From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from vps0.lunn.ch (vps0.lunn.ch [156.67.10.101]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BD10F27F17D; Tue, 6 May 2025 12:10:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=156.67.10.101 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746533418; cv=none; b=NOa0UBWKG0dD+j3LZwOsPKuFime2trl03lPemCEiSu+mzkUMaBhDeY9Ouu+R3eDIzYiYwe5t+L87GMUsfJ/aTy+SCnNe9aAdLbmtKAUKgtWShD1QduYcN5QqIi+7EyJJ6rpA3NRBWczpyK5Nb/HHO8ijHkq6PJXX7II2pm/atzQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746533418; c=relaxed/simple; bh=TfGf41BI+CEpoOqGEKh3oXOKY+QC+CgLE8Pee51SleQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=eJ2fLGqujDjc+3F4TU8V7Wp4OXnk7dATo2qViDmWI8LywNjDQ3Ea51N0yrWr+OYsjG6CCru3QeJyUr8G8LrtLVEolyZ5qE+By1i+yxiI0x7MqzwMu8/Oxz51picBNrMosciiFXppCEborv9jcEDRH1rWDzo8gsqqTjZMkTjYN0g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch; spf=pass smtp.mailfrom=lunn.ch; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b=me/MwPh3; arc=none smtp.client-ip=156.67.10.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lunn.ch Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="me/MwPh3" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Transfer-Encoding:Content-Disposition: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:From: Sender:Reply-To:Subject:Date:Message-ID:To:Cc:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Content-Disposition: In-Reply-To:References; bh=LjFg4NzOfHgj1oyywetZuH3fvyYFzX5T7Wr9eejsvHY=; b=me /MwPh3urNw/U+weqBX9npRAbNuLn2pVCx5lAmrjCRsvWkQ9hmAV/0A6/YuglFD2cFELRrL/jtrpyq TNa9qwVfzmUl48jPFAZXyfT4TGNqlcs00lW94ouJBvKQ29uuDhIdWN4KfnKRXvg2rXuRLgxoCBbvd Z2EcZmCZd31OYO4=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1uCH7h-00Bksz-7V; Tue, 06 May 2025 14:10:09 +0200 Date: Tue, 6 May 2025 14:10:09 +0200 From: Andrew Lunn To: Thangaraj.S@microchip.com Cc: Bryan.Whitehead@microchip.com, andrew+netdev@lunn.ch, davem@davemloft.net, linux-kernel@vger.kernel.org, pabeni@redhat.com, kuba@kernel.org, edumazet@google.com, netdev@vger.kernel.org, UNGLinuxDriver@microchip.com Subject: Re: [PATCH v1 net-next] net: lan743x: configure interrupt moderation timers based on speed Message-ID: References: <20250505072943.123943-1-thangaraj.s@microchip.com> <42768d74fc73cd3409f9cdd5c5c872747c2d7216.camel@microchip.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <42768d74fc73cd3409f9cdd5c5c872747c2d7216.camel@microchip.com> On Tue, May 06, 2025 at 04:02:30AM +0000, Thangaraj.S@microchip.com wrote: > Hi Andrew, > Thanks for reviewing the patch, > > On Mon, 2025-05-05 at 14:15 +0200, Andrew Lunn wrote: > > EXTERNAL EMAIL: Do not click links or open attachments unless you > > know the content is safe > > > > On Mon, May 05, 2025 at 12:59:43PM +0530, Thangaraj Samynathan wrote: > > > Configures the interrupt moderation timer value to 64us for 2.5G, > > > 150us for 1G, 330us for 10/100M. Earlier this was 400us for all > > > speeds. This improvess UDP TX and Bidirectional performance to > > > 2.3Gbps from 1.4Gbps in 2.5G. These values are derived after > > > experimenting with different values. > > > > It would be good to also implement: > > > > ethtool -c|--show-coalesce devname > > > > ethtool -C|--coalesce devname [adaptive-rx on|off] [adaptive- > > tx on|off] > > [rx-usecs N] [rx-frames N] [rx-usecs-irq N] [rx-frames- > > irq N] > > [tx-usecs N] [tx-frames N] [tx-usecs-irq N] [tx-frames- > > irq N] > > [stats-block-usecs N] [pkt-rate-low N] [rx-usecs-low N] > > [rx-frames-low N] [tx-usecs-low N] [tx-frames-low N] > > [pkt-rate-high N] [rx-usecs-high N] [rx-frames-high N] > > [tx-usecs-high N] [tx-frames-high N] [sample-interval > > N] > > [cqe-mode-rx on|off] [cqe-mode-tx on|off] [tx-aggr-max- > > bytes N] > > [tx-aggr-max-frames N] [tx-aggr-time-usecs N] > > > > so the user can configure it. Sometimes lower power is more important > > than high speed. > > > > Andrew > > We've tuned the interrupt moderation values based on testing to improve > performance. For now, we’ll keep these fixed values optimized for > performance across all speeds. That said, we agree that adding ethtool > -c/-C support would provide valuable flexibility for users to balance > power and performance, and we’ll consider implementing that in a future > update. As you said, you have optimised for performance. That might cause regressions for some users. We try to avoid regressions, and if somebody does report a regression, we will have to revert this change. If you were to implement this ethtool option, we are a lot less likely to make a revert, we can instruct the user how to set the coalesce for there use case. Andrew