x86, nmi_watchdog: Remove ARCH_HAS_NMI_WATCHDOG and rely on CONFIG_HARDLOCKUP_DETECTOR

The x86 arch has shifted its use of the nmi_watchdog from a
local implementation to the global one provide by
kernel/watchdog.c.  This shift has caused a whole bunch of
compile problems under different config options.  I attempt to
simplify things with the patch below.

In order to simplify things, I had to come to terms with the
meaning of two terms ARCH_HAS_NMI_WATCHDOG and
CONFIG_HARDLOCKUP_DETECTOR.  Basically they mean the same thing,
the former on a local level and the latter on a global level.

With the old x86 nmi watchdog gone, there is no need to rely on
defining the ARCH_HAS_NMI_WATCHDOG variable because it doesn't
make sense any more.  x86 will now use the global
implementation.

The changes below do a few things.  First it changes the few
places that relied on ARCH_HAS_NMI_WATCHDOG to use
CONFIG_X86_LOCAL_APIC (the former was an alias for the latter
anyway, so nothing unusual here).  Those pieces of code were
relying more on local apic functionality the nmi watchdog
functionality, so the change should make sense.

Second, I removed the x86 implementation of
touch_nmi_watchdog().  It isn't need now, instead x86 will rely
on kernel/watchdog.c's implementation.

Third, I removed the #define ARCH_HAS_NMI_WATCHDOG itself from
x86.  And tweaked the include/linux/nmi.h file to tell users to
look for an externally defined touch_nmi_watchdog in the case of
ARCH_HAS_NMI_WATCHDOG _or_ CONFIG_HARDLOCKUP_DETECTOR. This
changes removes some of the ugliness in that file.

Finally, I added a Kconfig dependency for
CONFIG_HARDLOCKUP_DETECTOR that said you can't have
ARCH_HAS_NMI_WATCHDOG _and_ CONFIG_HARDLOCKUP_DETECTOR.  You can
only have one nmi_watchdog.

Tested with
ARCH=i386: allnoconfig, defconfig, allyesconfig, (various broken
configs) ARCH=x86_64: allnoconfig, defconfig, allyesconfig,
(various broken configs)

Hopefully, after this patch I won't get any more compile broken
emails. :-)

v3:
  changed a couple of 'linux/nmi.h' -> 'asm/nmi.h' to pick-up correct function
  prototypes when CONFIG_HARDLOCKUP_DETECTOR is not set.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: fweisbec@gmail.com
LKML-Reference: <1293044403-14117-1-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
index 13b0ebaa512f77764e06956632b32755f8ca2bfa..ba870bb6dd8ef30ab81a317a8eb43dcb83066630 100644 (file)
--- a/arch/x86/include/asm/irq.h
+++ b/arch/x86/include/asm/irq.h
@@ -15,10 +15,6 @@ static inline int irq_canonicalize(int irq)
        return ((irq == 2) ? 9 : irq);
 }
 
-#ifdef CONFIG_X86_LOCAL_APIC
-# define ARCH_HAS_NMI_WATCHDOG
-#endif
-
 #ifdef CONFIG_X86_32
 extern void irq_ctx_init(int cpu);
 #else

diff --git a/arch/x86/include/asm/nmi.h b/arch/x86/include/asm/nmi.h
index 3545838cddebc7f45e233ebc77fe6954fb886f9b..c4021b9535102547712c92203e8afe5809e567fc 100644 (file)
--- a/arch/x86/include/asm/nmi.h
+++ b/arch/x86/include/asm/nmi.h
@@ -5,7 +5,7 @@
 #include <asm/irq.h>
 #include <asm/io.h>
 
-#ifdef ARCH_HAS_NMI_WATCHDOG
+#ifdef CONFIG_X86_LOCAL_APIC
 
 extern void die_nmi(char *str, struct pt_regs *regs, int do_panic);
 extern int avail_to_resrv_perfctr_nmi_bit(unsigned int);

diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c
index 93da91df5b381b87db9482bb58c3bcc4f476a557..c57d0b5994489df472d38566fb6a65da45894c7c 100644 (file)
--- a/arch/x86/kernel/apic/hw_nmi.c
+++ b/arch/x86/kernel/apic/hw_nmi.c
@@ -17,7 +17,6 @@
 #include <linux/nmi.h>
 #include <linux/module.h>
 
