[PATCH] irq: move irq_desc according to smp_affinity v7

From: Yinghai Lu
Date: Thu Dec 11 2008 - 03:16:29 EST



impact: new feature move irq_desc with sparseirq

if CONFIG_NUMA_MIGRATE_IRQ_DESC is set
make irq_desc to go with affinity aka irq_desc moving etc
call move_irq_desc in irq_complete_move()
legacy irq_desc is not moved, because they are allocated via static array

v3: add calling to irq_to_desc after calling ack/eoi instead of passing desc

v6: use irq_remap_to_desc to avoid some #ifdef according to Ingo

for logical apic mode, need to add move_desc_in_progress_in_same_domain. otherwise it will not get moved. ==> also could need two phase to get irq_desc moved.
for example: 0xff is old affinity, and need to set 0xf, and then set to 0xf0.
[ or we need to change domain definition to cpus on the same node ? ]

LBSuse:~ # cat /proc/irq/22/smp_affinity
00000000,00000000,00000000,000000ff
LBSuse:~ # echo f > /proc/irq/22/smp_affinity
LBSuse:~ # cat /proc/irq/22/smp_affinity
00000000,00000000,00000000,0000000f
LBSuse:~ # tail /var/log/messages
...
Oct 27 12:35:34 LBSuse kernel: klogd 1.4.1, log source = /proc/kmsg started.
Oct 27 12:35:34 LBSuse kernel: eth0: no IPv6 routers present
LBSuse:~ # echo f0 > /proc/irq/22/smp_affinity
LBSuse:~ # tail /var/log/messages
Oct 27 12:35:34 LBSuse kernel: klogd 1.4.1, log source = /proc/kmsg started.
Oct 27 12:35:34 LBSuse kernel: eth0: no IPv6 routers present
Oct 27 12:36:46 LBSuse kernel: move irq_desc for 22 aka 0x16 to cpu 7 node 1
Oct 27 12:36:46 LBSuse kernel: alloc kstat_irqs on cpu 7 node 1
Oct 27 12:36:46 LBSuse kernel: alloc irq_cfg on cpu 7 node 1
Oct 27 12:36:46 LBSuse kernel: alloc irq_2_pin on cpu 7 node 1

so assume the user space program should update /proc/irq/XX/smp_affinity to 03 or 0f at first on boot
or we change irq_default_affinity ?

for physical apic is much simple
on 4 sockets 16 cores system
irq_desc is moving..
when
# echo 10 > /proc/irq/134483967/smp_affinity
# echo 100 > /proc/irq/134483967/smp_affinity
# echo 1000 > /proc/irq/134483967/smp_affinity
got
Nov 9 21:39:51 LBSuse kernel: move irq_desc for 134483967 aka 0x8040fff to cpu 4 node 1
Nov 9 21:39:51 LBSuse kernel: alloc kstat_irqs on cpu 4 node 1
Nov 9 21:39:51 LBSuse kernel: alloc irq_cfg on cpu 4 node 1
Nov 9 21:40:05 LBSuse kernel: move irq_desc for 134483967 aka 0x8040fff to cpu 8 node 2
Nov 9 21:40:05 LBSuse kernel: alloc kstat_irqs on cpu 8 node 2
Nov 9 21:40:05 LBSuse kernel: alloc irq_cfg on cpu 8 node 2
Nov 9 21:40:18 LBSuse kernel: move irq_desc for 134483967 aka 0x8040fff to cpu 12 node 3
Nov 9 21:40:18 LBSuse kernel: alloc kstat_irqs on cpu 12 node 3
Nov 9 21:40:18 LBSuse kernel: alloc irq_cfg on cpu 12 node 3

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>

---
arch/x86/Kconfig | 9 ++
arch/x86/kernel/io_apic.c | 142 +++++++++++++++++++++++++++++++++++++++++++++-
include/linux/irq.h | 10 +++
kernel/irq/Makefile | 1
kernel/irq/chip.c | 12 +++
kernel/irq/handle.c | 15 +++-
kernel/irq/internals.h | 5 +
kernel/irq/numa_migrate.c | 125 ++++++++++++++++++++++++++++++++++++++++
8 files changed, 311 insertions(+), 8 deletions(-)

Index: linux-2.6/arch/x86/Kconfig
===================================================================
--- linux-2.6.orig/arch/x86/Kconfig
+++ linux-2.6/arch/x86/Kconfig
@@ -253,6 +253,15 @@ config SPARSE_IRQ

If you don't know what to do here, say Y.

