From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx117.postini.com [74.125.245.117]) by kanga.kvack.org (Postfix) with SMTP id 411616B0044 for ; Wed, 25 Apr 2012 09:35:31 -0400 (EDT) Received: by qcsd16 with SMTP id d16so70988qcs.14 for ; Wed, 25 Apr 2012 06:35:30 -0700 (PDT) Message-ID: <4F97FD9D.9090105@vflare.org> Date: Wed, 25 Apr 2012 09:35:25 -0400 From: Nitin Gupta MIME-Version: 1.0 Subject: Re: [PATCH 5/6] zsmalloc: remove unnecessary type casting References: <1335334994-22138-1-git-send-email-minchan@kernel.org> <1335334994-22138-6-git-send-email-minchan@kernel.org> In-Reply-To: <1335334994-22138-6-git-send-email-minchan@kernel.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Greg Kroah-Hartman , Seth Jennings , Dan Magenheimer , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org On 04/25/2012 02:23 AM, Minchan Kim wrote: > Let's remove unnecessary type casting of (void *). > > Signed-off-by: Minchan Kim > --- > drivers/staging/zsmalloc/zsmalloc-main.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/staging/zsmalloc/zsmalloc-main.c b/drivers/staging/zsmalloc/zsmalloc-main.c > index b7d31cc..ff089f8 100644 > --- a/drivers/staging/zsmalloc/zsmalloc-main.c > +++ b/drivers/staging/zsmalloc/zsmalloc-main.c > @@ -644,8 +644,7 @@ void zs_free(struct zs_pool *pool, void *obj) > spin_lock(&class->lock); > > /* Insert this object in containing zspage's freelist */ > - link = (struct link_free *)((unsigned char *)kmap_atomic(f_page) > - + f_offset); > + link = (struct link_free *)(kmap_atomic(f_page) + f_offset); > link->next = first_page->freelist; > kunmap_atomic(link); > first_page->freelist = obj; Incrementing a void pointer looks weired and should not be allowed by C compilers though gcc and clang seem to allow this without any warnings. (fortunately C++ forbids incrementing void pointers) So, we should keep this cast to unsigned char pointer to avoid relying on a non-standard, compiler specific behavior. Thanks, Nitin -- 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