/*
* 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>
+#include <linux/bootmem.h>
+#include <asm/sections.h>
+
+#ifndef cache_line_size
+#define cache_line_size() L1_CACHE_BYTES
+#endif
/**
* percpu_depopulate - depopulate per-cpu data for given 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)
+static 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)
+static void __percpu_depopulate_mask(void *__pdata, const cpumask_t *mask)
{
int cpu;
- for_each_cpu_mask(cpu, *mask)
+ for_each_cpu_mask_nr(cpu, *mask)
percpu_depopulate(__pdata, cpu);
}
-EXPORT_SYMBOL_GPL(__percpu_depopulate_mask);
+
+#define percpu_depopulate_mask(__pdata, mask) \
+ __percpu_depopulate_mask((__pdata), &(mask))
/**
* percpu_populate - populate per-cpu data for given cpu
* 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)
+static 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);
+ /*
+ * We should make sure each CPU gets private memory.
+ */
+ size = roundup(size, cache_line_size());
+
BUG_ON(pdata->ptrs[cpu]);
if (node_online(node))
pdata->ptrs[cpu] = kmalloc_node(size, gfp|__GFP_ZERO, node);
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
*
* Per-cpu objects are populated with zeroed buffers.
*/
-int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
- cpumask_t *mask)
+static 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;
- for_each_cpu_mask(cpu, *mask)
+ cpus_clear(populated);
+ for_each_cpu_mask_nr(cpu, *mask)
if (unlikely(!percpu_populate(__pdata, size, gfp, cpu))) {
__percpu_depopulate_mask(__pdata, &populated);
return -ENOMEM;
cpu_set(cpu, populated);
return 0;
}
-EXPORT_SYMBOL_GPL(__percpu_populate_mask);
+
+#define percpu_populate_mask(__pdata, size, gfp, mask) \
+ __percpu_populate_mask((__pdata), (size), (gfp), &(mask))
/**
- * percpu_alloc_mask - initial setup of per-cpu data
+ * alloc_percpu - 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
+ * @align: alignment
*
- * 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.
+ * Allocate dynamic percpu area. Percpu objects are populated with
+ * zeroed buffers.
*/
-void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask)
+void *__alloc_percpu(size_t size, size_t align)
{
- void *pdata = kzalloc(nr_cpu_ids * sizeof(void *), 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_KERNEL);
void *__pdata = __percpu_disguise(pdata);
+ /*
+ * Can't easily make larger alignment work with kmalloc. WARN
+ * on it. Larger alignment should only be used for module
+ * percpu sections on SMP for which this path isn't used.
+ */
+ WARN_ON_ONCE(align > SMP_CACHE_BYTES);
+
if (unlikely(!pdata))
return NULL;
- if (likely(!__percpu_populate_mask(__pdata, size, gfp, mask)))
+ if (likely(!__percpu_populate_mask(__pdata, size, GFP_KERNEL,
+ &cpu_possible_map)))
return __pdata;
kfree(pdata);
return NULL;
}
-EXPORT_SYMBOL_GPL(__percpu_alloc_mask);
+EXPORT_SYMBOL_GPL(__alloc_percpu);
/**
- * percpu_free - final cleanup of per-cpu data
+ * free_percpu - 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)
+void free_percpu(void *__pdata)
{
if (unlikely(!__pdata))
return;
- __percpu_depopulate_mask(__pdata, &cpu_possible_map);
+ __percpu_depopulate_mask(__pdata, cpu_possible_mask);
kfree(__percpu_disguise(__pdata));
}
-EXPORT_SYMBOL_GPL(percpu_free);
+EXPORT_SYMBOL_GPL(free_percpu);
+
+/*
+ * Generic percpu area setup.
+ */
+#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
+unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
+
+EXPORT_SYMBOL(__per_cpu_offset);
+
+void __init setup_per_cpu_areas(void)
+{
+ unsigned long size, i;
+ char *ptr;
+ unsigned long nr_possible_cpus = num_possible_cpus();
+
+ /* Copy section for each CPU (we discard the original) */
+ size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
+ ptr = alloc_bootmem_pages(size * nr_possible_cpus);
+
+ for_each_possible_cpu(i) {
+ __per_cpu_offset[i] = ptr - __per_cpu_start;
+ memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
+ ptr += size;
+ }
+}
+#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
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