Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753069Ab0D0MzS (ORCPT ); Tue, 27 Apr 2010 08:55:18 -0400 Received: from ksp.mff.cuni.cz ([195.113.26.206]:52214 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752582Ab0D0MzO (ORCPT ); Tue, 27 Apr 2010 08:55:14 -0400 Date: Tue, 27 Apr 2010 14:55:03 +0200 From: Pavel Machek To: Dan Magenheimer Cc: Avi Kivity , linux-kernel@vger.kernel.org, linux-mm@kvack.org, jeremy@goop.org, hugh.dickins@tiscali.co.uk, ngupta@vflare.org, JBeulich@novell.com, chris.mason@oracle.com, kurt.hackel@oracle.com, dave.mccracken@oracle.com, npiggin@suse.de, akpm@linux-foundation.org, riel@redhat.com Subject: Re: Frontswap [PATCH 0/4] (was Transcendent Memory): overview Message-ID: <20100427125502.GA3681@ucw.cz> References: <53c81c97-b30f-4081-91a1-7cef1879c6fa@default> <4BD07594.9080905@redhat.com> <4BD16D09.2030803@redhat.com> <4BD1A74A.2050003@redhat.com> <4830bd20-77b7-46c8-994b-8b4fa9a79d27@default> <4BD1B427.9010905@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1292 Lines: 31 Hi! > > Can we extend it? Adding new APIs is easy, but harder to maintain in > > the long term. > > Umm... I think the difference between a "new" API and extending > an existing one here is a choice of semantics. As designed, frontswap > is an extremely simple, only-very-slightly-intrusive set of hooks that > allows swap pages to, under some conditions, go to pseudo-RAM instead ... > "Extending" the existing swap API, which has largely been untouched for > many years, seems like a significantly more complex and error-prone > undertaking that will affect nearly all Linux users with a likely long > bug tail. And, by the way, there is no existence proof that it > will be useful. > Seems like a no-brainer to me. Stop right here. Instead of improving existing swap api, you just create one because it is less work. We do not want apis to cummulate; please just fix the existing one. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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/