+config NUMA_MIGRATE_IRQ_DESC
+ bool "Move irq desc when changing irq smp_affinity"
+ depends on SPARSE_IRQ && SMP
+ default n
+ help
+ This enables moving irq_desc to cpu/node that irq will use handled.
+
+ If you don't know what to do here, say N.
+
config X86_FIND_SMP_CONFIG
def_bool y
depends on X86_MPPARSE || X86_VOYAGER
Index: linux-2.6/arch/x86/kernel/io_apic.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/io_apic.c
+++ linux-2.6/arch/x86/kernel/io_apic.c
@@ -141,6 +141,9 @@ struct irq_cfg {
unsigned move_cleanup_count;
u8 vector;
u8 move_in_progress : 1;
+#ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
+ u8 move_desc_pending : 1;
+#endif
};

/* irq_cfg is indexed by the sum of all RTEs in all I/O APICs. */
@@ -223,6 +226,121 @@ void arch_init_chip_data(struct irq_desc
}
}

+#ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
+
+static void
+init_copy_irq_2_pin(struct irq_cfg *old_cfg, struct irq_cfg *cfg, int cpu)
+{
+ struct irq_pin_list *old_entry, *head, *tail, *entry;
+
+ cfg->irq_2_pin = NULL;
+ old_entry = old_cfg->irq_2_pin;
+ if (!old_entry)
+ return;
+
+ entry = get_one_free_irq_2_pin(cpu);
+ if (!entry)
+ return;
+
+ entry->apic = old_entry->apic;
+ entry->pin = old_entry->pin;
+ head = entry;
+ tail = entry;
+ old_entry = old_entry->next;
+ while (old_entry) {
+ entry = get_one_free_irq_2_pin(cpu);
+ if (!entry) {
+ entry = head;
+ while (entry) {
+ head = entry->next;
+ kfree(entry);
+ entry = head;
+ }
+ /* still use the old one */
+ return;
+ }
+ entry->apic = old_entry->apic;
+ entry->pin = old_entry->pin;
+ tail->next = entry;
+ tail = entry;
+ old_entry = old_entry->next;
+ }
+
+ tail->next = NULL;
+ cfg->irq_2_pin = head;
+}
+
+static void free_irq_2_pin(struct irq_cfg *old_cfg, struct irq_cfg *cfg)
+{
+ struct irq_pin_list *entry, *next;
+
+ if (old_cfg->irq_2_pin == cfg->irq_2_pin)
+ return;
+
+ entry = old_cfg->irq_2_pin;
+
+ while (entry) {
+ next = entry->next;
+ kfree(entry);
+ entry = next;
+ }
+ old_cfg->irq_2_pin = NULL;
+}
+
+void arch_init_copy_chip_data(struct irq_desc *old_desc,
+ struct irq_desc *desc, int cpu)
+{
+ struct irq_cfg *cfg;
+ struct irq_cfg *old_cfg;
+
+ cfg = get_one_free_irq_cfg(cpu);
+
+ if (!cfg)
+ return;
+
+ desc->chip_data = cfg;
+
+ old_cfg = old_desc->chip_data;
+
+ memcpy(cfg, old_cfg, sizeof(struct irq_cfg));
+
+ init_copy_irq_2_pin(old_cfg, cfg, cpu);
+}
+
+static void free_irq_cfg(struct irq_cfg *old_cfg)
+{
+ kfree(old_cfg);
+}
+
+void arch_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc)
+{
+ struct irq_cfg *old_cfg, *cfg;
+
+ old_cfg = old_desc->chip_data;
+ cfg = desc->chip_data;
+
+ if (old_cfg == cfg)
+ return;
+
+ if (old_cfg) {
+ free_irq_2_pin(old_cfg, cfg);
+ free_irq_cfg(old_cfg);
+ old_desc->chip_data = NULL;
+ }
+}
+
+static void set_extra_move_desc(struct irq_desc *desc, cpumask_t mask)
+{
+ struct irq_cfg *cfg = desc->chip_data;
+
+ if (!cfg->move_in_progress) {
+ /* it means that domain is not changed */
+ if (!cpus_intersects(desc->affinity, mask))
+ cfg->move_desc_pending = 1;
+ }
+}
+#endif
+
#else
static struct irq_cfg *irq_cfg(unsigned int irq)
{
@@ -231,9 +349,11 @@ static struct irq_cfg *irq_cfg(unsigned

