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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EDD01C433F5 for ; Thu, 5 May 2022 02:21:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=vNZRhYhBCDtC67TG4Z9aYLBI7cGcWFdf+2QPpSiEfR8=; b=LU866uB2/jFMcu X2OEW1Bp4Nv8YbNTzWTYQYuQ7jaqkrIAbxcZtjgyflDiIe2hWTeDm0zyxEBU3tRKu7TOYDLSsvvXE pDqbqU89xtZ2UTbd7TQc/6HfGrvUsfYkRCuS0/59k2jDNhbjeoVhMblW+Ko4AY3kmgeqxV3pNQi30 A1xiMeiy+HbOodNRhtflrXp4k1/Ksmq1GrQZixXsjJMZnnkw0Itag8opIzzzFQAl6TjTeoWL1ZtP9 7LGe82t+C1o1+PNSsO5FaAl8PBZbtULKfr618cDpgHlKkywixmQ2EPaH5DllUVXyShiYdYaX2ZzRx leL1yO2EZG1JBobriWuA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nmR6a-00DbMg-Dh; Thu, 05 May 2022 02:20:36 +0000 Received: from ams.source.kernel.org ([2604:1380:4601:e00::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nmR6X-00DbLS-AZ for linux-arm-kernel@lists.infradead.org; Thu, 05 May 2022 02:20:34 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id C20E7B82824; Thu, 5 May 2022 02:20:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 240E2C385A5; Thu, 5 May 2022 02:20:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1651717230; bh=4JuRqwNQ9hwhUqTttT0gUicftS+I9uLmhezFx58s+fo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=kB5vwBUbJlggf+csLOoIg92Angr/zA4Hb3vNbjMioqtV2/uR879da47d+Y38esAW/ J2kheQFTNgQivKUXK5NOZLhoXhGhegDwzAMYan/e3AuD1XDwPnUYKuOeIhGbMIJDiq pNuuNuRuOMBbPjbixs8f2Hw5oqOEsral2Jgq2UNgMeBOkypxbHwS2WIVEr3qMwoLc5 YnG8p7ADHMxGUVFaiCB7MO7A41BNfTfpZb3wrIfF3pUvl3T0kKxkiE7tiWnmCLtmGg TCykz182vzT96MPv0CosQYBR5gMSM16Q3LdY+lGr9E9y7thhRQ6QCYtJmKWm1W0keO 3WWttwF7xND9Q== Date: Wed, 4 May 2022 19:20:28 -0700 From: Jakub Kicinski To: Radhey Shyam Pandey , Robert Hancock Cc: "netdev@vger.kernel.org" , "davem@davemloft.net" , "edumazet@google.com" , "pabeni@redhat.com" , Michal Simek , "linux-arm-kernel@lists.infradead.org" , Harini Katakam Subject: Re: [PATCH net-next] net: axienet: Use NAPI for TX completion path Message-ID: <20220504192028.2f7d10fb@kernel.org> In-Reply-To: References: <20220429222835.3641895-1-robert.hancock@calian.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220504_192033_554654_3880EF02 X-CRM114-Status: GOOD ( 16.74 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, 2 May 2022 19:30:51 +0000 Radhey Shyam Pandey wrote: > > This driver was using the TX IRQ handler to perform all TX completion > > tasks. Under heavy TX network load, this can cause significant irqs-off > > latencies (found to be in the hundreds of microseconds using ftrace). > > This can cause other issues, such as overrunning serial UART FIFOs when > > using high baud rates with limited UART FIFO sizes. > > > > Switch to using the NAPI poll handler to perform the TX completion work > > to get this out of hard IRQ context and avoid the IRQ latency impact. > > Thanks for the patch. I assume for simulating heavy network load we > are using netperf/iperf. Do we have some details on the benchmark > before and after adding TX NAPI? I want to see the impact on > throughput. Seems like a reasonable ask, let's get the patch reposted with the numbers in the commit message. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel