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| author | Ingo Molnar <mingo@elte.hu> | 2007-03-05 13:20:11 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-03-05 08:23:51 -0800 |
| commit | 6ebf622b2577c50b1f496bd6a5e8739e55ae7b1c (patch) | |
| tree | ae4da73844c08c9cfc6e934eabc55c1fb1188845 | |
| parent | 0d05ad2c09af9fb33ae76f9f8d1c4e4d1a9de92c (diff) | |
| download | linux-6ebf622b2577c50b1f496bd6a5e8739e55ae7b1c.tar.bz2 | |
[PATCH] disable NMI watchdog by default
there's a new NMI watchdog related problem: KVM crashes on certain
bzImages because ... we enable the NMI watchdog by default (even if the
user does not ask for it) , and no other OS on this planet does that so
KVM doesnt have emulation for that yet. So KVM injects a #GP, which
crashes the Linux guest:
general protection fault: 0000 [#1]
PREEMPT SMP
Modules linked in:
CPU: 0
EIP: 0060:[<c011a8ae>] Not tainted VLI
EFLAGS: 00000246 (2.6.20-rc5-rt0 #3)
EIP is at setup_apic_nmi_watchdog+0x26d/0x3d3
and no, i did /not/ request an nmi_watchdog on the boot command line!
Solution: turn off that darn thing! It's a debug tool, not a 'make life
harder' tool!!
with this patch the KVM guest boots up just fine.
And with this my laptop (Lenovo T60) also stopped its sporadic hard
hanging (sometimes in acpi_init(), sometimes later during bootup,
sometimes much later during actual use) as well. It hung with both
nmi_watchdog=1 and nmi_watchdog=2, so it's generally the fact of NMI
injection that is causing problems, not the NMI watchdog variant, nor
any particular bootup code.
[ NMI breaks on some systems, esp in combination with SMM -Arjan ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/asm-i386/nmi.h | 2 | ||||
| -rw-r--r-- | include/asm-x86_64/nmi.h | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/include/asm-i386/nmi.h b/include/asm-i386/nmi.h index b04333ea6f31..64544cb85d6a 100644 --- a/include/asm-i386/nmi.h +++ b/include/asm-i386/nmi.h @@ -33,7 +33,7 @@ extern int nmi_watchdog_tick (struct pt_regs * regs, unsigned reason); extern atomic_t nmi_active; extern unsigned int nmi_watchdog; -#define NMI_DEFAULT -1 +#define NMI_DEFAULT 0 #define NMI_NONE 0 #define NMI_IO_APIC 1 #define NMI_LOCAL_APIC 2 diff --git a/include/asm-x86_64/nmi.h b/include/asm-x86_64/nmi.h index 72375e7d32a8..ceb3d8dac33d 100644 --- a/include/asm-x86_64/nmi.h +++ b/include/asm-x86_64/nmi.h @@ -64,7 +64,7 @@ extern int setup_nmi_watchdog(char *); extern atomic_t nmi_active; extern unsigned int nmi_watchdog; -#define NMI_DEFAULT -1 +#define NMI_DEFAULT 0 #define NMI_NONE 0 #define NMI_IO_APIC 1 #define NMI_LOCAL_APIC 2 |