irq: optimize init_kstat_irqs/init_copy_kstat_irqs
Yinghai Lu [Mon, 9 Feb 2009 00:18:03 +0000 (16:18 -0800)]
Simplify and make init_kstat_irqs etc more type proof, suggested by
Andrew.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/irq/handle.c
kernel/irq/numa_migrate.c

index 1b473e7..49d642b 100644 (file)
@@ -71,19 +71,21 @@ static struct irq_desc irq_desc_init = {
 
 void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr)
 {
-       unsigned long bytes;
-       char *ptr;
        int node;
-
-       /* Compute how many bytes we need per irq and allocate them */
-       bytes = nr * sizeof(unsigned int);
+       void *ptr;
 
        node = cpu_to_node(cpu);
-       ptr = kzalloc_node(bytes, GFP_ATOMIC, node);
-       printk(KERN_DEBUG "  alloc kstat_irqs on cpu %d node %d\n", cpu, node);
+       ptr = kzalloc_node(nr * sizeof(*desc->kstat_irqs), GFP_ATOMIC, node);
 
-       if (ptr)
-               desc->kstat_irqs = (unsigned int *)ptr;
+       /*
+        * don't overwite if can not get new one
+        * init_copy_kstat_irqs() could still use old one
+        */
+       if (ptr) {
+               printk(KERN_DEBUG "  alloc kstat_irqs on cpu %d node %d\n",
+                        cpu, node);
+               desc->kstat_irqs = ptr;
+       }
 }
 
 static void init_one_irq_desc(int irq, struct irq_desc *desc, int cpu)
index ecf765c..c500cfe 100644 (file)
@@ -17,16 +17,11 @@ 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);
-       }
+       if (desc->kstat_irqs != old_desc->kstat_irqs)
+               memcpy(desc->kstat_irqs, old_desc->kstat_irqs,
+                        nr * sizeof(*desc->kstat_irqs));
 }
 
 static void free_kstat_irqs(struct irq_desc *old_desc, struct irq_desc *desc)