From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (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 1AB1A1B959 for ; Fri, 16 Feb 2024 09:49:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.95.11.211 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708076964; cv=none; b=TzulwTe/jY9C0Oeo3hYdGPxApbHmpuPpbao2+JM/9md8KJtXCKCNBR5cE1p/VEpVDBl4NSvvm4uvuix2sQhgr91WcwftMHyyRmljnATZY3Ay7hqN1VMNQW04cENTaqf/9z771Q0xmnGokpKF3VPwH8AWzfYkKwzaZp227BTg+BQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708076964; c=relaxed/simple; bh=SX3rfEZ2V/LrYP8qAfhIuKY32PglZ6mFq7UDcr04PwI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qK3HBflgejn/O/OUzHuC3+k6joTToc0Blc2eh1jYGT4ZpFu9hiFzGr0Juc2ZKmrAzteGKRsTjJhRzheHRcUzdltlvlHx6e+Ji/dITysTA9qGVENQunQFes1mQBpjAe/M33/bH643kKpbxtNHsrIdjmxK2y+u4pVlLmLfVCjquso= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de; spf=pass smtp.mailfrom=lst.de; arc=none smtp.client-ip=213.95.11.211 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lst.de 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> 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=us-ascii Content-Disposition: inline In-Reply-To: <20240216084526.14133-2-dwagner@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) 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.