[PATCH 1/5] cpumask: update irq_desc to use cpumask_var_t

From: Mike Travis
Date: Wed Jan 07 2009 - 15:00:33 EST

Impact: reduce memory usage, use new cpumask API.

Replace the affinity and pending_masks with cpumask_var_t's. This adds
to the significant size reduction done with the SPARSE_IRQS changes.

The added functions (init_alloc_desc_masks & init_copy_desc_masks) are
in the include file so they can be inlined (and optimized out for the
!CONFIG_CPUMASKS_OFFSTACK case.) [Naming chosen to be consistent with
the other init*irq functions, as well as the backwards arg declaration
of "from, to" instead of the more common "to, from" standard.]

Includes a slight change to the declaration of struct irq_desc to embed
the pending_mask within ifdef(CONFIG_SMP) to be consistent with other
references, and some small changes to Xen.

Tested: sparse/non-sparse/cpumask_offstack/non-cpumask_offstack/nonuma/nosmp on x86_64

Signed-off-by: Mike Travis <travis@xxxxxxx>
Cc: Chris Wright <chrisw@xxxxxxxxxxxx>
Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
Cc: virtualization@xxxxxxxxxxxxxx
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Cc: Yinghai Lu <yhlu.kernel@xxxxxxxxx>
---
arch/x86/kernel/io_apic.c | 20 +++++------
arch/x86/kernel/irq_32.c | 2 -
arch/x86/kernel/irq_64.c | 2 -
drivers/xen/events.c | 4 +-
include/linux/irq.h | 81 ++++++++++++++++++++++++++++++++++++++++++++--
kernel/irq/chip.c | 5 ++
kernel/irq/handle.c | 26 +++++++-------
kernel/irq/manage.c | 12 +++---
kernel/irq/migration.c | 12 +++---
kernel/irq/numa_migrate.c | 12 ++++++
kernel/irq/proc.c | 4 +-
11 files changed, 135 insertions(+), 45 deletions(-)

--- linux-2.6-for-ingo.orig/arch/x86/kernel/io_apic.c
+++ linux-2.6-for-ingo/arch/x86/kernel/io_apic.c
@@ -358,7 +358,7 @@ set_extra_move_desc(struct irq_desc *des

if (!cfg->move_in_progress) {
/* it means that domain is not changed */
- if (!cpumask_intersects(&desc->affinity, mask))
+ if (!cpumask_intersects(desc->affinity, mask))
cfg->move_desc_pending = 1;
}
}
@@ -581,9 +581,9 @@ set_desc_affinity(struct irq_desc *desc,
if (assign_irq_vector(irq, cfg, mask))
return BAD_APICID;

- cpumask_and(&desc->affinity, cfg->domain, mask);
+ cpumask_and(desc->affinity, cfg->domain, mask);
set_extra_move_desc(desc, mask);
- return cpu_mask_to_apicid_and(&desc->affinity, cpu_online_mask);
+ return cpu_mask_to_apicid_and(desc->affinity, cpu_online_mask);
}

static void
@@ -2385,7 +2385,7 @@ migrate_ioapic_irq_desc(struct irq_desc
if (cfg->move_in_progress)
send_cleanup_vector(cfg);

- cpumask_copy(&desc->affinity, mask);
+ cpumask_copy(desc->affinity, mask);
}

static int migrate_irq_remapped_level_desc(struct irq_desc *desc)
@@ -2407,11 +2407,11 @@ static int migrate_irq_remapped_level_de
}

/* everthing is clear. we have right of way */
- migrate_ioapic_irq_desc(desc, &desc->pending_mask);
+ migrate_ioapic_irq_desc(desc, desc->pending_mask);

ret = 0;
desc->status &= ~IRQ_MOVE_PENDING;
- cpumask_clear(&desc->pending_mask);
+ cpumask_clear(desc->pending_mask);

unmask:
unmask_IO_APIC_irq_desc(desc);
@@ -2436,7 +2436,7 @@ static void ir_irq_migration(struct work
continue;
}

