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 A0CBBDF46 for ; Wed, 2 Aug 2023 12:30:15 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 3BE1868AA6; Wed, 2 Aug 2023 14:30:11 +0200 (CEST) Date: Wed, 2 Aug 2023 14:30:10 +0200 From: Christoph Hellwig To: Chaitanya Kulkarni Cc: Jeff Moyer , Christoph Hellwig , "dan.j.williams@intel.com" , "vishal.l.verma@intel.com" , "dave.jiang@intel.com" , "ira.weiny@intel.com" , "nvdimm@lists.linux.dev" , axboe@kernel.dk, linux-block@vger.kernel.org Subject: Re: [PATCH V2 1/1] pmem: set QUEUE_FLAG_NOWAIT Message-ID: <20230802123010.GB30792@lst.de> References: <20230731224617.8665-1-kch@nvidia.com> <20230731224617.8665-2-kch@nvidia.com> <20230801155943.GA13111@lst.de> <0a2d86d6-34a1-0c8d-389c-1dc2f886f108@nvidia.com> Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0a2d86d6-34a1-0c8d-389c-1dc2f886f108@nvidia.com> User-Agent: Mutt/1.5.17 (2007-11-01) Given that pmem simply loops over an arbitrarily large bio I think we also need a threshold for which to allow nowait I/O. While it won't block for giant I/Os, doing all of them in the submitter context isn't exactly the idea behind the nowait I/O. I'm not really sure what a good theshold would be, though. Btw, please also always add linux-block to the Cc list for block driver patches that are even the slightest bit about the block layer interface.