#endif

+#ifndef CONFIG_NUMA_MIGRATE_IRQ_DESC
static inline void set_extra_move_desc(struct irq_desc *desc, cpumask_t mask)
{
}
+#endif

struct io_apic {
unsigned int index;
@@ -2346,14 +2466,34 @@ static void irq_complete_move(struct irq
struct irq_cfg *cfg = desc->chip_data;
unsigned vector, me;

- if (likely(!cfg->move_in_progress))
+ if (likely(!cfg->move_in_progress)) {
+#ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
+ if (likely(!cfg->move_desc_pending))
+ return;
+
+ /* domain is not change, but affinity is changed */
+ me = smp_processor_id();
+ if (cpu_isset(me, desc->affinity)) {
+ *descp = desc = move_irq_desc(desc, me);
+ /* get the new one */
+ cfg = desc->chip_data;
+ cfg->move_desc_pending = 0;
+ }
+#endif
return;
+ }

vector = ~get_irq_regs()->orig_ax;
me = smp_processor_id();
if ((vector == cfg->vector) && cpu_isset(me, cfg->domain)) {
cpumask_t cleanup_mask;

+#ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
+ *descp = desc = move_irq_desc(desc, me);
+ /* get the new one */
+ cfg = desc->chip_data;
+#endif
+
cpus_and(cleanup_mask, cfg->old_domain, cpu_online_map);
cfg->move_cleanup_count = cpus_weight(cleanup_mask);
send_IPI_mask(cleanup_mask, IRQ_MOVE_CLEANUP_VECTOR);
Index: linux-2.6/kernel/irq/handle.c
===================================================================
--- linux-2.6.orig/kernel/irq/handle.c
+++ linux-2.6/kernel/irq/handle.c
@@ -23,7 +23,7 @@
/*
* lockdep: we want to handle all irq_desc locks as a single lock-class:
*/
-static struct lock_class_key irq_desc_lock_class;
+struct lock_class_key irq_desc_lock_class;

/**
* handle_bad_irq - handle spurious and unhandled irqs
@@ -73,7 +73,7 @@ static struct irq_desc irq_desc_init = {
#endif
};

-static void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr)
+void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr)
{
unsigned long bytes;
char *ptr;
@@ -113,7 +113,7 @@ static void init_one_irq_desc(int irq, s
/*
* Protect the sparse_irqs:
*/
-static DEFINE_SPINLOCK(sparse_irq_lock);
+DEFINE_SPINLOCK(sparse_irq_lock);

struct irq_desc *irq_desc_ptrs[NR_IRQS] __read_mostly;

@@ -337,8 +337,11 @@ unsigned int __do_IRQ(unsigned int irq)
/*
* No locking required for CPU-local interrupts:
*/
- if (desc->chip->ack)
+ if (desc->chip->ack) {
desc->chip->ack(irq);
+ /* get new one */
+ desc = irq_remap_to_desc(irq, desc);
+ }
if (likely(!(desc->status & IRQ_DISABLED))) {
action_ret = handle_IRQ_event(irq, desc->action);
if (!noirqdebug)
@@ -349,8 +352,10 @@ unsigned int __do_IRQ(unsigned int irq)
}