- desc->chip->set_affinity(irq, &desc->pending_mask);
+ desc->chip->set_affinity(irq, desc->pending_mask);
spin_unlock_irqrestore(&desc->lock, flags);
}
}
@@ -2450,7 +2450,7 @@ static void set_ir_ioapic_affinity_irq_d
{
if (desc->status & IRQ_LEVEL) {
desc->status |= IRQ_MOVE_PENDING;
- cpumask_copy(&desc->pending_mask, mask);
+ cpumask_copy(desc->pending_mask, mask);
migrate_irq_remapped_level_desc(desc);
return;
}
@@ -2518,7 +2518,7 @@ static void irq_complete_move(struct irq

/* domain has not changed, but affinity did */
me = smp_processor_id();
- if (cpu_isset(me, desc->affinity)) {
+ if (cpumask_test_cpu(me, desc->affinity)) {
*descp = desc = move_irq_desc(desc, me);
/* get the new one */
cfg = desc->chip_data;
@@ -4041,7 +4041,7 @@ void __init setup_ioapic_dest(void)
*/
if (desc->status &
(IRQ_NO_BALANCING | IRQ_AFFINITY_SET))
- mask = &desc->affinity;
+ mask = desc->affinity;
else
mask = TARGET_CPUS;

--- linux-2.6-for-ingo.orig/arch/x86/kernel/irq_32.c
+++ linux-2.6-for-ingo/arch/x86/kernel/irq_32.c
@@ -248,7 +248,7 @@ void fixup_irqs(void)
if (irq == 2)
continue;

- affinity = &desc->affinity;
+ affinity = desc->affinity;
if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
printk("Breaking affinity for irq %i\n", irq);
affinity = cpu_all_mask;
--- linux-2.6-for-ingo.orig/arch/x86/kernel/irq_64.c
+++ linux-2.6-for-ingo/arch/x86/kernel/irq_64.c
@@ -100,7 +100,7 @@ void fixup_irqs(void)
/* interrupt's are disabled at this point */
spin_lock(&desc->lock);

- affinity = &desc->affinity;
+ affinity = desc->affinity;
if (!irq_has_action(irq) ||
cpumask_equal(affinity, cpu_online_mask)) {
spin_unlock(&desc->lock);
--- linux-2.6-for-ingo.orig/drivers/xen/events.c
+++ linux-2.6-for-ingo/drivers/xen/events.c
@@ -125,7 +125,7 @@ static void bind_evtchn_to_cpu(unsigned

BUG_ON(irq == -1);
#ifdef CONFIG_SMP
- irq_to_desc(irq)->affinity = cpumask_of_cpu(cpu);
+ cpumask_copy(irq_to_desc(irq)->affinity, cpumask_of(cpu));
#endif

__clear_bit(chn, cpu_evtchn_mask[cpu_evtchn[chn]]);
@@ -142,7 +142,7 @@ static void init_evtchn_cpu_bindings(voi

/* By default all event channels notify CPU#0. */
for_each_irq_desc(i, desc) {
- desc->affinity = cpumask_of_cpu(0);
+ cpumask_copy(desc->affinity, cpumask_of(0));
}
#endif

--- linux-2.6-for-ingo.orig/include/linux/irq.h
+++ linux-2.6-for-ingo/include/linux/irq.h
@@ -182,11 +182,11 @@ struct irq_desc {
unsigned int irqs_unhandled;
spinlock_t lock;
#ifdef CONFIG_SMP
- cpumask_t affinity;
+ cpumask_var_t affinity;
unsigned int cpu;
-#endif
#ifdef CONFIG_GENERIC_PENDING_IRQ
- cpumask_t pending_mask;
+ cpumask_var_t pending_mask;
+#endif
#endif
#ifdef CONFIG_PROC_FS
struct proc_dir_entry *dir;
@@ -422,4 +422,79 @@ extern int set_irq_msi(unsigned int irq,

