From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx109.postini.com [74.125.245.109]) by kanga.kvack.org (Postfix) with SMTP id BA6D96B00F3 for ; Thu, 10 May 2012 11:19:48 -0400 (EDT) Received: by dakp5 with SMTP id p5so2543231dak.14 for ; Thu, 10 May 2012 08:19:47 -0700 (PDT) Date: Fri, 11 May 2012 00:19:37 +0900 From: Minchan Kim Subject: Re: [PATCH 3/4] zsmalloc use zs_handle instead of void * Message-ID: <20120510151937.GC2394@barrios> References: <1336027242-372-1-git-send-email-minchan@kernel.org> <1336027242-372-3-git-send-email-minchan@kernel.org> <4FA28907.9020300@vflare.org> <4FA2A2F0.3030509@linux.vnet.ibm.com> <4FA33DF6.8060107@kernel.org> <20120509201918.GA7288@kroah.com> <4FAB21E7.7020703@kernel.org> <20120510140215.GC26152@phenom.dumpdata.com> <4FABD503.4030808@vflare.org> <4FABDA9F.1000105@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4FABDA9F.1000105@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Seth Jennings Cc: Nitin Gupta , Konrad Rzeszutek Wilk , Minchan Kim , Greg Kroah-Hartman , Dan Magenheimer , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Thu, May 10, 2012 at 10:11:27AM -0500, Seth Jennings wrote: > On 05/10/2012 09:47 AM, Nitin Gupta wrote: > > > On 5/10/12 10:02 AM, Konrad Rzeszutek Wilk wrote: > >> struct zs { > >> void *ptr; > >> }; > >> > >> And pass that structure around? > >> > > > > A minor problem is that we store this handle value in a radix tree node. > > If we wrap it as a struct, then we will not be able to store it directly > > in the node -- the node will have to point to a 'struct zs'. This will > > unnecessarily waste sizeof(void *) for every object stored. > > > I don't think so. You can use the fact that for a struct zs var, &var > and &var->ptr are the same. > > For the structure above: > > void * zs_to_void(struct zs *p) { return p->ptr; } > struct zs * void_to_zs(void *p) { return (struct zs *)p; } > > Right? I though this, too but didn't tried it. We DO REALLY want it? Why should zsmalloc support like such strange interface? I want to solve the problem in zcache, not with zsmalloc. > > -- > Seth > -- 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