Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 6 Feb 2001 13:19:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 6 Feb 2001 13:19:37 -0500 Received: from chiara.elte.hu ([157.181.150.200]:21770 "HELO chiara.elte.hu") by vger.kernel.org with SMTP id ; Tue, 6 Feb 2001 13:19:31 -0500 Date: Tue, 6 Feb 2001 19:18:51 +0100 (CET) From: Ingo Molnar Reply-To: To: Ben LaHaise Cc: "Stephen C. Tweedie" , Linus Torvalds , Alan Cox , Manfred Spraul , Steve Lord , Linux Kernel List , , Ingo Molnar Subject: Re: [Kiobuf-io-devel] RFC: Kernel mechanism: Compound event wait In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 6 Feb 2001, Ben LaHaise wrote: > Let me just emphasize what Stephen is pointing out: if requests are > properly merged at higher layers, then merging is neither required nor > desired. [...] this is just so incorrect that it's not funny anymore. - higher levels just do not have the kind of knowledge lower levels have. - merging decisions are often not even *deterministic*. - higher levels do not have the kind of state to eg. merge requests done by different users. The only chance for merging is often the lowest level, where we already know what disk, which sector. - merging is not even *required* for some devices - and chances are high that we'll get away from this inefficient and unreliable 'rotating array of disks' business of storing bulk data in this century. (solid state disks, holographic storage, whatever.) i'm truly shocked that you and Stephen are both saying this. Ingo - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/