[PATCH 31/36] sparseirq: use radix_tree instead of ptrs array

Yinghai Lu
2010-01-21T06:31:33Z

use radix_tree irq_desc_tree instead of irq_desc_ptrs.

-v2: according to Eric and cyrill to use radix_tree_lookup_slot and radix_tree_replace_slot

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
kernel/irq/handle.c | 49 +++++++++++++++++++++++++------------------------
1 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 266f798..76d5a67 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -19,6 +19,7 @@
#include <linux/kernel_stat.h>
#include <linux/rculist.h>
#include <linux/hash.h>
+#include <linux/radix-tree.h>
#include <trace/events/irq.h>

#include "internals.h"
@@ -127,7 +128,26 @@ static void init_one_irq_desc(int irq, struct irq_desc *desc, int node)
*/
DEFINE_RAW_SPINLOCK(sparse_irq_lock);

-static struct irq_desc **irq_desc_ptrs __read_mostly;
+static RADIX_TREE(irq_desc_tree, GFP_ATOMIC);
+
+static void set_irq_desc(unsigned int irq, struct irq_desc *desc)
+{
+ radix_tree_insert(&irq_desc_tree, irq, desc);
+}
+
+struct irq_desc *irq_to_desc(unsigned int irq)
+{
+ return radix_tree_lookup(&irq_desc_tree, irq);
+}
+
+void replace_irq_desc(unsigned int irq, struct irq_desc *desc)
+{
+ void **ptr;
+
+ ptr = radix_tree_lookup_slot(&irq_desc_tree, irq);
+ if (ptr)
+ radix_tree_replace_slot(ptr, desc);
+}

static struct irq_desc irq_desc_legacy[NR_IRQS_LEGACY] __cacheline_aligned_in_smp = {
[0 ... NR_IRQS_LEGACY-1] = {
@@ -159,9 +179,6 @@ int __init early_irq_init(void)
legacy_count = ARRAY_SIZE(irq_desc_legacy);
node = first_online_node;

- /* allocate irq_desc_ptrs array based on nr_irqs */
- irq_desc_ptrs = kcalloc(nr_irqs, sizeof(void *), GFP_NOWAIT);
-
/* allocate based on nr_cpu_ids */
kstat_irqs_legacy = kzalloc_node(NR_IRQS_LEGACY * nr_cpu_ids *
sizeof(int), GFP_NOWAIT, node);
@@ -175,28 +192,12 @@ int __init early_irq_init(void)
lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
alloc_desc_masks(&desc[i], node, true);
init_desc_masks(&desc[i]);
- irq_desc_ptrs[i] = desc + i;
+ set_irq_desc(i, &desc[i]);
}

- for (i = legacy_count; i < nr_irqs; i++)
- irq_desc_ptrs[i] = NULL;
-
return arch_early_irq_init();
}

-struct irq_desc *irq_to_desc(unsigned int irq)
-{
- if (irq_desc_ptrs && irq < nr_irqs)
- return irq_desc_ptrs[irq];
-
- return NULL;
-}
-
-void replace_irq_desc(unsigned int irq, struct irq_desc *desc)
-{
- irq_desc_ptrs[irq] = desc;
-}
-
struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
{
struct irq_desc *desc;
@@ -208,14 +209,14 @@ struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
return NULL;
}

- desc = irq_desc_ptrs[irq];
+ desc = irq_to_desc(irq);
if (desc)
return desc;

raw_spin_lock_irqsave(&sparse_irq_lock, flags);

/* We have to check it to avoid races with another CPU */
- desc = irq_desc_ptrs[irq];
+ desc = irq_to_desc(irq);
if (desc)
goto out_unlock;

@@ -228,7 +229,7 @@ struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
}
init_one_irq_desc(irq, desc, node);

- irq_desc_ptrs[irq] = desc;
+ set_irq_desc(irq, desc);

out_unlock:
raw_spin_unlock_irqrestore(&sparse_irq_lock, flags);
--
1.6.4.2