From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264511AbUD0Xxi (ORCPT ); Tue, 27 Apr 2004 19:53:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264412AbUD0Xxi (ORCPT ); Tue, 27 Apr 2004 19:53:38 -0400 Received: from ausmtp02.au.ibm.com ([202.81.18.187]:40187 "EHLO ausmtp02.au.ibm.com") by vger.kernel.org with ESMTP id S264511AbUD0XxZ (ORCPT ); Tue, 27 Apr 2004 19:53:25 -0400 Subject: [PATCH] Fix cpu iterator on empty bitmask From: Rusty Russell To: Joel Schopp , Anton Blanchard , Andrew Morton Cc: lkml - Kernel Mailing List Content-Type: text/plain Message-Id: <1083109972.2150.124.camel@bach> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Wed, 28 Apr 2004 09:52:53 +1000 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Name: Fix cpumask iterator over empty cpu set Status: Trivial Can't use _ffs() without first checking for zero, and if bits beyond NR_CPUS set it'll give bogus results. Use find_first_bit diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .26180-linux-2.6.6-rc2-bk5/include/asm-generic/cpumask_arith.h .26180-linux-2.6.6-rc2-bk5.updated/include/asm-generic/cpumask_arith.h --- .26180-linux-2.6.6-rc2-bk5/include/asm-generic/cpumask_arith.h 2004-01-10 13:59:33.000000000 +1100 +++ .26180-linux-2.6.6-rc2-bk5.updated/include/asm-generic/cpumask_arith.h 2004-04-28 09:50:23.000000000 +1000 @@ -43,7 +43,7 @@ #define cpus_promote(map) ({ map; }) #define cpumask_of_cpu(cpu) ({ ((cpumask_t)1) << (cpu); }) -#define first_cpu(map) __ffs(map) +#define first_cpu(map) find_first_bit(&(map), NR_CPUS) #define next_cpu(cpu, map) find_next_bit(&(map), NR_CPUS, cpu + 1) #endif /* __ASM_GENERIC_CPUMASK_ARITH_H */ -- Anyone who quotes me in their signature is an idiot -- Rusty Russell