Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757114AbZDOW5U (ORCPT ); Wed, 15 Apr 2009 18:57:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753682AbZDOW5G (ORCPT ); Wed, 15 Apr 2009 18:57:06 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:50375 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753395AbZDOW5D (ORCPT ); Wed, 15 Apr 2009 18:57:03 -0400 Date: Wed, 15 Apr 2009 15:50:58 -0700 From: Andrew Morton To: Izik Eidus Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, avi@redhat.com, aarcange@redhat.com, chrisw@redhat.com, mtosatti@redhat.com, hugh@veritas.com, kamezawa.hiroyu@jp.fujitsu.com Subject: Re: [PATCH 4/4] add ksm kernel shared memory driver. Message-Id: <20090415155058.9e4635b2.akpm@linux-foundation.org> In-Reply-To: <49E661A5.8050305@redhat.com> References: <1239249521-5013-1-git-send-email-ieidus@redhat.com> <1239249521-5013-2-git-send-email-ieidus@redhat.com> <1239249521-5013-3-git-send-email-ieidus@redhat.com> <1239249521-5013-4-git-send-email-ieidus@redhat.com> <1239249521-5013-5-git-send-email-ieidus@redhat.com> <20090414150929.174a9b25.akpm@linux-foundation.org> <49E661A5.8050305@redhat.com> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1341 Lines: 35 On Thu, 16 Apr 2009 01:37:25 +0300 Izik Eidus wrote: > Andrew Morton wrote: > > On Thu, 9 Apr 2009 06:58:41 +0300 > > Izik Eidus wrote: > > > > > > > > Confused. In the covering email you indicated that v2 of the patchset > > had abandoned ioctls and had moved the interface to sysfs. > > > We have abandoned the ioctls that control the ksm behavior (how much cpu > it take, how much kernel pages it may allocate and so on...) > But we still use ioctls to register the application memory to be used > with ksm. hm. ioctls make kernel people weep and gnash teeth. An appropriate interface would be to add new syscalls. But as ksm is an optional thing and can even be modprobed, that doesn't work. And having a driver in mm/ which can be modprobed is kinda neat. I can't immediately think of a nicer interface. You could always poke numbers into some pseudo-file but to me that seems as ugly, or uglier than an ioctl (others seem to disagee). Ho hum. Please design the ioctl interface so that it doesn't need any compat handling if poss. -- 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/