cGKsNagObqKcdYz/I yfrg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=SPeDyGqSFTj9HX+TvNrLA2iuffSVaR/KQ4kPJuR8e/M=; b=ozGf7kHyBabDYhaoreMvQXb6fLg+gmmCB+3zZbHbP3eifebkVKIzJAyHvjD7Qj58We JdBnohjnm1gQkMs1+5z1dKtxKnvyZGLsHLYNdiSYviIw7OESl7/Nm8KJX0/Cjgm5CYIm V6tpjKnKBWXcOQqabZK886TJS5LbeRK0AqzDedJ5qsy1x7xf0o7H2WZrRdCPQ1bzxeLf y1ygwVxsMJVqXQ1pgj5S6k9RucrXforeEY891PX0yzAfvYQ97uwvxdRHnPRf4JmIdcne q9BEOfBQ39dzF817YalSeV5J7UqR/SISnY0Z8/FRAV4TJ6iFtzjNwCvzg72R9PgvF00S CyhQ== X-Gm-Message-State: AOAM531zq5twUYmZbT1Dn/nVTcOz85ZRqO9qnS+50gkm9CnTIrZFYdKZ 1/KQHdNmtzvi3N7JqBzuT+Y= X-Received: by 2002:a05:600c:5106:: with SMTP id o6mr9981855wms.18.1626349750216; Thu, 15 Jul 2021 04:49:10 -0700 (PDT) Received: from skbuf ([82.76.66.29]) by smtp.gmail.com with ESMTPSA id u12sm6383779wrt.50.2021.07.15.04.49.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Jul 2021 04:49:09 -0700 (PDT) Date: Thu, 15 Jul 2021 14:49:08 +0300 From: Vladimir Oltean To: Lino Sanfilippo Cc: Andrew Lunn , woojung.huh@microchip.com, UNGLinuxDriver@microchip.com, vivien.didelot@gmail.com, f.fainelli@gmail.com, davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] net: dsa: tag_ksz: dont let the hardware process the layer 4 checksum Message-ID: <20210715114908.ripblpevmdujkf2m@skbuf> References: <20210714191723.31294-1-LinoSanfilippo@gmx.de> <20210714191723.31294-3-LinoSanfilippo@gmx.de> <20210714194812.stay3oqyw3ogshhj@skbuf> <20210715065455.7nu7zgle2haa6wku@skbuf> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 15, 2021 at 01:16:12PM +0200, Lino Sanfilippo wrote: > Sure, I will test this solution. But I think NETIF_F_FRAGLIST should also be > cleared in this case, right? Hmm, interesting question. I think only hns3 makes meaningful use of NETIF_F_FRAGLIST, right? I'm looking at hns3_fill_skb_to_desc(). Other drivers seem to set it for ridiculous reasons - looking at commit 66aa0678efc2 ("ibmveth: Support to enable LSO/CSO for Trunk VEA.") - they set NETIF_F_FRAGLIST and then linearize the skb chain anyway. The claimed 4x throughput benefit probably has to do with less skbs traversing the stack? I don't know. Anyway, it is hard to imagine all the things that could go wrong with chains of IP fragments on a DSA interface, precisely because I have so few examples to look at. I would say, header taggers are probably fine, tail taggers not so much, so apply the same treatment as for NETIF_F_SG?