spin_lock(&desc->lock);
- if (desc->chip->ack)
+ if (desc->chip->ack) {
desc->chip->ack(irq);
+ desc = irq_remap_to_desc(irq, desc);
+ }
/*
* REPLAY is when Linux resends an IRQ that was dropped earlier
* WAITING is used by probe to mark irqs that are being tested
Index: linux-2.6/kernel/irq/chip.c
===================================================================
--- linux-2.6.orig/kernel/irq/chip.c
+++ linux-2.6/kernel/irq/chip.c
@@ -354,6 +354,7 @@ handle_level_irq(unsigned int irq, struc

spin_lock(&desc->lock);
mask_ack_irq(desc, irq);
+ desc = irq_remap_to_desc(irq, desc);

if (unlikely(desc->status & IRQ_INPROGRESS))
goto out_unlock;
@@ -431,6 +432,7 @@ handle_fasteoi_irq(unsigned int irq, str
desc->status &= ~IRQ_INPROGRESS;
out:
desc->chip->eoi(irq);
+ desc = irq_remap_to_desc(irq, desc);

spin_unlock(&desc->lock);
}
@@ -467,12 +469,14 @@ handle_edge_irq(unsigned int irq, struct
!desc->action)) {
desc->status |= (IRQ_PENDING | IRQ_MASKED);
mask_ack_irq(desc, irq);
+ desc = irq_remap_to_desc(irq, desc);
goto out_unlock;
}
kstat_incr_irqs_this_cpu(irq, desc);

/* Start handling the irq */
desc->chip->ack(irq);
+ desc = irq_remap_to_desc(irq, desc);

/* Mark the IRQ currently in progress.*/
desc->status |= IRQ_INPROGRESS;
@@ -533,8 +537,10 @@ handle_percpu_irq(unsigned int irq, stru
if (!noirqdebug)
note_interrupt(irq, desc, action_ret);

- if (desc->chip->eoi)
+ if (desc->chip->eoi) {
desc->chip->eoi(irq);
+ desc = irq_remap_to_desc(irq, desc);
+ }
}

void
@@ -569,8 +575,10 @@ __set_irq_handler(unsigned int irq, irq_

/* Uninstall? */
if (handle == handle_bad_irq) {
- if (desc->chip != &no_irq_chip)
+ if (desc->chip != &no_irq_chip) {
mask_ack_irq(desc, irq);
+ desc = irq_remap_to_desc(irq, desc);
+ }
desc->status |= IRQ_DISABLED;
desc->depth = 1;
}
Index: linux-2.6/include/linux/irq.h
===================================================================
--- linux-2.6.orig/include/linux/irq.h
+++ linux-2.6/include/linux/irq.h
@@ -227,6 +227,16 @@ extern struct irq_desc *move_irq_desc(st

