Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933423AbXBETiG (ORCPT ); Mon, 5 Feb 2007 14:38:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933420AbXBETiG (ORCPT ); Mon, 5 Feb 2007 14:38:06 -0500 Received: from x35.xmailserver.org ([64.71.152.41]:4080 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933424AbXBETiF (ORCPT ); Mon, 5 Feb 2007 14:38:05 -0500 X-AuthUser: davidel@xmailserver.org Date: Mon, 5 Feb 2007 11:38:01 -0800 (PST) From: Davide Libenzi X-X-Sender: davide@alien.or.mcafeemobile.com To: Zach Brown cc: Ingo Molnar , Linus Torvalds , Linux Kernel Mailing List , linux-aio@kvack.org, Suparna Bhattacharya , Benjamin LaHaise Subject: Re: [PATCH 2 of 4] Introduce i386 fibril scheduling In-Reply-To: Message-ID: References: <20070201083611.GC18233@elte.hu> <20070202104900.GA13941@elte.hu> <20070202222110.GA1212@elte.hu> <87DE673C-92A0-4401-8DE5-BDC2C08B5F41@oracle.com> X-GPG-FINGRPRINT: CFAE 5BEE FD36 F65E E640 56FE 0974 BF23 270F 474E X-GPG-PUBLIC_KEY: http://www.xmailserver.org/davidel.asc 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 Content-Length: 1210 Lines: 30 On Mon, 5 Feb 2007, Zach Brown wrote: > > Or we need some sort of enter_context()/leave_context() (adopt mm, files, > > ...) to have a per-CPU kthread to be able to execute the syscall from the > > async() caller context. > > I believe that's what Ingo is hoping for, yes. Ok, but then we should ask ourselves if it's really worth to have a per-CPU pool (that will require quite a few changes to the current way of doing things), or a per-process pool (that would basically work as is). What advantage gives us a per-CPU pool? Setup cost? Not really IMO. Thread creation is pretty cheap, and a typical process using async will have a pretty huge lifespan (compared to the pool creation cost). Configurability scores for a per-process pool, because it may allow each process (eventually) to size his own. What's the real point in favour of a per-CPU pool, that justify all the changes that will have to be done in order to adopt such concept? - Davide - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/