#endif /* !CONFIG_S390 */

+#ifdef CONFIG_SMP
+/**
+ * init_alloc_desc_masks - allocate cpumasks for irq_desc
+ * @desc: pointer to irq_desc struct
+ * @boot: true if need bootmem
+ *
+ * Allocates affinity and pending_mask cpumask if required.
+ * Returns true if successful (or not required).
+ * Side effect: affinity has all bits set, pending_mask has all bits clear.
+ */
+static inline bool init_alloc_desc_masks(struct irq_desc *desc, int node,
+ bool boot)
+{
+ if (boot) {
+ alloc_bootmem_cpumask_var(&desc->affinity);
+ cpumask_setall(desc->affinity);
+
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+ alloc_bootmem_cpumask_var(&desc->pending_mask);
+ cpumask_clear(desc->pending_mask);
+#endif
+ return true;
+ }
+
+ if (!alloc_cpumask_var_node(&desc->affinity, GFP_ATOMIC, node))
+ return false;
+ cpumask_setall(desc->affinity);
+
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+ if (!alloc_cpumask_var_node(&desc->pending_mask, GFP_ATOMIC, node)) {
+ free_cpumask_var(desc->affinity);
+ return false;
+ }
+ cpumask_clear(desc->pending_mask);
+#endif
+ return true;
+}
+
+/**
+ * init_copy_desc_masks - copy cpumasks for irq_desc
+ * @old_desc: pointer to old irq_desc struct
+ * @new_desc: pointer to new irq_desc struct
+ *
+ * Insures affinity and pending_masks are copied to new irq_desc.
+ * If !CONFIG_CPUMASKS_OFFSTACK the cpumasks are embedded in the
+ * irq_desc struct so the copy is redundant.
+ */
+
+static inline void init_copy_desc_masks(struct irq_desc *old_desc,
+ struct irq_desc *new_desc)
+{
+#ifdef CONFIG_CPUMASKS_OFFSTACK
+ cpumask_copy(new_desc->affinity, old_desc->affinity);
+
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+ cpumask_copy(new_desc->pending_mask, old_desc->pending_mask);
+#endif
+#endif
+}
+
+#else /* !CONFIG_SMP */
+
+static inline bool init_alloc_desc_masks(struct irq_desc *desc, int node,
+ bool boot)
+{
+ return true;
+}
+
+static inline void init_copy_desc_masks(struct irq_desc *old_desc,
+ struct irq_desc *new_desc)
+{
+}
+
+#endif /* CONFIG_SMP */
+
#endif /* _LINUX_IRQ_H */
--- linux-2.6-for-ingo.orig/kernel/irq/chip.c
+++ linux-2.6-for-ingo/kernel/irq/chip.c
@@ -46,7 +46,10 @@ void dynamic_irq_init(unsigned int irq)
desc->irq_count = 0;
desc->irqs_unhandled = 0;
#ifdef CONFIG_SMP
- cpumask_setall(&desc->affinity);
+ cpumask_setall(desc->affinity);
+#ifdef CONFIG_GENERIC_PENDING_IRQ
+ cpumask_clear(desc->pending_mask);
+#endif
#endif
spin_unlock_irqrestore(&desc->lock, flags);
}
--- linux-2.6-for-ingo.orig/kernel/irq/handle.c
+++ linux-2.6-for-ingo/kernel/irq/handle.c
@@ -64,9 +64,6 @@ static struct irq_desc irq_desc_init = {
.handle_irq = handle_bad_irq,
.depth = 1,
.lock = __SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
-#ifdef CONFIG_SMP
- .affinity = CPU_MASK_ALL
-#endif
};

void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr)
@@ -88,6 +85,8 @@ void init_kstat_irqs(struct irq_desc *de

