From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946013AbWGOKcU (ORCPT ); Sat, 15 Jul 2006 06:32:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1946015AbWGOKcU (ORCPT ); Sat, 15 Jul 2006 06:32:20 -0400 Received: from rhun.apana.org.au ([64.62.148.172]:53519 "EHLO arnor.apana.org.au") by vger.kernel.org with ESMTP id S1946013AbWGOKcT (ORCPT ); Sat, 15 Jul 2006 06:32:19 -0400 Date: Sat, 15 Jul 2006 20:32:07 +1000 To: David Miller Cc: akpm@osdl.org, linux-kernel@vger.kernel.org Subject: Re: 2.6.18-rc1-mm2 Message-ID: <20060715103207.GA17727@gondor.apana.org.au> References: <20060715002623.GE9334@gondor.apana.org.au> <20060714173517.cdd58097.akpm@osdl.org> <20060715010645.GB11515@gondor.apana.org.au> <20060714.224001.71089810.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060714.224001.71089810.davem@davemloft.net> User-Agent: Mutt/1.5.9i From: Herbert Xu Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 14, 2006 at 10:40:01PM -0700, David Miller wrote: > > Wouldn't it be cleaner to wrap this unlikely around > the top-level "({ })"? When it sits on a line by > itself it looks strange, that much is true :) Sure, in fact there was a name clash as well with __ret and I forgot to update the arch-specific versions. [PATCH] Let WARN_ON/WARN_ON_ONCE return the condition Letting WARN_ON/WARN_ON_ONCE return the condition means that you could do if (WARN_ON(blah)) { handle_impossible_case } Rather than if (unlikely(blah)) { WARN_ON(1) handle_impossible_case } I checked all the newly added WARN_ON_ONCE users and none of them test the return status so we can still change it. Signed-off-by: Herbert Xu herbert@gondor.apana.org.au> Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h index 8ceab7b..672ca90 100644 --- a/include/asm-generic/bug.h +++ b/include/asm-generic/bug.h @@ -16,12 +16,14 @@ #define BUG_ON(condition) do { if (unlik #endif #ifndef HAVE_ARCH_WARN_ON -#define WARN_ON(condition) do { \ - if (unlikely((condition)!=0)) { \ +#define WARN_ON(condition) unlikely({ \ + int __ret_warn_on = (condition); \ + if (unlikely(__ret_warn_on)) { \ printk("BUG: warning at %s:%d/%s()\n", __FILE__, __LINE__, __FUNCTION__); \ dump_stack(); \ } \ -} while (0) + __ret_warn_on; \ +}) #endif #else /* !CONFIG_BUG */ @@ -34,21 +36,19 @@ #define BUG_ON(condition) do { if (condi #endif #ifndef HAVE_ARCH_WARN_ON -#define WARN_ON(condition) do { if (condition) ; } while(0) +#define WARN_ON(condition) unlikely((condition)) #endif #endif #define WARN_ON_ONCE(condition) \ -({ \ +unlikely({ \ static int __warn_once = 1; \ - int __ret = 0; \ + int __ret_warn_once = (condition); \ \ - if (unlikely((condition) && __warn_once)) { \ - __warn_once = 0; \ - WARN_ON(1); \ - __ret = 1; \ - } \ - __ret; \ + if (likely(__warn_once)) \ + if (WARN_ON(__ret_warn_once)) \ + __warn_once = 0; \ + __ret_warn_once; \ }) #ifdef CONFIG_SMP diff --git a/include/asm-powerpc/bug.h b/include/asm-powerpc/bug.h index f44b529..a5f503f 100644 --- a/include/asm-powerpc/bug.h +++ b/include/asm-powerpc/bug.h @@ -70,9 +70,10 @@ #define __WARN() do { \ "i" (__FILE__), "i" (__FUNCTION__)); \ } while (0) -#define WARN_ON(x) do { \ - if (__builtin_constant_p(x)) { \ - if (x) \ +#define WARN_ON(x) unlikely({ \ + long __ret_warn_on = (x); \ + if (__builtin_constant_p(__ret_warn_on)) { \ + if (__ret_warn_on) \ __WARN(); \ } else { \ __asm__ __volatile__( \ @@ -80,11 +81,12 @@ #define WARN_ON(x) do { \ ".section __bug_table,\"a\"\n" \ "\t"PPC_LONG" 1b,%1,%2,%3\n" \ ".previous" \ - : : "r" ((long)(x)), \ + : : "r" (__ret_warn_on), \ "i" (__LINE__ + BUG_WARNING_TRAP), \ "i" (__FILE__), "i" (__FUNCTION__)); \ } \ -} while (0) + __ret_warn_on; \ +}) #define HAVE_ARCH_BUG #define HAVE_ARCH_BUG_ON