[PATCH 4/4] cpumask: Rename 'alloc_cpumask_var_node()' to '__alloc_cpumask_var_node()'

From: Ingo Molnar
Date: Mon Dec 07 2015 - 03:50:41 EST


Add a double underscore to this API, to make it very clear that this is an
internal API with unusual semantics: for example on !CPUMASK_OFFSTACK
kernels it will result in initialized cpumasks, while on CPUMASK_OFFSTACK
kernels it will allocate a var-cpumask that is not initialized. The
caller has to make sure this initialization happens.

Also add this information to the documentation of the API.

Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
include/linux/cpumask.h | 4 ++--
lib/cpumask.c | 16 ++++++++++------
2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 719fecaa64e4..7ed1e1f8e806 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -653,7 +653,7 @@ typedef struct cpumask *cpumask_var_t;

#define this_cpu_cpumask_var_ptr(x) this_cpu_read(x)

-bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
+bool __alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
void zalloc_bootmem_cpumask_var(cpumask_var_t *mask);
@@ -665,7 +665,7 @@ typedef struct cpumask cpumask_var_t[1];

#define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x)

-static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
+static inline bool __alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
int node)
{
return true;
diff --git a/lib/cpumask.c b/lib/cpumask.c
index cb9b80284274..c291d993fb9c 100644
--- a/lib/cpumask.c
+++ b/lib/cpumask.c
@@ -45,7 +45,7 @@ int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
/* These are not inline because of header tangles. */
#ifdef CONFIG_CPUMASK_OFFSTACK
/**
- * alloc_cpumask_var_node - allocate a struct cpumask on a given node
+ * __alloc_cpumask_var_node - allocate a struct cpumask on a given node
* @mask: pointer to cpumask_var_t where the cpumask is returned
* @flags: GFP_ flags
*
@@ -57,8 +57,12 @@ int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
* usually smart enough to know that mask can never be NULL if
* CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case
* too.
+ *
+ * ( Also note that the freshly allocated mask will not be zero
+ * initialized - in contrast to !CONFIG_CPUMASK_OFFSTACK kernels
+ * which typically pass in masks that are already initialized. )
*/
-bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
+bool __alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
{
*mask = kmalloc_node(cpumask_size(), flags, node);

@@ -71,11 +75,11 @@ bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)

return *mask != NULL;
}
-EXPORT_SYMBOL(alloc_cpumask_var_node);
+EXPORT_SYMBOL(__alloc_cpumask_var_node);

bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
{
- return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
+ return __alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
}
EXPORT_SYMBOL(zalloc_cpumask_var_node);

@@ -88,11 +92,11 @@ EXPORT_SYMBOL(zalloc_cpumask_var_node);
* a nop returning a constant 1 (in <linux/cpumask.h>).
* The cpumask is initialized to all zeroes.
*
- * See alloc_cpumask_var_node().
+ * See __alloc_cpumask_var_node().
*/
bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
{
- return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, NUMA_NO_NODE);
+ return __alloc_cpumask_var_node(mask, flags | __GFP_ZERO, NUMA_NO_NODE);
}
EXPORT_SYMBOL(zalloc_cpumask_var);

--
2.5.0

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