From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 83E1945C75; Mon, 4 Nov 2024 10:16:48 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 5DAE4402AF; Mon, 4 Nov 2024 10:16:48 +0100 (CET) Received: from fout-b4-smtp.messagingengine.com (fout-b4-smtp.messagingengine.com [202.12.124.147]) by mails.dpdk.org (Postfix) with ESMTP id BA8B14021F for ; Mon, 4 Nov 2024 10:16:46 +0100 (CET) Received: from phl-compute-08.internal (phl-compute-08.phl.internal [10.202.2.48]) by mailfout.stl.internal (Postfix) with ESMTP id B6AB11140087; Mon, 4 Nov 2024 04:16:45 -0500 (EST) Received: from phl-mailfrontend-02 ([10.202.2.163]) by phl-compute-08.internal (MEProxy); Mon, 04 Nov 2024 04:16:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= cc:cc:content-transfer-encoding:content-type:content-type:date :date:from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to; s=fm3; t=1730711805; x=1730798205; bh=YG2/kqA/OdSXbD3itcFeGo2mIy3F0VFiovLyBR4hMCY=; b= 0QiQzWwi8hWiS5LcCCoSDz02f1/wJXpmGVT02xZk3t6tlN5hI72s/gGsuBkd+WWl BKT+WQNi7V3nIRBpaBNUZYUCeTu8vtLSRtUjHA8hEDPrUmVNoqNpiIubRX5rDHx9 hs06ey+QKVcOS8MyuvGjO3kj+ep+xf2z+A+4Gglohsom2NromoCZ1Z68Nok8xm97 QcBe7xdeHobr5XYBqdDE4J3bzWgWpsqXClpfPJw81lsIVE9vLyOSyAWuUmLDuwiO clCnrzoaPPEfSTnYU4gqFmSrkk4f0XVcxBBYlRchrDK+CRxI0dn3jrHq4XF803un xzlnkBivo8sB1Dji3pdE/Q== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:content-type:date:date:feedback-id:feedback-id :from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm3; t=1730711805; x= 1730798205; bh=YG2/kqA/OdSXbD3itcFeGo2mIy3F0VFiovLyBR4hMCY=; b=M y2gRlzwzyE09nf90cKZJktn6sZfqnxu4PLGuj7rwr1RVrJzGh2Ytb923L+PvcF/h b5/leicxasMZo4SiCa/PuN1ZmH+EaKaJWhBKrAYV440WX6C4EzOfQdcmwqyPljW3 3kiMr2T5qtOXU4L+sGT47ipiAIOe8sdvLm/ami1dq5RUSJJFlZ2NGc1EITGl7ElF ZGwkc1XpB26VqCg0wK1SYmlmXAPzJsY3OIUDAOIWq9QUHbZkahMljSWSuzMBaXPZ DPCBtCoOOTiRQdrd9wVxBFjHRZxeK9BvcwPjjADLcOrHqqYeRB7wGd4afQedZzgw 4ZFLVUcwnA2hIqpAn2vpw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeeftddrvdeliedgtdduucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdggtfgfnhhsuhgsshgtrhhisggvpdfu rfetoffkrfgpnffqhgenuceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnh htshculddquddttddmnecujfgurhephffvvefufffkjghfggfgtgesthfuredttddtjeen ucfhrhhomhepvfhhohhmrghsucfoohhnjhgrlhhonhcuoehthhhomhgrshesmhhonhhjrg hlohhnrdhnvghtqeenucggtffrrghtthgvrhhnpeejudevheeiveduuddtveffgfdtgeek ueevjeffjeegtdeggeekgfdvuefgfeekjeenucevlhhushhtvghrufhiiigvpedtnecurf grrhgrmhepmhgrihhlfhhrohhmpehthhhomhgrshesmhhonhhjrghlohhnrdhnvghtpdhn sggprhgtphhtthhopeduuddpmhhouggvpehsmhhtphhouhhtpdhrtghpthhtohepghgrvh hinhhlsehnvhhiughirgdrtghomhdprhgtphhtthhopehsthgvphhhvghnsehnvghtfiho rhhkphhluhhmsggvrhdrohhrghdprhgtphhtthhopehvihgrtghhvghslhgrvhhosehnvh hiughirgdrtghomhdprhgtphhtthhopeguvghvseguphgukhdrohhrghdprhgtphhtthho pehmrghtrghnsehnvhhiughirgdrtghomhdprhgtphhtthhopehorhhikhgrsehnvhhiug hirgdrtghomhdprhgtphhtthhopegushhoshhnohifshhkihesnhhvihguihgrrdgtohhm pdhrtghpthhtohepsghinhhgiiesnhhvihguihgrrdgtohhmpdhrtghpthhtohepshhurg hnmhhinhhgmhesnhhvihguihgrrdgtohhm X-ME-Proxy: Feedback-ID: i47234305:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Mon, 4 Nov 2024 04:16:43 -0500 (EST) From: Thomas Monjalon To: "Minggang(Gavin) Li" , Stephen Hemminger , Slava Ovsiienko Cc: "dev@dpdk.org" , Matan Azrad , Ori Kam , Dariusz Sosnowski , Bing Zhao , Suanming Mou , Raslan Darawsheh , rongwei liu Subject: Re: [PATCH V3 3/7] net/mlx5: add new devargs to control probe optimization Date: Mon, 04 Nov 2024 10:16:42 +0100 Message-ID: <1964706.h4nFI6E9mP@thomas> In-Reply-To: References: <20241028091822.860660-8-gavinl@nvidia.com> <2873618.Nya5fj1elA@thomas> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org 04/11/2024 09:36, Slava Ovsiienko: > From: Thomas Monjalon > > 29/10/2024 17:20, Stephen Hemminger: > > > On Tue, 29 Oct 2024 15:42:52 +0200 > > > "Minggang Li(Gavin)" wrote: > > > > > > > From: Rongwei Liu > > > > > > > > Add a new devarg probe_opt_en to control probe optimization in PMD. > > > > > > > > By default, the value is 0 and no behavior changed. > > > > > > > > Signed-off-by: Rongwei Liu > > > > Acked-by: Viacheslav Ovsiienko > > > > > > Once again, every option you introduce expands the test space by 2X. > > > "Do or Do not. There is no try" > > > Either it works all the time or it is a bad idea. > > > > I fully agree. > > We should not merge this series before providing a good answer, or making > > it automatic. > > > > One more thing: a commit log should always explain "why". > > Here it should say why it is not automatic. > > Is there a good reason to disable this feature? > > The feature is event-driven and depends on the system/DPDK environment. > Example: > - DPDK handles interrupts in the single dedicated EAL thread > - the failsafe PMD in "interrupt" handler performs device probe() action, > that might take a long time and DPDK event/interrupt handle experiences the > significant delays, sometime causing the malfunction. > > Another concern - Netlink buffers have limited capacity, and with high message > rate might be overflown. > > This is just the examples, sure, most of the time feature works reliably. > The feature is needed for few users only, that's why we follow conservative > approach. Do you think we should put all the stuff above in the commit log? Yes the reasoning must be explained in the commit log. And the user documentation must explained clearly when to use it or not. But honestly, I feel it would be better to make sure it works always and avoid the option.