From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 19 Feb 2003 13:01:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 19 Feb 2003 13:01:15 -0500 Received: from host194.steeleye.com ([66.206.164.34]:2567 "EHLO pogo.mtv1.steeleye.com") by vger.kernel.org with ESMTP id ; Wed, 19 Feb 2003 13:01:14 -0500 Subject: Re: [PATCH] add new DMA_ADDR_T_SIZE define From: James Bottomley To: Ion Badulescu Cc: linux-kernel@vger.kernel.org Content-Type: text/plain Content-Transfer-Encoding: 7bit X-Mailer: Ximian Evolution 1.0.8 (1.0.8-9) Date: 19 Feb 2003 13:11:07 -0500 Message-Id: <1045678275.2033.37.camel@mulgrave> Mime-Version: 1.0 X-AntiVirus: scanned for viruses by AMaViS 0.2.1 (http://amavis.org/) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > 3. use run-time checks all over the place, of the > "sizeof(dma_addr_t)==sizeof(u64)" kind, which adds unnecessary > overhead to > all platforms. Actually, these aren't technically run time checks. Although the cpp can't be used for sizeof(), the compiler (at least gcc) does seem to have enough sense to optimise away if(..) branches it has enough information to know won't be taken at compile time. As long as this optimisation works, I think the if(sizeof(..)) checks are fine for this. James