From 0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac Mon Sep 17 00:00:00 2001
From: Yinghai Lu <yinghai@kernel.org>
Date: Fri, 5 Dec 2008 18:58:31 -0800
Subject: sparse irq_desc[] array: core kernel and x86 changes

Impact: new feature

Problem on distro kernels: irq_desc[NR_IRQS] takes megabytes of RAM with
NR_CPUS set to large values. The goal is to be able to scale up to much
larger NR_IRQS value without impacting the (important) common case.

To solve this, we generalize irq_desc[NR_IRQS] to an (optional) array of
irq_desc pointers.

When CONFIG_SPARSE_IRQ=y is used, we use kzalloc_node to get irq_desc,
this also makes the IRQ descriptors NUMA-local (to the site that calls
request_irq()).

This gets rid of the irq_cfg[] static array on x86 as well: irq_cfg now
uses desc->chip_data for x86 to store irq_cfg.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/irq.c | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'arch/x86/kernel/irq.c')

diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index d1d4dc52f649..3f1d9d18df67 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -118,6 +118,9 @@ int show_interrupts(struct seq_file *p, void *v)
 	}
 
 	desc = irq_to_desc(i);
+	if (!desc)
+		return 0;
+
 	spin_lock_irqsave(&desc->lock, flags);
 #ifndef CONFIG_SMP
 	any_count = kstat_irqs(i);
-- 
cgit v1.2.3


From c3d80000e3a812fe5a200d6bde755fbd7fa65481 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Tue, 23 Dec 2008 15:15:17 +0100
Subject: x86: export vector_used_by_percpu_irq

Impact: build fix

lguest can be built as a module and makes use of this new symbol:

ERROR: "vector_used_by_percpu_irq" [drivers/lguest/lg.ko] undefined!

export it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/irq.c | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'arch/x86/kernel/irq.c')

diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 3f1d9d18df67..bce53e1352a0 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -9,6 +9,7 @@
 #include <asm/apic.h>
 #include <asm/io_apic.h>
 #include <asm/smp.h>
+#include <asm/irq.h>
 
 atomic_t irq_err_count;
 
@@ -190,3 +191,5 @@ u64 arch_irq_stat(void)
 #endif
 	return sum;
 }
+
+EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);
-- 
cgit v1.2.3


From 6a02e71099a87d13f2aa49cb491b5bfb5e662fae Mon Sep 17 00:00:00 2001
From: Jaswinder Singh Rajput <jaswinder@infradead.org>
Date: Sun, 4 Jan 2009 16:22:17 +0530
Subject: x86: irq.c fix style problems

Impact: cleanup

Fix:

 WARNING: Use #include <linux/smp.h> instead of <asm/smp.h>

 total: 0 errors, 1 warnings

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/irq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'arch/x86/kernel/irq.c')

diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index bce53e1352a0..3973e2df7f87 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -5,10 +5,10 @@
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
 #include <linux/seq_file.h>
+#include <linux/smp.h>
 
 #include <asm/apic.h>
 #include <asm/io_apic.h>
-#include <asm/smp.h>
 #include <asm/irq.h>
 
 atomic_t irq_err_count;
-- 
cgit v1.2.3