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 F39EF1922D5; Wed, 5 Jun 2024 07:27:46 +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=1717572468; cv=none; b=BSw16IcKCYF6A5NoZ7b5jhTdO9YbheKH1d7N2nqtXYA3X1Rva5FAP5HaeV1Vat1+PCK4itOzSJ2Sg44IgAWHZaZOyUnOE6G5BkwveyOhS8U4FnD40t0Dz++N0fy480AvzymCz2xnsO5N62Jxf9JbrFm35yQ5ammapVLV74t9ZVw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717572468; c=relaxed/simple; bh=8LUykD/62bGMRfd/a9I1PHICud17UdPvZyyzW9ay8wM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pn/Htn1V3OYFJanM6koYswBZ4zfYlgJIBfwMO5vOnc+SeGNUA/1O87FIEOq8YupWJCpSOYCmZw/l9np/oTWFwjuhrbh4TDPKuzTOC7B2Kb0XiEkWuvPXTOLcqm5ySkpBl/ZGOItdlfn+HhEc0W1Fi5vDGnB/ERb1JIuPHlR0248= 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 6002E68D0D; Wed, 5 Jun 2024 09:27:43 +0200 (CEST) Date: Wed, 5 Jun 2024 09:27:42 +0200 From: Christoph Hellwig To: Jakub Kicinski Cc: Christoph Hellwig , Ofir Gal , davem@davemloft.net, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, netdev@vger.kernel.org, ceph-devel@vger.kernel.org, dhowells@redhat.com, edumazet@google.com, pabeni@redhat.com, kbusch@kernel.org, axboe@kernel.dk, sagi@grimberg.me, philipp.reisner@linbit.com, lars.ellenberg@linbit.com, christoph.boehmwalder@linbit.com, idryomov@gmail.com, xiubli@redhat.com Subject: Re: [PATCH v2 0/4] bugfix: Introduce sendpages_ok() to check sendpage_ok() on contiguous pages Message-ID: <20240605072742.GA16306@lst.de> References: <20240530142417.146696-1-ofir.gal@volumez.com> <20240531073214.GA19108@lst.de> <20240601153610.30a92740@kernel.org> <20240604043041.GA28886@lst.de> <20240604074224.44668dab@kernel.org> Precedence: bulk X-Mailing-List: netdev@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: <20240604074224.44668dab@kernel.org> User-Agent: Mutt/1.5.17 (2007-11-01) On Tue, Jun 04, 2024 at 07:42:24AM -0700, Jakub Kicinski wrote: > I'd guess the thinking was that if we push back the callers would > switch the relevant allocations to be page-backed. But we can add > a comment above the helper that says "you'd be better off using > page frags and calling sendmsg(MSG_SPLICE_PAGES) directly". That's just not how network block devices or file systems work, they don't control the allocations and need to take what gets fed to them.