From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id 1AD2A8D0039 for ; Fri, 4 Feb 2011 04:24:20 -0500 (EST) 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 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" Date: Fri, 04 Feb 2011 12:21:32 +0300 Message-ID: <1296811292.8588.3.camel@vase> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: 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" 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org