-#ifdef ARCH_HAS_NMI_WATCHDOG
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
 u64 hw_nmi_get_sample_period(void)
 {
@@ -25,15 +24,6 @@ u64 hw_nmi_get_sample_period(void)
 }
 #endif
 
-#ifndef CONFIG_HARDLOCKUP_DETECTOR
-void touch_nmi_watchdog(void)
-{
-       touch_softlockup_watchdog();
-}
-EXPORT_SYMBOL(touch_nmi_watchdog);
-#endif
-#endif
-
 #ifdef arch_trigger_all_cpu_backtrace
 /* For reliability, we're prepared to waste bits here. */
 static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly;

diff --git a/arch/x86/kernel/cpu/perfctr-watchdog.c b/arch/x86/kernel/cpu/perfctr-watchdog.c
index 14d45928c2829cef9f690834e20caa23ede13e03..d5a236615501fd6a41fb6f6bc76bfd2369a47bc5 100644 (file)
--- a/arch/x86/kernel/cpu/perfctr-watchdog.c
+++ b/arch/x86/kernel/cpu/perfctr-watchdog.c
@@ -16,7 +16,7 @@
 #include <linux/kernel.h>
 #include <linux/bitops.h>
 #include <linux/smp.h>
-#include <linux/nmi.h>
+#include <asm/nmi.h>
 #include <linux/kprobes.h>
 
 #include <asm/apic.h>

diff --git a/arch/x86/oprofile/op_model_p4.c b/arch/x86/oprofile/op_model_p4.c
index 182558dd5515add420a27dfa58304d04b6a6f71a..9fadec074142b11afcb39e73627dc4c4fd8e14dd 100644 (file)
--- a/arch/x86/oprofile/op_model_p4.c
+++ b/arch/x86/oprofile/op_model_p4.c
@@ -11,7 +11,7 @@
 #include <linux/oprofile.h>
 #include <linux/smp.h>
 #include <linux/ptrace.h>
-#include <linux/nmi.h>
+#include <asm/nmi.h>
 #include <asm/msr.h>
 #include <asm/fixmap.h>
 #include <asm/apic.h>

diff --git a/drivers/watchdog/hpwdt.c b/drivers/watchdog/hpwdt.c
index c19f4a20794adb38222511c76c721bced3b218a3..dea7b5bf6e2ccd986cf99840db504d6a38382293 100644 (file)
--- a/drivers/watchdog/hpwdt.c
+++ b/drivers/watchdog/hpwdt.c
@@ -642,7 +642,7 @@ static struct notifier_block die_notifier = {
  */
 
 #ifdef CONFIG_HPWDT_NMI_DECODING
-#ifdef ARCH_HAS_NMI_WATCHDOG
+#ifdef CONFIG_X86_LOCAL_APIC
 static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
 {
        /*
@@ -657,7 +657,7 @@ static void __devinit hpwdt_check_nmi_decoding(struct pci_dev *dev)
        dev_warn(&dev->dev, "NMI decoding is disabled. "
                "Your kernel does not support a NMI Watchdog.\n");
 }
-#endif /* ARCH_HAS_NMI_WATCHDOG */
+#endif /* CONFIG_X86_LOCAL_APIC */
 
 static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
 {

diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index 17ccf44e7dcb6b52298d0d615d3c48ee25caedf1..c536f8545f74c11e345943187f201bfc25e48baa 100644 (file)
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -14,18 +14,14 @@
  * may be used to reset the timeout - for code which intentionally
  * disables interrupts for a long time. This call is stateless.
  */
-#ifdef ARCH_HAS_NMI_WATCHDOG
+#if defined(ARCH_HAS_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
 #include <asm/nmi.h>
 extern void touch_nmi_watchdog(void);
 #else
-#ifndef CONFIG_HARDLOCKUP_DETECTOR
 static inline void touch_nmi_watchdog(void)
 {
        touch_softlockup_watchdog();
 }
-#else
-extern void touch_nmi_watchdog(void);
-#endif
 #endif
 
 /*

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 28b42b9274d0b5fe47522d9df8158498be12319a..2d05adb984018776610f573de126f14bda4c9d2e 100644 (file)
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -173,7 +173,8 @@ config LOCKUP_DETECTOR
          An NMI is generated every 60 seconds or so to check for hardlockups.
 
 config HARDLOCKUP_DETECTOR
-       def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI
+       def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI && \
+                !ARCH_HAS_NMI_WATCHDOG
 
 config BOOTPARAM_SOFTLOCKUP_PANIC
        bool "Panic (Reboot) On Soft Lockups"