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x86: cleanups to nmi_watchdog variable

PATCH In review Németh Márton 2 participants 6 messages Jun 7, 2008 – Jun 8, 2008 x86

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Németh Márton

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#0 lore raw

PATCH 1/1 x86: cleanups to nmi_watchdog variable

From: Márton Németh <[email protected]>

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 <[email protected]>

---

arch/x86/kernel/io_apic_32.c +1 -1
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
@@ -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...");
arch/x86/kernel/io_apic_64.c +1 -1
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
@@ -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...");
arch/x86/kernel/nmi_32.c +1 -1
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
@@ -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);
arch/x86/kernel/nmi_64.c +1 -1
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
@@ -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);
include/asm-x86/nmi.h +1 -1
diff -upr linux-2.6.26-rc5.orig/include/asm-x86/nmi.h linux-2.6.26-rc5/include/asm-x86/nmi.h
@@ -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
#1 lore raw

[=?ISO-8859-2?Q?N=E9meth_M=E1rton_ - Sat, Jun 07, 2008 at 05:45:15PM +0200]

| From: Márton Németh <[email protected]>
| 
| 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 <[email protected]>
| ---
| 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
|

Good catch! Actually 0 -> NMI_NONE change already in -tip tree. Sign/signess mark - is good to be investigated. Thanks!

- Cyrill -

#2 lore raw
In reply to Németh Márton
| From: Márton Németh <[email protected]>
| 
| 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 <[email protected]>
| ---
| 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.

- Cyrill -

author
#3 lore raw
Quoted 69 lines · Cyrill Gorcunov
| From: Márton Németh <[email protected]>
| 
| 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 <[email protected]>
| ---
| 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
|
Quoted 5 lines

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

#4 lore raw

[=?ISO-8859-1?Q?N=E9meth_M=E1rton_ - Sun, Jun 08, 2008 at 06:23:38PM +0200]

| Cyrill Gorcunov wrote:
| > | From: Márton Németh <[email protected]>
| > | 
| > | 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 <[email protected]>
| > | ---
| > | 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
|

yes, i know

- Cyrill -

#5 lore raw
In reply to Németh Márton

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.

Quoted 101 lines · Németh Márton
Quoted 87 lines · Cyrill Gorcunov
| From: Márton Németh <[email protected]>
|
| 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 <[email protected]>
| ---
| 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
|
Quoted 5 lines

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