Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753960Ab1BDJWE (ORCPT ); Fri, 4 Feb 2011 04:22:04 -0500 Received: from mxs.selfip.ru ([77.221.143.26]:49848 "EHLO mxs.selfmail.ru" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753622Ab1BDJWB (ORCPT ); Fri, 4 Feb 2011 04:22:01 -0500 X-ACL-SPF: Subject: Re: [Xen-devel] [PATCH R3 0/7] xen/balloon: Memory hotplug support for Xen balloon driver From: Vasiliy G Tolstov Reply-To: v.tolstov@selfip.ru To: Ian Campbell Cc: Daniel Kiper , "akpm@linux-foundation.org" , "andi.kleen@intel.com" , "haicheng.li@linux.intel.com" , "fengguang.wu@intel.com" , "jeremy@goop.org" , "konrad.wilk@oracle.com" , Dan Magenheimer , "pasik@iki.fi" , "dave@linux.vnet.ibm.com" , "wdauchy@gmail.com" , "rientjes@google.com" , "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" In-Reply-To: <1296810682.13091.571.camel@zakaz.uk.xensource.com> References: <20110203162345.GC1364@router-fw-old.local.net-space.pl> <1296768009.2346.7.camel@mobile> <1296810682.13091.571.camel@zakaz.uk.xensource.com> Content-Type: text/plain; charset="UTF-8" Organization: Selfip.Ru Date: Fri, 04 Feb 2011 12:21:32 +0300 Message-ID: <1296811292.8588.3.camel@vase> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 Content-Transfer-Encoding: 7bit X-ACL-DATA: Invalid Message-Id Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1475 Lines: 33 On Fri, 2011-02-04 at 09:11 +0000, Ian Campbell wrote: > On Thu, 2011-02-03 at 21:20 +0000, Vasiliy G Tolstov wrote: > > I have some may be offtopic question: Is that possible to export balloon > > function balloon_set_new_target to GPL modules (EXPORT_SYMBOL_GPL) ? > > This helps to kernel modules (not in kernel tree) to contol balloonin > > (for example autoballoon or something else) without needing to write so > > sysfs. (Writing files from kernel module is bad, this says Linux Kernel > > Faq). > > Is there a reason to do it from kernel space in the first place? auto > ballooning can be done by a userspace daemon, can't it? > > Ian. > Yes. It can be done via userspace, but if i want to control autoballon via sysfs/sysctl/procfs i need to write module. And i don't think that export this function can break some stuff. Now i have autoballoon kernel module that enlarge and shrinks memory. Userspace daemon need some dependencies like glibc, libxenstore and others, but if i'm not provide ability to chouse kernel (i'm boot domU via kernel and ramdisk), very simple to add in ramdisk kernel module that says disk/memory usage and controls memory ballooning. -- Vasiliy G Tolstov Selfip.Ru -- 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/