Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756320Ab2EJOIt (ORCPT ); Thu, 10 May 2012 10:08:49 -0400 Received: from rcsinet15.oracle.com ([148.87.113.117]:18775 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759597Ab2EJOIq (ORCPT ); Thu, 10 May 2012 10:08:46 -0400 Date: Thu, 10 May 2012 10:02:15 -0400 From: Konrad Rzeszutek Wilk To: Minchan Kim Cc: Greg Kroah-Hartman , Seth Jennings , Nitin Gupta , 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 * Message-ID: <20120510140215.GC26152@phenom.dumpdata.com> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4FAB21E7.7020703@kernel.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2490 Lines: 70 On Thu, May 10, 2012 at 11:03:19AM +0900, Minchan Kim wrote: > On 05/10/2012 05:19 AM, Greg Kroah-Hartman wrote: > > > On Fri, May 04, 2012 at 11:24:54AM +0900, Minchan Kim wrote: > >> On 05/04/2012 12:23 AM, Seth Jennings wrote: > >> > >>> On 05/03/2012 08:32 AM, Nitin Gupta wrote: > >>> > >>>> On 5/3/12 2:40 AM, Minchan Kim wrote: > >>>>> We should use zs_handle instead of void * to avoid any > >>>>> confusion. Without this, users may just treat zs_malloc return value as > >>>>> a pointer and try to deference it. > >>>>> > >>>>> Cc: Dan Magenheimer > >>>>> Cc: Konrad Rzeszutek Wilk > >>>>> Signed-off-by: Minchan Kim > >>>>> --- > >>>>> drivers/staging/zcache/zcache-main.c | 8 ++++---- > >>>>> drivers/staging/zram/zram_drv.c | 8 ++++---- > >>>>> drivers/staging/zram/zram_drv.h | 2 +- > >>>>> drivers/staging/zsmalloc/zsmalloc-main.c | 28 > >>>>> ++++++++++++++-------------- > >>>>> drivers/staging/zsmalloc/zsmalloc.h | 15 +++++++++++---- > >>>>> 5 files changed, 34 insertions(+), 27 deletions(-) > >>>> > >>>> This was a long pending change. Thanks! > >>> > >>> > >>> The reason I hadn't done it before is that it introduces a checkpatch > >>> warning: > >>> > >>> WARNING: do not add new typedefs > >>> #303: FILE: drivers/staging/zsmalloc/zsmalloc.h:19: > >>> +typedef void * zs_handle; > >>> > >> > >> > >> Yes. I did it but I think we are (a) of chapter 5: Typedefs in Documentation/CodingStyle. > >> > >> (a) totally opaque objects (where the typedef is actively used to _hide_ > >> what the object is). > >> > >> No? > > > > No. > > > > Don't add new typedefs to the kernel. Just use a structure if you need > > to. > > > I tried it but failed because there were already tightly coupling between [zcache|zram] > and zsmalloc. > They already knows handle's internal well so they used it as pointer, even zcache keeps > handle's value as some key in tmem_put and tmem_get > AFAIK, ramster also will use zsmalloc sooner or later and add more coupling codes. Sigh. > Please fix it as soon as possible. > > Dan, Seth > Any ideas? struct zs { void *ptr; }; And pass that structure around? -- 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/