cpumask: Provide a generic set of CPUMASK_ALLOC macros
* Provide a generic set of CPUMASK_ALLOC macros patterned after the
SCHED_CPUMASK_ALLOC macros. This is used where multiple cpumask_t
variables are declared on the stack to reduce the amount of stack
space required.
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 2dbd9a2..72f9c32 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -75,6 +75,17 @@
* CPU_MASK_NONE Initializer - no bits set
* unsigned long *cpus_addr(mask) Array of unsigned long's in mask
*
+ *if NR_CPUS > BITS_PER_LONG
+ * CPUMASK_ALLOC(m) Declares and allocates struct m *m =
+ * (struct m *)kmalloc(sizeof(*m), ...)
+ * CPUMASK_FREE(m) Macro for kfree(v)
+ *else
+ * CPUMASK_ALLOC(m) Declares struct m _m, *m = &_m
+ * CPUMASK_FREE(m) Nop
+ *endif
+ * CPUMASK_VAR(v, m) Declares cpumask_t *v =
+ * m + offset(struct m, v)
+ *
* int cpumask_scnprintf(buf, len, mask) Format cpumask for printing
* int cpumask_parse_user(ubuf, ulen, mask) Parse ascii string as cpumask
* int cpulist_scnprintf(buf, len, mask) Format cpumask as list for printing
@@ -311,6 +322,16 @@
#define cpus_addr(src) ((src).bits)
+#if NR_CPUS > BITS_PER_LONG
+#define CPUMASK_ALLOC(m) struct m *m = kmalloc(sizeof(*m), GFP_KERNEL)
+#define CPUMASK_FREE(m) kfree(m)
+#else
+#define CPUMASK_ALLOC(m) struct allmasks _m, *m = &_m
+#define CPUMASK_FREE(m)
+#endif
+#define CPUMASK_VAR(v, m) cpumask_t *v = (cpumask_t *) \
+ ((unsigned long)(m) + offsetof(struct m, v))
+
#define cpumask_scnprintf(buf, len, src) \
__cpumask_scnprintf((buf), (len), &(src), NR_CPUS)
static inline int __cpumask_scnprintf(char *buf, int len,