/*
* linux/mm/allocpercpu.c
*
- * Separated from slab.c August 11, 2006 Christoph Lameter <clameter@sgi.com>
+ * Separated from slab.c August 11, 2006 Christoph Lameter
*/
#include <linux/mm.h>
#include <linux/module.h>
+#ifndef cache_line_size
+#define cache_line_size() L1_CACHE_BYTES
+#endif
+
/**
* percpu_depopulate - depopulate per-cpu data for given cpu
* @__pdata: per-cpu data to depopulate
void percpu_depopulate(void *__pdata, int cpu)
{
struct percpu_data *pdata = __percpu_disguise(__pdata);
- if (pdata->ptrs[cpu]) {
- kfree(pdata->ptrs[cpu]);
- pdata->ptrs[cpu] = NULL;
- }
+
+ kfree(pdata->ptrs[cpu]);
+ pdata->ptrs[cpu] = NULL;
}
EXPORT_SYMBOL_GPL(percpu_depopulate);
struct percpu_data *pdata = __percpu_disguise(__pdata);
int node = cpu_to_node(cpu);
+ /*
+ * We should make sure each CPU gets private memory.
+ */
+ size = roundup(size, cache_line_size());
+
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
+ if (node_online(node))
+ pdata->ptrs[cpu] = kmalloc_node(size, gfp|__GFP_ZERO, node);
+ else
pdata->ptrs[cpu] = kzalloc(size, gfp);
return pdata->ptrs[cpu];
}
int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
cpumask_t *mask)
{
- cpumask_t populated = CPU_MASK_NONE;
+ cpumask_t populated;
int cpu;
+ cpus_clear(populated);
for_each_cpu_mask(cpu, *mask)
if (unlikely(!percpu_populate(__pdata, size, gfp, cpu))) {
__percpu_depopulate_mask(__pdata, &populated);
*/
void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask)
{
- void *pdata = kzalloc(sizeof(struct percpu_data), gfp);
+ /*
+ * We allocate whole cache lines to avoid false sharing
+ */
+ size_t sz = roundup(nr_cpu_ids * sizeof(void *), cache_line_size());
+ void *pdata = kzalloc(sz, gfp);
void *__pdata = __percpu_disguise(pdata);
if (unlikely(!pdata))
*/
void percpu_free(void *__pdata)
{
+ if (unlikely(!__pdata))
+ return;
__percpu_depopulate_mask(__pdata, &cpu_possible_map);
kfree(__percpu_disguise(__pdata));
}