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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EEF50C3DA78 for ; Tue, 17 Jan 2023 19:56:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232973AbjAQT4k (ORCPT ); Tue, 17 Jan 2023 14:56:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41154 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235146AbjAQTyM (ORCPT ); Tue, 17 Jan 2023 14:54:12 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 311AE74973 for ; Tue, 17 Jan 2023 10:48:53 -0800 (PST) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 5E5606130C for ; Tue, 17 Jan 2023 18:48:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6FDD7C433D2; Tue, 17 Jan 2023 18:48:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673981332; bh=23MZApzNDTDFAty151R9reJt82K4UjNpjmNHeiL0IX8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=FdOXwiR4KcSUUH+E7bVORDg/KguL/G6+h+lCfW/duprI4Jgs58A6Mdo9UVfSZHtOf H/H4RgD3umkxn3TiSoGPBliTlk8KjRTLTYYoINb7eF2IYjoHwQLl6w+JyG7uSgHZBw 1LnSK+kmUkseos1aImEnt+V0P8+VC6GNunqX9iMDTRr4MTEuV0ZRVGXiGup9eUJDqf qWWifJLff+uJnq5LrpjVfXmXF/g3CmMrLP1GFXr72Yj0T9L5rPs5oszB2KWsR/zJ85 fyJA2XD+gPHUemw9p5lP28khwEnk//Bgj6iZy6Frr9FVC7xVKlQPpyns+xRton6qXg qb2xugy4yXpGQ== Date: Tue, 17 Jan 2023 10:48:51 -0800 From: Jakub Kicinski To: Gal Pressman Cc: Saeed Mahameed , "David S. Miller" , Paolo Abeni , Eric Dumazet , Saeed Mahameed , netdev@vger.kernel.org, Tariq Toukan Subject: Re: [net-next 08/15] net/mlx5e: Add hairpin debugfs files Message-ID: <20230117104851.2c722c6e@kernel.org> In-Reply-To: References: <20230111053045.413133-1-saeed@kernel.org> <20230111053045.413133-9-saeed@kernel.org> <20230111103422.102265b3@kernel.org> <20230111130342.6cef77d7@kernel.org> <20230111194608.7f15b9a1@kernel.org> <20230112142049.211d897b@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sun, 15 Jan 2023 12:04:58 +0200 Gal Pressman wrote: > The hairpin queues are different than other queues in the driver as they > are controlled by the device (refill, completion handling, etc.). > Hardware configuration can make a difference in performance when working > with hairpin, things that wouldn't necessarily affect regular queues the > driver uses. The debugging process is also more difficult as the driver > has little control/visibility over these. > > At the end of the day, the debug process *is* going to be playing with > the queue size/number, this allows us to potentially find a number that > releases the bottleneck and see how it affects other stages in the pipe. > Since these cases are unlikely to happen, and changing of these > parameters can affect the device in other ways, we don't want people to > just increase them when they encounter performance issues, especially > not in production environments. > > Does that make sense? Okay, I think my guess that "debug" here means "wobble it to see if the device can go faster" was indeed correct. Long term maybe we should find a better word for that than "debug".