From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH] xt_log.h: don't use xchg() for simple assignment Date: Fri, 23 Mar 2012 04:51:45 -0700 Message-ID: <1332503505.4858.2.camel@edumazet-laptop> References: <4F588DD8020000780007711C@nat28.tlf.novell.com> <20120323100705.GA22309@1984> <4F6C5B03020000780007A7ED@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Pablo Neira Ayuso , kaber@trash.net, netfilter-devel@vger.kernel.org To: Jan Beulich Return-path: Received: from mail-gy0-f174.google.com ([209.85.160.174]:59332 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758193Ab2CWLvt (ORCPT ); Fri, 23 Mar 2012 07:51:49 -0400 Received: by ghrr11 with SMTP id r11so2633105ghr.19 for ; Fri, 23 Mar 2012 04:51:48 -0700 (PDT) In-Reply-To: <4F6C5B03020000780007A7ED@nat28.tlf.novell.com> Sender: netfilter-devel-owner@vger.kernel.org List-ID: Le vendredi 23 mars 2012 =C3=A0 10:14 +0000, Jan Beulich a =C3=A9crit : > >>> On 23.03.12 at 11:07, Pablo Neira Ayuso wro= te: > > 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 com= piler > >> warning about an unused expression result. As only an assignment i= s > >> intended here, convert it to such. > >>=20 > >> Signed-off-by: Jan Beulich > >>=20 > >> --- > >> include/net/netfilter/xt_log.h | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >>=20 > >> --- 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 !=3D &emergency)) > >> kfree(m); > >> else { > >> - xchg(&emergency_ptr, m); > >> + emergency_ptr =3D m; > >=20 > > That xchg is there for some reason. I think it's better if you just > > cast it to void. >=20 > 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. >=20 Hmm I missed your patch Jan, and you're right, a plain write is OK here= =2E Acked-by: Eric Dumazet -- To unsubscribe from this list: send the line "unsubscribe netfilter-dev= el" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html