From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754299AbaIVPt0 (ORCPT ); Mon, 22 Sep 2014 11:49:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50252 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751070AbaIVPtX (ORCPT ); Mon, 22 Sep 2014 11:49:23 -0400 From: Jeff Moyer To: Christoph Hellwig Cc: "Elliott\, Robert \(Server Storage\)" , Andreas Dilger , Milosz Tanski , "linux-kernel\@vger.kernel.org" , "linux-fsdevel\@vger.kernel.org" , "linux-aio\@kvack.org" , Mel Gorman , Volker Lendecke , Tejun Heo Subject: Re: [RFC PATCH 0/7] Non-blockling buffered fs read (page cache only) References: <8EC2A7F3-0E25-4054-9863-4488B8ED5C8D@dilger.ca> <94D0CD8314A33A4D9D801C0FE68B402958C81D56@G9W0745.americas.hpqcorp.net> <20140919112147.GA4639@infradead.org> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 X-PCLoadLetter: What the f**k does that mean? Date: Mon, 22 Sep 2014 11:48:35 -0400 In-Reply-To: <20140919112147.GA4639@infradead.org> (Christoph Hellwig's message of "Fri, 19 Sep 2014 04:21:47 -0700") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christoph Hellwig writes: > Without the atomic WRITE SCATTERED use case adding the syscalls seems > rather pointless, and I'd really avoid blocking nice software only > features like the per-I/O nonblock flag (and the similarly trivial > per-I/O sync option I have a prototype for) on it. Andreas and Zach pointed out that the scatter/gather system calls also help network file systems. I'm not yet sure how much work it would be, but it certainly seems worth considering readx/writex (or whatever we want to call them) to avoid needlessly adding a ton of system calls. Cheers, Jeff