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Subject[PATCH 03/35] cpumask: add for_each_cpu_mask_and function
Add for_each_cpu_mask_and() function to eliminate need for a common use
of a temporary cpumask_t variable. When the following procedure is being
used:

funcproto(const cpumask_t *mask, ...)
{
cpumask_t temp;
cpus_and(temp, mask, cpu_online_map);
for_each_cpu_mask(cpu, temp)
...
It then becomes:

funcproto(cpumask_t *mask, ...)
{
for_each_cpu_mask_and(cpu, *mask, cpu_online_map)
...
... eliminating the need for the temp cpumask.


Applies to linux-2.6.tip/master.

Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
---
include/linux/cpumask.h | 33 ++++++++++++++++++++++++---------
lib/cpumask.c | 9 +++++++++
2 files changed, 33 insertions(+), 9 deletions(-)
--- test-compile.orig/include/linux/cpumask.h
+++ test-compile/include/linux/cpumask.h
@@ -109,6 +109,7 @@
*
* for_each_cpu_mask(cpu, mask) for-loop cpu over mask using NR_CPUS
* for_each_cpu_mask_nr(cpu, mask) for-loop cpu over mask using nr_cpu_ids
+ * for_each_cpu_mask_and(cpu, mask, and) for-loop cpu over (mask & and).
*
* int num_online_cpus() Number of online CPUs
* int num_possible_cpus() Number of all possible CPUs
@@ -400,29 +401,41 @@ static inline void __cpus_fold(cpumask_t

#if NR_CPUS == 1

-#define nr_cpu_ids 1
-#define first_cpu(src) ({ (void)(src); 0; })
-#define next_cpu(n, src) ({ (void)(src); 1; })
-#define any_online_cpu(mask) 0
-#define for_each_cpu_mask(cpu, mask) \
+#define nr_cpu_ids 1
+#define first_cpu(src) ({ (void)(src); 0; })
+#define next_cpu(n, src) ({ (void)(src); 1; })
+#define cpumask_next_and(n, srcp, andp) ({ (void)(srcp), (void)(andp); 1; })
+#define any_online_cpu(mask) 0
+
+#define for_each_cpu_mask(cpu, mask) \
for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
+#define for_each_cpu_mask_and(cpu, mask, and) \
+ for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)and)

#else /* NR_CPUS > 1 */

extern int nr_cpu_ids;
int __first_cpu(const cpumask_t *srcp);
int __next_cpu(int n, const cpumask_t *srcp);
+int cpumask_next_and(int n, const cpumask_t *srcp, const cpumask_t *andp);
int __any_online_cpu(const cpumask_t *mask);

#define first_cpu(src) __first_cpu(&(src))
#define next_cpu(n, src) __next_cpu((n), &(src))
#define any_online_cpu(mask) __any_online_cpu(&(mask))
+
#define for_each_cpu_mask(cpu, mask) \
for ((cpu) = -1; \
(cpu) = next_cpu((cpu), (mask)), \
- (cpu) < NR_CPUS; )
+ (cpu) < NR_CPUS;)
+#define for_each_cpu_mask_and(cpu, mask, and) \
+ for ((cpu) = -1; \
+ (cpu) = cpumask_next_and((cpu), &(mask), &(and)), \
+ (cpu) < nr_cpu_ids;)
#endif

+#define cpumask_first_and(mask, and) cpumask_next_and(-1, (mask), (and))
+
#if NR_CPUS <= 64

#define next_cpu_nr(n, src) next_cpu(n, src)
@@ -432,12 +445,14 @@ int __any_online_cpu(const cpumask_t *ma
#else /* NR_CPUS > 64 */

int __next_cpu_nr(int n, const cpumask_t *srcp);
-#define next_cpu_nr(n, src) __next_cpu_nr((n), &(src))
-#define cpus_weight_nr(cpumask) __cpus_weight(&(cpumask), nr_cpu_ids)
+
+#define next_cpu_nr(n, src) __next_cpu_nr((n), &(src))
+#define cpus_weight_nr(cpumask) __cpus_weight(&(cpumask), nr_cpu_ids)
+
#define for_each_cpu_mask_nr(cpu, mask) \
for ((cpu) = -1; \
(cpu) = next_cpu_nr((cpu), (mask)), \
- (cpu) < nr_cpu_ids; )
+ (cpu) < nr_cpu_ids;)

#endif /* NR_CPUS > 64 */

--- test-compile.orig/lib/cpumask.c
+++ test-compile/lib/cpumask.c
@@ -15,6 +15,15 @@ int __next_cpu(int n, const cpumask_t *s
}
EXPORT_SYMBOL(__next_cpu);

+int cpumask_next_and(int n, const cpumask_t *srcp, const cpumask_t *andp)
+{
+ while ((n = next_cpu_nr(n, *srcp)) < nr_cpu_ids)
+ if (cpu_isset(n, *andp))
+ break;
+ return n;
+}
+EXPORT_SYMBOL(cpumask_next_and);
+
#if NR_CPUS > 64
int __next_cpu_nr(int n, const cpumask_t *srcp)
{
--


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