cpumask: make for_each_cpu_mask a bit smaller

The for_each_cpu_mask loop is used quite often in the kernel. It makes use of two functions: first_cpu and next_cpu. This patch changes for_each_cpu_mask to use only the latter. Because next_cpu finds the next eligible cpu _after_ the given one, the iteration variable has to be initialized to -1 and next_cpu has to be called with this value before the first iteration. An x86_64 defconfig kernel (from sched/latest) is about 2500 bytes smaller with this patch applied: text data bss dec hex filename 6222517 917952 749932 7890401 7865e1 vmlinux.orig 6219922 917952 749932 7887806 785bbe vmlinux The same size reduction is seen for defconfig+MAXSMP text data bss dec hex filename 6241772 2563968 1492716 10298456 9d2458 vmlinux.orig 6239211 2563968 1492716 10295895 9d1a57 vmlinux Signed-off-by: Alexander van Heukelum <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]>
kawasaki · May 23, 2008 · 7baac8b · 7baac8b
1 parent 3f9b48a
commit 7baac8b
Showing 1 changed file with 8 additions and 8 deletions.
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
@@ -370,10 +370,10 @@ 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) = first_cpu(mask);		\
-		(cpu) < NR_CPUS;		\
-		(cpu) = next_cpu((cpu), (mask)))
+#define for_each_cpu_mask(cpu, mask)			\
+	for ((cpu) = -1;				\
+		(cpu) = next_cpu((cpu), (mask)),	\
+		(cpu) < NR_CPUS; )
 #endif
 
 #if NR_CPUS <= 64
@@ -387,10 +387,10 @@ int __any_online_cpu(const cpumask_t *mask);
 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 for_each_cpu_mask_nr(cpu, mask)		\
-	for ((cpu) = first_cpu(mask);		\
-		(cpu) < nr_cpu_ids;		\
-		(cpu) = next_cpu_nr((cpu), (mask)))
+#define for_each_cpu_mask_nr(cpu, mask)			\
+	for ((cpu) = -1;				\
+		(cpu) = next_cpu_nr((cpu), (mask)),	\
+		(cpu) < nr_cpu_ids; )
 
 #endif /* NR_CPUS > 64 */