static void init_one_irq_desc(int irq, struct irq_desc *desc, int cpu)
{
+ int node = cpu_to_node(cpu);
+
memcpy(desc, &irq_desc_init, sizeof(struct irq_desc));

spin_lock_init(&desc->lock);
@@ -101,6 +100,10 @@ static void init_one_irq_desc(int irq, s
printk(KERN_ERR "can not alloc kstat_irqs\n");
BUG_ON(1);
}
+ if (!init_alloc_desc_masks(desc, node, false)) {
+ printk(KERN_ERR "can not alloc irq_desc cpumasks\n");
+ BUG_ON(1);
+ }
arch_init_chip_data(desc, cpu);
}

@@ -119,9 +122,6 @@ static struct irq_desc irq_desc_legacy[N
.handle_irq = handle_bad_irq,
.depth = 1,
.lock = __SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
-#ifdef CONFIG_SMP
- .affinity = CPU_MASK_ALL
-#endif
}
};

@@ -141,7 +141,7 @@ int __init early_irq_init(void)
desc[i].irq = i;
desc[i].kstat_irqs = kstat_irqs_legacy[i];
lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
-
+ init_alloc_desc_masks(&desc[i], 0, true);
irq_desc_ptrs[i] = desc + i;
}

@@ -188,6 +188,10 @@ struct irq_desc *irq_to_desc_alloc_cpu(u
printk(KERN_ERR "can not alloc irq_desc\n");
BUG_ON(1);
}
+ if (!init_alloc_desc_masks(desc, node, false)) {
+ printk(KERN_ERR "can not alloc irq_desc cpumasks\n");
+ BUG_ON(1);
+ }
init_one_irq_desc(irq, desc, cpu);

irq_desc_ptrs[irq] = desc;
@@ -207,9 +211,6 @@ struct irq_desc irq_desc[NR_IRQS] __cach
.handle_irq = handle_bad_irq,
.depth = 1,
.lock = __SPIN_LOCK_UNLOCKED(irq_desc->lock),
-#ifdef CONFIG_SMP
- .affinity = CPU_MASK_ALL
-#endif
}
};

@@ -222,9 +223,10 @@ int __init early_irq_init(void)
desc = irq_desc;
count = ARRAY_SIZE(irq_desc);

- for (i = 0; i < count; i++)
+ for (i = 0; i < count; i++) {
desc[i].irq = i;
-
+ init_alloc_desc_masks(&desc[i], 0, true);
+ }
return arch_early_irq_init();
}

--- linux-2.6-for-ingo.orig/kernel/irq/manage.c
+++ linux-2.6-for-ingo/kernel/irq/manage.c
@@ -98,14 +98,14 @@ int irq_set_affinity(unsigned int irq, c

#ifdef CONFIG_GENERIC_PENDING_IRQ
if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) {
- cpumask_copy(&desc->affinity, cpumask);
+ cpumask_copy(desc->affinity, cpumask);
desc->chip->set_affinity(irq, cpumask);
} else {
desc->status |= IRQ_MOVE_PENDING;
- cpumask_copy(&desc->pending_mask, cpumask);
+ cpumask_copy(desc->pending_mask, cpumask);
}
#else
- cpumask_copy(&desc->affinity, cpumask);
+ cpumask_copy(desc->affinity, cpumask);
desc->chip->set_affinity(irq, cpumask);
#endif
desc->status |= IRQ_AFFINITY_SET;
@@ -127,16 +127,16 @@ int do_irq_select_affinity(unsigned int
* one of the targets is online.
*/
if (desc->status & (IRQ_AFFINITY_SET | IRQ_NO_BALANCING)) {
- if (cpumask_any_and(&desc->affinity, cpu_online_mask)
+ if (cpumask_any_and(desc->affinity, cpu_online_mask)
< nr_cpu_ids)
goto set_affinity;
else
desc->status &= ~IRQ_AFFINITY_SET;
}

