From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752831Ab1GOPyw (ORCPT ); Fri, 15 Jul 2011 11:54:52 -0400 Received: from mail.perches.com ([173.55.12.10]:4018 "EHLO mail.perches.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751910Ab1GOPyv (ORCPT ); Fri, 15 Jul 2011 11:54:51 -0400 Subject: Re: [PATCH 03/11] dynamic_debug: Remove uses of KERN_CONT in dynamic_emit_prefix From: Joe Perches To: Jason Baron Cc: Bart Van Assche , gregkh@suse.de, jim.cromie@gmail.com, linux-kernel@vger.kernel.org In-Reply-To: <20110715150734.GA2493@redhat.com> References: <07ef9de13b16d5c50bc36f8c8d9a9aa28a05f2ca.1310657068.git.jbaron@redhat.com> <20110715150734.GA2493@redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Fri, 15 Jul 2011 08:54:50 -0700 Message-ID: <1310745290.7582.40.camel@Joe-Laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2011-07-15 at 11:07 -0400, Jason Baron wrote: > On Fri, Jul 15, 2011 at 12:04:22PM +0200, Bart Van Assche wrote: > > On Thu, Jul 14, 2011 at 6:09 PM, Jason Baron wrote: > > > + char tid[sizeof(int) + sizeof(int)/2 + 4]; > > > + char lineno[sizeof(int) + sizeof(int)/2]; > > It's not clear to me where the array bounds come from ? Also, why > > sizeof(int) + sizeof(int)/2 instead of sizeof(int)*3 + 1 ? > hmmm...for the tid it bounded by PID_MAX_LIMIT, which is 4 million, so > you need 7 characters + 3 for the brackets and space = 10. So that looks > right to me. Although I'm not sure where the sizeof() comes from? Joe? It's incorrect. sizeof(int) => # decimal digits + terminating 0 4 => 11 8 => 21 I think I meant to type sizeof(int) * 2 + sizeof(int) / 2 + 1 > For the lineno, it is 24 bits, so it can be 2^24 = 16,777,216, or 8 > characters, so I think the 6 is incorrect. Although, in practice I don't > think we have any files that are that big. Then the tid size should be based on PID_MAX_LIMIT. I don't much care. I just wanted to minimize stack consumption.