[tip:x86/reboot] x86/reboot: Update nonmi_ipi parameter

From: tip-bot for Don Zickus
Date: Mon May 14 2012 - 09:06:40 EST


Commit-ID: 3aac27aba79b7c52e709ef6de0f7d8139caedc01
Gitweb: http://git.kernel.org/tip/3aac27aba79b7c52e709ef6de0f7d8139caedc01
Author: Don Zickus <dzickus@xxxxxxxxxx>
AuthorDate: Fri, 11 May 2012 14:41:15 -0400
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Mon, 14 May 2012 11:49:38 +0200

x86/reboot: Update nonmi_ipi parameter

Update the nonmi_ipi parameter to reflect the simple change
instead of the previous complicated one. There should be less
of a need to use it but there may still be corner cases on older
hardware that stumble into NMI issues.

Signed-off-by: Don Zickus <dzickus@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1336761675-24296-4-git-send-email-dzickus@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/kernel/smp.c | 12 ++++--------
1 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 228e740..48d2b7d 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -110,6 +110,7 @@
*/

static atomic_t stopping_cpu = ATOMIC_INIT(-1);
+static bool smp_no_nmi_ipi = false;

/*
* this function sends a 'reschedule' IPI to another CPU.
@@ -216,7 +217,7 @@ static void native_stop_other_cpus(int wait)
}

/* if the REBOOT_VECTOR didn't work, try with the NMI */
- if ((num_online_cpus() > 1)) {
+ if ((num_online_cpus() > 1) && (!smp_no_nmi_ipi)) {
if (register_nmi_handler(NMI_LOCAL, smp_stop_nmi_callback,
NMI_FLAG_FIRST, "smp_stop"))
/* Note: we ignore failures here */
@@ -245,11 +246,6 @@ finish:
local_irq_restore(flags);
}

-static void native_smp_disable_nmi_ipi(void)
-{
- smp_ops.stop_other_cpus = native_irq_stop_other_cpus;
-}
-
/*
* Reschedule call back.
*/
@@ -283,8 +279,8 @@ void smp_call_function_single_interrupt(struct pt_regs *regs)

static int __init nonmi_ipi_setup(char *str)
{
- native_smp_disable_nmi_ipi();
- return 1;
+ smp_no_nmi_ipi = true;
+ return 1;
}

__setup("nonmi_ipi", nonmi_ipi_setup);
--
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