From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: Re: [PATCH] xt_log.h: don't use xchg() for simple assignment Date: Fri, 23 Mar 2012 10:14:11 +0000 Message-ID: <4F6C5B03020000780007A7ED@nat28.tlf.novell.com> References: <4F588DD8020000780007711C@nat28.tlf.novell.com> <20120323100705.GA22309@1984> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Cc: , To: "Pablo Neira Ayuso" Return-path: Received: from nat28.tlf.novell.com ([130.57.49.28]:15379 "EHLO nat28.tlf.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753493Ab2CWKNQ convert rfc822-to-8bit (ORCPT ); Fri, 23 Mar 2012 06:13:16 -0400 In-Reply-To: <20120323100705.GA22309@1984> Content-Disposition: inline Sender: netfilter-devel-owner@vger.kernel.org List-ID: >>> On 23.03.12 at 11:07, Pablo Neira Ayuso wrote: > On Thu, Mar 08, 2012 at 09:45:44AM +0000, Jan Beulich wrote: >> At least on ia64 the (bogus) use of xchg() here results in the compiler >> warning about an unused expression result. As only an assignment is >> intended here, convert it to such. >> >> Signed-off-by: Jan Beulich >> >> --- >> include/net/netfilter/xt_log.h | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> --- 3.3-rc6/include/net/netfilter/xt_log.h >> +++ 3.3-rc6-netfilter-xt_log-no-xchg/include/net/netfilter/xt_log.h >> @@ -47,7 +47,7 @@ static void sb_close(struct sbuff *m) >> if (likely(m != &emergency)) >> kfree(m); >> else { >> - xchg(&emergency_ptr, m); >> + emergency_ptr = m; > > That xchg is there for some reason. I think it's better if you just > cast it to void. If I knew the reason, I wouldn't mind doing so. But with no code comment and nothing said in the corresponding commit message I'm of the opinion that it is there just as a copy-and-paste result. Jan