Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759937Ab2EJPMF (ORCPT ); Thu, 10 May 2012 11:12:05 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:50884 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758283Ab2EJPMC (ORCPT ); Thu, 10 May 2012 11:12:02 -0400 Message-ID: <4FABDA9F.1000105@linux.vnet.ibm.com> Date: Thu, 10 May 2012 10:11:27 -0500 From: Seth Jennings User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Nitin Gupta CC: Konrad Rzeszutek Wilk , Minchan Kim , Greg Kroah-Hartman , Dan Magenheimer , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 3/4] zsmalloc use zs_handle instead of void * 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> In-Reply-To: <4FABD503.4030808@vflare.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12051015-2398-0000-0000-0000068782E3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 964 Lines: 34 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? -- Seth -- 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/