#endif

+static inline struct irq_desc *
+irq_remap_to_desc(unsigned int irq, struct irq_desc *desc)
+{
+#ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
+ return irq_to_desc(irq);
+#else
+ return desc;
+#endif
+}
+
/*
* Migration helpers for obsolete names, they will go away:
*/
Index: linux-2.6/kernel/irq/numa_migrate.c
===================================================================
--- /dev/null
+++ linux-2.6/kernel/irq/numa_migrate.c
@@ -0,0 +1,127 @@
+/*
+ * linux/kernel/irq/handle.c
+ *
+ * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
+ * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
+ *
+ * This file contains the core interrupt handling code.
+ *
+ * Detailed information is available in Documentation/DocBook/genericirq
+ *
+ */
+
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+
+#include "internals.h"
+
+static void init_copy_kstat_irqs(struct irq_desc *old_desc,
+ struct irq_desc *desc,
+ int cpu, int nr)
+{
+ unsigned long bytes;
+
+ init_kstat_irqs(desc, cpu, nr);
+
+ if (desc->kstat_irqs != old_desc->kstat_irqs) {
+ /* Compute how many bytes we need per irq and allocate them */
+ bytes = nr * sizeof(unsigned int);
+
+ memcpy(desc->kstat_irqs, old_desc->kstat_irqs, bytes);
+ }
+}
+
+static void free_kstat_irqs(struct irq_desc *old_desc, struct irq_desc *desc)
+{
+ if (old_desc->kstat_irqs == desc->kstat_irqs)
+ return;
+
+ kfree(old_desc->kstat_irqs);
+ old_desc->kstat_irqs = NULL;
+}
+
+static void init_copy_one_irq_desc(int irq, struct irq_desc *old_desc,
+ struct irq_desc *desc, int cpu)
+{
+ memcpy(desc, old_desc, sizeof(struct irq_desc));
+ desc->cpu = cpu;
+ lockdep_set_class(&desc->lock, &irq_desc_lock_class);
+ init_copy_kstat_irqs(old_desc, desc, cpu, nr_cpu_ids);
+ arch_init_copy_chip_data(old_desc, desc, cpu);
+}
+
+static void free_one_irq_desc(struct irq_desc *old_desc, struct irq_desc *desc)
+{
+ free_kstat_irqs(old_desc, desc);
+ arch_free_chip_data(old_desc, desc);
+}
+
+static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
+ int cpu)
+{
+ struct irq_desc *desc;
+ unsigned int irq;
+ unsigned long flags;
+ int node;
+
+ irq = old_desc->irq;
+
+ spin_lock_irqsave(&sparse_irq_lock, flags);
+
+ /* We have to check it to avoid races with another CPU */
+ desc = irq_desc_ptrs[irq];
+
+ if (desc && old_desc != desc)
+ goto out_unlock;
+
+ node = cpu_to_node(cpu);
+ desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
+ printk(KERN_DEBUG " move irq_desc for %d to cpu %d node %d\n",
+ irq, cpu, node);
+ if (!desc) {
+ printk(KERN_ERR "can not get new irq_desc for moving\n");
+ /* still use old one */
+ desc = old_desc;
+ goto out_unlock;
+ }
+ init_copy_one_irq_desc(irq, old_desc, desc, cpu);
+
+ irq_desc_ptrs[irq] = desc;
+
+ /* free the old one */
+ free_one_irq_desc(old_desc, desc);
+ kfree(old_desc);
+
+out_unlock:
+ spin_unlock_irqrestore(&sparse_irq_lock, flags);
+
+ return desc;
+}
+
+struct irq_desc *move_irq_desc(struct irq_desc *desc, int cpu)
+{
+ int old_cpu;
+ int node, old_node;
+
+ /* those all static, do move them */
+ if (desc->irq < NR_IRQS_LEGACY)
+ return desc;
+
+ old_cpu = desc->cpu;
+ printk(KERN_DEBUG
+ "try to move irq_desc from cpu %d to %d\n", old_cpu, cpu);
+ if (old_cpu != cpu) {
+ node = cpu_to_node(cpu);
+ old_node = cpu_to_node(old_cpu);
+ if (old_node != node)
+ desc = __real_move_irq_desc(desc, cpu);
+ else
+ desc->cpu = cpu;
+ }
+
+ return desc;
+}
+
Index: linux-2.6/kernel/irq/Makefile
===================================================================
--- linux-2.6.orig/kernel/irq/Makefile
+++ linux-2.6/kernel/irq/Makefile
@@ -3,3 +3,4 @@ obj-y := handle.o manage.o spurious.o re
obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o
obj-$(CONFIG_PROC_FS) += proc.o
obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o
+obj-$(CONFIG_NUMA_MIGRATE_IRQ_DESC) += numa_migrate.o
Index: linux-2.6/kernel/irq/internals.h
===================================================================
--- linux-2.6.orig/kernel/irq/internals.h
+++ linux-2.6/kernel/irq/internals.h
@@ -13,6 +13,11 @@ extern void compat_irq_chip_set_default_
extern int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
unsigned long flags);

+extern struct lock_class_key irq_desc_lock_class;
+extern void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr);
+extern spinlock_t sparse_irq_lock;
+extern struct irq_desc *irq_desc_ptrs[NR_IRQS];
+
#ifdef CONFIG_PROC_FS
extern void register_irq_proc(unsigned int irq, struct irq_desc *desc);
extern void register_handler_proc(unsigned int irq, struct irqaction *action);

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