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>
diff --git a/include/linux/irq.h b/include/linux/irq.h
index f899b50..fa27210 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -182,11 +182,11 @@
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 @@
#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 */