linux-kernel - [PATCH] i386/x86_64: NMI watchdog: Remove spurious local_irq_enable() in check_nmi

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Message-ID: <a781481a0706070404r67a02caoc1b8b0f3a8f0f00b@mail.gmail.com>
Date:	Thu, 7 Jun 2007 16:34:52 +0530
From:	"Satyam Sharma" <satyam.sharma@...il.com>
To:	"Linux Kernel Mailing List" <linux-kernel@...r.kernel.org>
Cc:	"Ingo Molnar" <mingo@...hat.com>, "Andi Kleen" <ak@...e.de>
Subject: [PATCH] i386/x86_64: NMI watchdog: Remove spurious local_irq_enable() in check_nmi_watchdog()

There appears to be a spurious local_irq_enable() in the
check_nmi_watchdog() of both i386 and x86_64, I cannot see
when are interrupts being disabled before it. In fact we
seem to be allocating with GFP_KERNEL and calling
smp_call_function() just before this call, which suggests
this call to local_irq_enable() is spurious and can be
removed.

Signed-off-by: Satyam Sharma <ssatyam@....iitk.ac.in>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: Andi Kleen <ak@...e.de>

---

 arch/i386/kernel/nmi.c   |    1 -
 arch/x86_64/kernel/nmi.c |    1 -
 2 files changed, 2 deletions(-)

---

diff -ruNp a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c
--- a/arch/i386/kernel/nmi.c	2007-06-07 12:46:34.000000000 +0530
+++ b/arch/i386/kernel/nmi.c	2007-06-07 15:37:57.000000000 +0530
@@ -94,7 +94,6 @@ static int __init check_nmi_watchdog(voi

 	for_each_possible_cpu(cpu)
 		prev_nmi_count[cpu] = per_cpu(irq_stat, cpu).__nmi_count;
-	local_irq_enable();
 	mdelay((20*1000)/nmi_hz); // wait 20 ticks

 	for_each_possible_cpu(cpu) {
diff -ruNp a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c
--- a/arch/x86_64/kernel/nmi.c	2007-06-07 12:46:39.000000000 +0530
+++ b/arch/x86_64/kernel/nmi.c	2007-06-07 15:34:19.000000000 +0530
@@ -104,7 +104,6 @@ int __init check_nmi_watchdog (void)

 	for (cpu = 0; cpu < NR_CPUS; cpu++)
 		counts[cpu] = cpu_pda(cpu)->__nmi_count;
-	local_irq_enable();
 	mdelay((20*1000)/nmi_hz); // wait 20 ticks

 	for_each_online_cpu(cpu) {
-
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