From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755111AbYFHU2b (ORCPT ); Sun, 8 Jun 2008 16:28:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754375AbYFHU2V (ORCPT ); Sun, 8 Jun 2008 16:28:21 -0400 Received: from wa-out-1112.google.com ([209.85.146.178]:38292 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753902AbYFHU2T convert rfc822-to-8bit (ORCPT ); Sun, 8 Jun 2008 16:28:19 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=XShrWp5zsgNNsg3AQFlOt69yEOJde9nqg4Qzg6LHD2BN42qvMyHiTv8qydvMyTKoXH mwlCmRZvSVXOw0L4AQo3tNJRR04cJIFU33Igb957tEaJWLSF0oa8oq6e/iuzNoQB1G7x vw2JaoImljZMJhRM0KxjxOEgPai+Uuux+MbHg= Message-ID: Date: Mon, 9 Jun 2008 00:28:19 +0400 From: "Cyrill Gorcunov" To: "=?ISO-8859-1?Q?N=E9meth_M=E1rton?=" , "Thomas Gleixner" , "Ingo Molnar" , LKML Subject: Re: [PATCH] x86: cleanups to nmi_watchdog variable In-Reply-To: <484C078A.7090700@freemail.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Content-Disposition: inline References: <484AAD0B.1030407@freemail.hu> <20080608155649.GC7020@cvg> <484C078A.7090700@freemail.hu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Btw, if you interested to clean it up (which means not cleanup in real :) i suggest to analize _if_ there is benefit from sign changing. Mark that -1 is the 0xff... form of presentation for unsigned type. And thanks for catching this. It defenitely should be simplified once. On 6/8/08, Németh Márton wrote: > Cyrill Gorcunov wrote: >> | From: Márton Németh >> | >> | Use NMI_NONE instead of 0. As the symbol NMI_DISABLED equals to -1, >> | the nmi_watchdog variable should also be signed. >> | >> | Signed-off-by: Márton Németh >> | --- >> | diff -upr linux-2.6.26-rc5.orig/arch/x86/kernel/io_apic_32.c >> linux-2.6.26-rc5/arch/x86/kernel/io_apic_32.c >> | --- linux-2.6.26-rc5.orig/arch/x86/kernel/io_apic_32.c 2008-06-07 >> 12:35:24.000000000 +0200 >> | +++ linux-2.6.26-rc5/arch/x86/kernel/io_apic_32.c 2008-06-07 >> 12:40:20.000000000 +0200 >> | @@ -2217,7 +2217,7 @@ static inline void __init check_timer(vo >> | >> | if (nmi_watchdog == NMI_IO_APIC) { >> | printk(KERN_WARNING "timer doesn't work through the IO-APIC - >> disabling NMI Watchdog!\n"); >> | - nmi_watchdog = 0; >> | + nmi_watchdog = NMI_NONE; >> | } >> | >> | printk(KERN_INFO "...trying to set up timer as Virtual Wire IRQ..."); >> | diff -upr linux-2.6.26-rc5.orig/arch/x86/kernel/io_apic_64.c >> linux-2.6.26-rc5/arch/x86/kernel/io_apic_64.c >> | --- linux-2.6.26-rc5.orig/arch/x86/kernel/io_apic_64.c 2008-06-05 >> 18:39:49.000000000 +0200 >> | +++ linux-2.6.26-rc5/arch/x86/kernel/io_apic_64.c 2008-06-07 >> 12:37:01.000000000 +0200 >> | @@ -1735,7 +1735,7 @@ static inline void __init check_timer(vo >> | >> | if (nmi_watchdog == NMI_IO_APIC) { >> | printk(KERN_WARNING "timer doesn't work through the IO-APIC - >> disabling NMI Watchdog!\n"); >> | - nmi_watchdog = 0; >> | + nmi_watchdog = NMI_NONE; >> | } >> | >> | apic_printk(APIC_VERBOSE, KERN_INFO "...trying to set up timer as >> Virtual Wire IRQ..."); >> | diff -upr linux-2.6.26-rc5.orig/arch/x86/kernel/nmi_32.c >> linux-2.6.26-rc5/arch/x86/kernel/nmi_32.c >> | --- linux-2.6.26-rc5.orig/arch/x86/kernel/nmi_32.c 2008-06-05 >> 18:39:49.000000000 +0200 >> | +++ linux-2.6.26-rc5/arch/x86/kernel/nmi_32.c 2008-06-07 >> 11:19:55.000000000 +0200 >> | @@ -43,7 +43,7 @@ static cpumask_t backtrace_mask = CPU_MA >> | */ >> | atomic_t nmi_active = ATOMIC_INIT(0); /* oprofile uses this */ >> | >> | -unsigned int nmi_watchdog = NMI_DEFAULT; >> | +int nmi_watchdog = NMI_DEFAULT; >> | static unsigned int nmi_hz = HZ; >> | >> | static DEFINE_PER_CPU(short, wd_enabled); >> | diff -upr linux-2.6.26-rc5.orig/arch/x86/kernel/nmi_64.c >> linux-2.6.26-rc5/arch/x86/kernel/nmi_64.c >> | --- linux-2.6.26-rc5.orig/arch/x86/kernel/nmi_64.c 2008-06-05 >> 18:39:49.000000000 +0200 >> | +++ linux-2.6.26-rc5/arch/x86/kernel/nmi_64.c 2008-06-07 >> 11:20:00.000000000 +0200 >> | @@ -43,7 +43,7 @@ static cpumask_t backtrace_mask = CPU_MA >> | atomic_t nmi_active = ATOMIC_INIT(0); /* oprofile uses this */ >> | static int panic_on_timeout; >> | >> | -unsigned int nmi_watchdog = NMI_DEFAULT; >> | +int nmi_watchdog = NMI_DEFAULT; >> | static unsigned int nmi_hz = HZ; >> | >> | static DEFINE_PER_CPU(short, wd_enabled); >> | diff -upr linux-2.6.26-rc5.orig/include/asm-x86/nmi.h >> linux-2.6.26-rc5/include/asm-x86/nmi.h >> | --- linux-2.6.26-rc5.orig/include/asm-x86/nmi.h 2008-06-05 >> 18:40:12.000000000 +0200 >> | +++ linux-2.6.26-rc5/include/asm-x86/nmi.h 2008-06-07 11:21:20.000000000 >> +0200 >> | @@ -61,7 +61,7 @@ extern void enable_timer_nmi_watchdog(vo >> | extern int nmi_watchdog_tick(struct pt_regs *regs, unsigned reason); >> | >> | extern atomic_t nmi_active; >> | -extern unsigned int nmi_watchdog; >> | +extern int nmi_watchdog; >> | #define NMI_DISABLED -1 >> | #define NMI_NONE 0 >> | #define NMI_IO_APIC 1 >> | >> >> We should leave nmi_watchdog as unsigned. The only snippet which >> could be reviewed as controversy point - is touch_nmi_watchdog() >> where we just test nmi_watchdog for being greater than 0. Actually >> there NMI_NONE should be used instead. But frankly some additional >> simplification is needed. > > Don't forget that the NMI_DEFAULT symbol in include/asm-x86/nmi.h also > equals to > NMI_DISABLED, which is -1. > > Márton Németh > >