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 4F2FBC48260 for ; Fri, 16 Feb 2024 09:49:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=U/aZOeDnFL01hyfR2OWfnC1Uprj0z5woI9XMPol02CU=; b=U2gKI7QvpdxvJWd0NZGUpj3W+x ECp7KuTUkXU94K7QpPuTlAt467+ormPxlxbmb8p2FBxFLd+mAMivH2UKOIyCloz7fLbH7tYjMmFck ITBHP6mSp7jJ9H5J9xSzpIbXF7RLryBno3CV71THpvIqtTczR2SBW/ZFdnjbXivXi7Dq3fgubaNpP nYpbWCUWYBkmG510DjjSNwwd3TMirPRLm3qtI2UNfKdyYgbx8uQ2bLnXMomIjLZLyHNCV+P8qwBRU S0DwfIg48IwVCsYMTv7qSvDpn8pdIubN9KPFN9ZeEP9PlhrUdJsAW1dPMt36PHn/EHaZFBgShecyY yj6WOEXQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rauqT-00000001myK-2MUm; Fri, 16 Feb 2024 09:49:25 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rauqQ-00000001mxT-2aYH for linux-nvme@lists.infradead.org; Fri, 16 Feb 2024 09:49:24 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 1585968BFE; Fri, 16 Feb 2024 10:49:10 +0100 (CET) Date: Fri, 16 Feb 2024 10:49:09 +0100 From: Christoph Hellwig To: Daniel Wagner Cc: James Smart , Keith Busch , Christoph Hellwig , Sagi Grimberg , Hannes Reinecke , linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v0 1/6] nvme-fabrics: introduce connect_sync option Message-ID: <20240216094909.GA19961@lst.de> References: <20240216084526.14133-1-dwagner@suse.de> <20240216084526.14133-2-dwagner@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240216084526.14133-2-dwagner@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240216_014922_828632_F040C23C X-CRM114-Status: GOOD ( 15.74 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Fri, Feb 16, 2024 at 09:45:21AM +0100, Daniel Wagner wrote: > The TCP and RDMA transport are doing a synchronous connect, meaning the > syscal returns with the final result, that is. it either failed or > succeeded. > > This isn't the case for FC. This transport just setups and triggers > the connect and returns without waiting on the result. That's really weird and unexpected. James, can you explain the reason behind this? > Introduce a flag > to allow user space to control the behavior, wait or don't wait. I'd expect this to be the default, but I'll wait to hear more about the rationale. If we keep the async default the option looks sensible.