From d00bcc98d7ec2c87391c9d9e1cca519ef64d33ef Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Mon, 25 Sep 2006 23:31:50 -0700 Subject: [PATCH] Extract the allocpercpu functions from the slab allocator The allocpercpu functions __alloc_percpu and __free_percpu() are heavily using the slab allocator. However, they are conceptually slab. This also simplifies SLOB (at this point slob may be broken in mm. This should fix it). Signed-off-by: Christoph Lameter Cc: Matt Mackall Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/allocpercpu.c | 129 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 129 insertions(+) create mode 100644 mm/allocpercpu.c (limited to 'mm/allocpercpu.c') diff --git a/mm/allocpercpu.c b/mm/allocpercpu.c new file mode 100644 index 000000000000..eaa9abeea536 --- /dev/null +++ b/mm/allocpercpu.c @@ -0,0 +1,129 @@ +/* + * linux/mm/allocpercpu.c + * + * Separated from slab.c August 11, 2006 Christoph Lameter + */ +#include +#include + +/** + * 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); + if (pdata->ptrs[cpu]) { + 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) +{ + __percpu_depopulate_mask(__pdata, &cpu_possible_map); + kfree(__percpu_disguise(__pdata)); +} +EXPORT_SYMBOL_GPL(percpu_free); -- cgit v1.2.3-58-ga151