[ 3.5.y.z extended stable ] Patch "x86: Eliminate irq_mis_count counted in arch_irq_stat" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    x86: Eliminate irq_mis_count counted in arch_irq_stat

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 7fed304cba758bd5cc309e23010f7d824918fd10 Mon Sep 17 00:00:00 2001
From: Li Fei <fei.li at intel.com>
Date: Fri, 26 Apr 2013 20:50:11 +0800
Subject: [PATCH] x86: Eliminate irq_mis_count counted in arch_irq_stat

commit f7b0e1055574ce06ab53391263b4e205bf38daf3 upstream.

With the current implementation, kstat_cpu(cpu).irqs_sum is also
increased in case of irq_mis_count increment.

So there is no need to count irq_mis_count in arch_irq_stat,
otherwise irq_mis_count will be counted twice in the sum of
/proc/stat.

Reported-by: Liu Chuansheng <chuansheng.liu at intel.com>
Signed-off-by: Li Fei <fei.li at intel.com>
Acked-by: Liu Chuansheng <chuansheng.liu at intel.com>
Cc: tomoki.sekiyama.qu at hitachi.com
Cc: joe at perches.com
Link: http://lkml.kernel.org/r/1366980611.32469.7.camel@fli24-HP-Compaq-8100-Elite-CMT-PC
Signed-off-by: Ingo Molnar <mingo at kernel.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/x86/kernel/irq.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 3dafc60..a14a835 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -165,10 +165,6 @@ u64 arch_irq_stat_cpu(unsigned int cpu)
 u64 arch_irq_stat(void)
 {
 	u64 sum = atomic_read(&irq_err_count);
-
-#ifdef CONFIG_X86_IO_APIC
-	sum += atomic_read(&irq_mis_count);
-#endif
 	return sum;
 }

--
1.8.1.2