From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 26 Aug 2001 15:31:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 26 Aug 2001 15:31:09 -0400 Received: from islay.mach.uni-karlsruhe.de ([129.13.162.92]:42933 "EHLO mailout.plan9.de") by vger.kernel.org with ESMTP id ; Sun, 26 Aug 2001 15:31:01 -0400 Date: Sun, 26 Aug 2001 21:31:16 +0200 From: To: Daniel Phillips Cc: Rik van Riel , Roger Larsson , linux-kernel@vger.kernel.org Subject: Re: [resent PATCH] Re: very slow parallel read performance Message-ID: <20010826213116.E2994@cerebro.laendle> Mail-Followup-To: Daniel Phillips , Rik van Riel , Roger Larsson , linux-kernel@vger.kernel.org In-Reply-To: <20010824201125Z16096-32383+1213@humbolt.nl.linux.org> <20010825012338.B547@cerebro.laendle> <20010826164818Z16191-32383+1474@humbolt.nl.linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20010826164818Z16191-32383+1474@humbolt.nl.linux.org> X-Operating-System: Linux version 2.4.8-ac8 (root@cerebro) (gcc version 3.0.1) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Aug 26, 2001 at 06:54:55PM +0200, Daniel Phillips wrote: > But it's a very interesting idea: instead of performing readahead in > generic_file_read the user thread would calculate the readahead window More basic, less interesting but far more useful would be real aio, sicne this would get rid of hundreds of threads that need manual killing when the server crashes during development and keep the accept socket open ;) (But it seems we will have sth. like that in 2.6, so I am generally happy ;) > submit. The user thread benefits by avoiding some stalls due to > readahead->readpage, as well as avoiding thrashing due to excessive > readahead. In an ideal world, I would not need user buffers as well and could just tell the kernel "copy from file to network", but that requires too much kernel tinkery I believe (although, when there is generic aio in the kernel there might some day be a aio_sendfile ;) -- -----==- | ----==-- _ | ---==---(_)__ __ ____ __ Marc Lehmann +-- --==---/ / _ \/ // /\ \/ / pcg@goof.com |e| -=====/_/_//_/\_,_/ /_/\_\ XX11-RIPE --+ The choice of a GNU generation | |