Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760680Ab3GaSAh (ORCPT ); Wed, 31 Jul 2013 14:00:37 -0400 Received: from mail-oa0-f49.google.com ([209.85.219.49]:52607 "EHLO mail-oa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755202Ab3GaSAe (ORCPT ); Wed, 31 Jul 2013 14:00:34 -0400 MIME-Version: 1.0 In-Reply-To: <51F8DCFC.9050205@linux.vnet.ibm.com> References: <1374526866-6813-1-git-send-email-bp@alien8.de> <20130724171347.GB29756@naverao1-tp.watson.ibm.com> <1374686598.18818.18.camel@joe-AO722> <51F10AA8.2050901@linux.vnet.ibm.com> <51F8DCFC.9050205@linux.vnet.ibm.com> From: Bjorn Helgaas Date: Wed, 31 Jul 2013 12:00:13 -0600 Message-ID: Subject: Re: [PATCH] APEI/ERST: Fix error message formatting To: "Naveen N. Rao" Cc: Joe Perches , Borislav Petkov , LKML , Borislav Petkov , Anton Vorontsov , Colin Cross , Kees Cook , Tony Luck , Len Brown , "Rafael J. Wysocki" , "linux-acpi@vger.kernel.org" , "Huang, Ying" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1367 Lines: 29 On Wed, Jul 31, 2013 at 3:46 AM, Naveen N. Rao wrote: > My key question was about why we are using a field width of 10 implying a > 32-bit value, rather than a field width of 18 as suggested by the data type? > This shouldn't truncate the value, but if we are specifying the field width > for alignment, seems to me it is better to match the data type. %pR uses a field width of 10 (two for "0x", eight for the value) simply because the majority of resource values fit in 32 bits. Larger values extend the width, so it's not a question of truncating any data. But it's no fun to read memory addresses when most of them have eight extra leading zeros (the high 32-bits of a 64-bit value). I think the same applies here; most ACPI table addresses still fit in 32 bits. We *do* use a field width of 18 for the e820 table, even though many of those regions fit in 32 bits. But that's sort of an exception because it's a table where addresses above 4GB are pretty common. But at the end of the day, I guess I'm just stating my personal preferences and yours might be different. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/