- cpumask_and(&desc->affinity, cpu_online_mask, irq_default_affinity);
+ cpumask_and(desc->affinity, cpu_online_mask, irq_default_affinity);
set_affinity:
- desc->chip->set_affinity(irq, &desc->affinity);
+ desc->chip->set_affinity(irq, desc->affinity);

return 0;
}
--- linux-2.6-for-ingo.orig/kernel/irq/migration.c
+++ linux-2.6-for-ingo/kernel/irq/migration.c
@@ -18,7 +18,7 @@ void move_masked_irq(int irq)

desc->status &= ~IRQ_MOVE_PENDING;

- if (unlikely(cpumask_empty(&desc->pending_mask)))
+ if (unlikely(cpumask_empty(desc->pending_mask)))
return;

if (!desc->chip->set_affinity)
@@ -38,13 +38,13 @@ void move_masked_irq(int irq)
* For correct operation this depends on the caller
* masking the irqs.
*/
- if (likely(cpumask_any_and(&desc->pending_mask, cpu_online_mask)
+ if (likely(cpumask_any_and(desc->pending_mask, cpu_online_mask)
< nr_cpu_ids)) {
- cpumask_and(&desc->affinity,
- &desc->pending_mask, cpu_online_mask);
- desc->chip->set_affinity(irq, &desc->affinity);
+ cpumask_and(desc->affinity,
+ desc->pending_mask, cpu_online_mask);
+ desc->chip->set_affinity(irq, desc->affinity);
}
- cpumask_clear(&desc->pending_mask);
+ cpumask_clear(desc->pending_mask);
}

void move_native_irq(int irq)
--- linux-2.6-for-ingo.orig/kernel/irq/numa_migrate.c
+++ linux-2.6-for-ingo/kernel/irq/numa_migrate.c
@@ -46,6 +46,7 @@ static void init_copy_one_irq_desc(int i
desc->cpu = cpu;
lockdep_set_class(&desc->lock, &irq_desc_lock_class);
init_copy_kstat_irqs(old_desc, desc, cpu, nr_cpu_ids);
+ init_copy_desc_masks(old_desc, desc);
arch_init_copy_chip_data(old_desc, desc, cpu);
}

@@ -76,11 +77,20 @@ static struct irq_desc *__real_move_irq_
node = cpu_to_node(cpu);
desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
if (!desc) {
- printk(KERN_ERR "irq %d: can not get new irq_desc for migration.\n", irq);
+ printk(KERN_ERR "irq %d: can not get new irq_desc "
+ "for migration.\n", irq);
/* still use old one */
desc = old_desc;
goto out_unlock;
}
+ if (!init_alloc_desc_masks(desc, node, false)) {
+ printk(KERN_ERR "irq %d: can not get new irq_desc cpumask "
+ "for migration.\n", irq);
+ /* still use old one */
+ kfree(desc);
+ desc = old_desc;
+ goto out_unlock;
+ }
init_copy_one_irq_desc(irq, old_desc, desc, cpu);

irq_desc_ptrs[irq] = desc;
--- linux-2.6-for-ingo.orig/kernel/irq/proc.c
+++ linux-2.6-for-ingo/kernel/irq/proc.c
@@ -20,11 +20,11 @@ static struct proc_dir_entry *root_irq_d
static int irq_affinity_proc_show(struct seq_file *m, void *v)
{
struct irq_desc *desc = irq_to_desc((long)m->private);
- const struct cpumask *mask = &desc->affinity;
+ const struct cpumask *mask = desc->affinity;

#ifdef CONFIG_GENERIC_PENDING_IRQ
if (desc->status & IRQ_MOVE_PENDING)
- mask = &desc->pending_mask;
+ mask = desc->pending_mask;
#endif
seq_cpumask(m, mask);
seq_putc(m, '\n');

--
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