cpumask: update irq_desc to use cpumask_var_t

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@sgi.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: virtualization@lists.osdl.org
Cc: xen-devel@lists.xensource.com
Cc: Yinghai Lu <yhlu.kernel@gmail.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/kernel/irq/numa_migrate.c b/kernel/irq/numa_migrate.c
index ecf765c6a77a..f001a4ea6414 100644
--- a/kernel/irq/numa_migrate.c
+++ b/kernel/irq/numa_migrate.c
@@ -46,6 +46,7 @@ static void init_copy_one_irq_desc(int irq, struct irq_desc *old_desc,
         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_desc(struct irq_desc *old_desc,
         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;