[tip:irq/numa] x86/irq: change MSI irq_desc to be more numa aware

From: tip-bot for Yinghai Lu
Date: Fri May 01 2009 - 13:09:53 EST


Commit-ID: d047f53a2ecce37e3bdf79eac5a326fbaadb3628
Gitweb: http://git.kernel.org/tip/d047f53a2ecce37e3bdf79eac5a326fbaadb3628
Author: Yinghai Lu <yinghai@xxxxxxxxxx>
AuthorDate: Mon, 27 Apr 2009 18:02:23 -0700
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Tue, 28 Apr 2009 12:21:18 +0200

x86/irq: change MSI irq_desc to be more numa aware

Try to get irq_desc on the home node in create_irq_nr().

v2: don't check if we can move it when sparse_irq is not used
v3: use move_irq_des, if that node is not what we want

[ Impact: optimization, make MSI IRQ descriptors more NUMA aware ]

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
LKML-Reference: <49F6559F.7070005@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>


---
arch/x86/kernel/apic/io_apic.c | 17 +++++++++++++----
include/linux/irq.h | 2 +-
2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 82376e0..9cd4806 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -3172,14 +3172,13 @@ static int nr_irqs_gsi = NR_IRQS_LEGACY;
/*
* Dynamic irq allocate and deallocation
*/
-unsigned int create_irq_nr(unsigned int irq_want)
+unsigned int create_irq_nr(unsigned int irq_want, int node)
{
/* Allocate an unused irq */
unsigned int irq;
unsigned int new;
unsigned long flags;
struct irq_cfg *cfg_new = NULL;
- int node = cpu_to_node(boot_cpu_id);
struct irq_desc *desc_new = NULL;

irq = 0;
@@ -3197,6 +3196,13 @@ unsigned int create_irq_nr(unsigned int irq_want)

if (cfg_new->vector != 0)
continue;
+
+#ifdef CONFIG_NUMA_IRQ_DESC
+ /* different node ?*/
+ if (desc_new->node != node)
+ desc = move_irq_desc(desc, node);
+#endif
+
if (__assign_irq_vector(new, cfg_new, apic->target_cpus()) == 0)
irq = new;
break;
@@ -3214,11 +3220,12 @@ unsigned int create_irq_nr(unsigned int irq_want)

int create_irq(void)
{
+ int node = cpu_to_node(boot_cpu_id);
unsigned int irq_want;
int irq;

irq_want = nr_irqs_gsi;
- irq = create_irq_nr(irq_want);
+ irq = create_irq_nr(irq_want, node);

if (irq == 0)
irq = -1;
@@ -3476,15 +3483,17 @@ int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
unsigned int irq_want;
struct intel_iommu *iommu = NULL;
int index = 0;
+ int node;

/* x86 doesn't support multiple MSI yet */
if (type == PCI_CAP_ID_MSI && nvec > 1)
return 1;

+ node = dev_to_node(&dev->dev);
irq_want = nr_irqs_gsi;
sub_handle = 0;
list_for_each_entry(msidesc, &dev->msi_list, list) {
- irq = create_irq_nr(irq_want);
+ irq = create_irq_nr(irq_want, node);
if (irq == 0)
return -1;
irq_want = irq + 1;
diff --git a/include/linux/irq.h b/include/linux/irq.h
index a09baf8..4b95ddb 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -376,7 +376,7 @@ extern void set_irq_noprobe(unsigned int irq);
extern void set_irq_probe(unsigned int irq);

/* Handle dynamic irq creation and destruction */
-extern unsigned int create_irq_nr(unsigned int irq_want);
+extern unsigned int create_irq_nr(unsigned int irq_want, int node);
extern int create_irq(void);
extern void destroy_irq(unsigned int irq);

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