From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Schwab Subject: Re: [patch] isdn: fix a wrapping bug in isdn_ppp_ioctl() Date: Wed, 10 Oct 2012 15:58:38 +0200 Message-ID: References: <20121010093816.GA3669@elgon.mountain> <1349864358.2386.27.camel@joe-AO722> <1349874007.2386.42.camel@joe-AO722> Mime-Version: 1.0 Content-Type: text/plain Cc: Dan Carpenter , Karsten Keil , "David S. Miller" , Masanari Iida , netdev@vger.kernel.org, kernel-janitors@vger.kernel.org To: Joe Perches Return-path: Received: from mail-out.m-online.net ([212.18.0.9]:58668 "EHLO mail-out.m-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755954Ab2JJN6l (ORCPT ); Wed, 10 Oct 2012 09:58:41 -0400 In-Reply-To: <1349874007.2386.42.camel@joe-AO722> (Joe Perches's message of "Wed, 10 Oct 2012 06:00:07 -0700") Sender: netdev-owner@vger.kernel.org List-ID: Sorry, I was misremembering the history of the bit ops. There has historically been issues with varying bit order, but noadays set_bit is always defined consistently with C shifts. But another issue, set_bit is an atomic operation which may be significantly more expensive than the equivalent C operation. Better use __set_bit when atomicity is not needed. Andreas. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."