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linux-next/mm/allocpercpu.c
Alan Stern a120586873 [PATCH] Allow NULL pointers in percpu_free
The patch (as824b) makes percpu_free() ignore NULL arguments, as one would
expect for a deallocation routine.  (Note that free_percpu is #defined as
percpu_free in include/linux/percpu.h.) A few callers are updated to remove
now-unneeded tests for NULL.  A few other callers already seem to assume
that passing a NULL pointer to percpu_free() is okay!

The patch also removes an unnecessary NULL check in percpu_depopulate().

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:22 -08:00

131 lines
3.7 KiB
C

/*
* linux/mm/allocpercpu.c
*
* Separated from slab.c August 11, 2006 Christoph Lameter <clameter@sgi.com>
*/
#include <linux/mm.h>
#include <linux/module.h>
/**
* percpu_depopulate - depopulate per-cpu data for given cpu
* @__pdata: per-cpu data to depopulate
* @cpu: depopulate per-cpu data for this cpu
*
* Depopulating per-cpu data for a cpu going offline would be a typical
* use case. You need to register a cpu hotplug handler for that purpose.
*/
void percpu_depopulate(void *__pdata, int cpu)
{
struct percpu_data *pdata = __percpu_disguise(__pdata);
kfree(pdata->ptrs[cpu]);
pdata->ptrs[cpu] = NULL;
}
EXPORT_SYMBOL_GPL(percpu_depopulate);
/**
* percpu_depopulate_mask - depopulate per-cpu data for some cpu's
* @__pdata: per-cpu data to depopulate
* @mask: depopulate per-cpu data for cpu's selected through mask bits
*/
void __percpu_depopulate_mask(void *__pdata, cpumask_t *mask)
{
int cpu;
for_each_cpu_mask(cpu, *mask)
percpu_depopulate(__pdata, cpu);
}
EXPORT_SYMBOL_GPL(__percpu_depopulate_mask);
/**
* percpu_populate - populate per-cpu data for given cpu
* @__pdata: per-cpu data to populate further
* @size: size of per-cpu object
* @gfp: may sleep or not etc.
* @cpu: populate per-data for this cpu
*
* Populating per-cpu data for a cpu coming online would be a typical
* use case. You need to register a cpu hotplug handler for that purpose.
* Per-cpu object is populated with zeroed buffer.
*/
void *percpu_populate(void *__pdata, size_t size, gfp_t gfp, int cpu)
{
struct percpu_data *pdata = __percpu_disguise(__pdata);
int node = cpu_to_node(cpu);
BUG_ON(pdata->ptrs[cpu]);
if (node_online(node)) {
/* FIXME: kzalloc_node(size, gfp, node) */
pdata->ptrs[cpu] = kmalloc_node(size, gfp, node);
if (pdata->ptrs[cpu])
memset(pdata->ptrs[cpu], 0, size);
} else
pdata->ptrs[cpu] = kzalloc(size, gfp);
return pdata->ptrs[cpu];
}
EXPORT_SYMBOL_GPL(percpu_populate);
/**
* percpu_populate_mask - populate per-cpu data for more cpu's
* @__pdata: per-cpu data to populate further
* @size: size of per-cpu object
* @gfp: may sleep or not etc.
* @mask: populate per-cpu data for cpu's selected through mask bits
*
* Per-cpu objects are populated with zeroed buffers.
*/
int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
cpumask_t *mask)
{
cpumask_t populated = CPU_MASK_NONE;
int cpu;
for_each_cpu_mask(cpu, *mask)
if (unlikely(!percpu_populate(__pdata, size, gfp, cpu))) {
__percpu_depopulate_mask(__pdata, &populated);
return -ENOMEM;
} else
cpu_set(cpu, populated);
return 0;
}
EXPORT_SYMBOL_GPL(__percpu_populate_mask);
/**
* percpu_alloc_mask - initial setup of per-cpu data
* @size: size of per-cpu object
* @gfp: may sleep or not etc.
* @mask: populate per-data for cpu's selected through mask bits
*
* Populating per-cpu data for all online cpu's would be a typical use case,
* which is simplified by the percpu_alloc() wrapper.
* Per-cpu objects are populated with zeroed buffers.
*/
void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask)
{
void *pdata = kzalloc(sizeof(struct percpu_data), gfp);
void *__pdata = __percpu_disguise(pdata);
if (unlikely(!pdata))
return NULL;
if (likely(!__percpu_populate_mask(__pdata, size, gfp, mask)))
return __pdata;
kfree(pdata);
return NULL;
}
EXPORT_SYMBOL_GPL(__percpu_alloc_mask);
/**
* percpu_free - final cleanup of per-cpu data
* @__pdata: object to clean up
*
* We simply clean up any per-cpu object left. No need for the client to
* track and specify through a bis mask which per-cpu objects are to free.
*/
void percpu_free(void *__pdata)
{
if (unlikely(!__pdata))
return;
__percpu_depopulate_mask(__pdata, &cpu_possible_map);
kfree(__percpu_disguise(__pdata));
}
EXPORT_SYMBOL_GPL(percpu_free);