Separate 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
different allocators that can be used independently from the
slab. This also simplifies SLOB.
Signed-off-by: Christoph Lameter <[email protected]>
Index: linux-2.6.18-rc4/mm/allocpercpu.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.18-rc4/mm/allocpercpu.c 2006-08-13 23:26:17.588539549 -0700
@@ -0,0 +1,76 @@
+/*
+ * linux/mm/allocpercpu.c
+ *
+ * Separated out from slab.c August 11, 2006 Christoph Lameter <[email protected]>
+ */
+#include <linux/mm.h>
+#include <linux/module.h>
+
+/**
+ * __alloc_percpu - allocate one copy of the object for every present
+ * cpu in the system, zeroing them.
+ * Objects should be dereferenced using the per_cpu_ptr macro only.
+ *
+ * @size: how many bytes of memory are required.
+ */
+void *__alloc_percpu(size_t size)
+{
+ int i;
+ struct percpu_data *pdata = kmalloc(sizeof(*pdata), GFP_KERNEL);
+
+ if (!pdata)
+ return NULL;
+
+ /*
+ * Cannot use for_each_online_cpu since a cpu may come online
+ * and we have no way of figuring out how to fix the array
+ * that we have allocated then....
+ */
+ for_each_possible_cpu(i) {
+ int node = cpu_to_node(i);
+
+ if (node_online(node))
+ pdata->ptrs[i] = kmalloc_node(size, GFP_KERNEL, node);
+ else
+ pdata->ptrs[i] = kmalloc(size, GFP_KERNEL);
+
+ if (!pdata->ptrs[i])
+ goto unwind_oom;
+ memset(pdata->ptrs[i], 0, size);
+ }
+
+ /* Catch derefs w/o wrappers */
+ return (void *)(~(unsigned long)pdata);
+
+unwind_oom:
+ while (--i >= 0) {
+ if (!cpu_possible(i))
+ continue;
+ kfree(pdata->ptrs[i]);
+ }
+ kfree(pdata);
+ return NULL;
+}
+EXPORT_SYMBOL(__alloc_percpu);
+
+/**
+ * free_percpu - free previously allocated percpu memory
+ * @objp: pointer returned by alloc_percpu.
+ *
+ * Don't free memory not originally allocated by alloc_percpu()
+ * The complemented objp is to check for that.
+ */
+void free_percpu(const void *objp)
+{
+ int i;
+ struct percpu_data *p = (struct percpu_data *)(~(unsigned long)objp);
+
+ /*
+ * We allocate for all cpus so we cannot use for online cpu here.
+ */
+ for_each_possible_cpu(i)
+ kfree(p->ptrs[i]);
+ kfree(p);
+}
+EXPORT_SYMBOL(free_percpu);
+
Index: linux-2.6.18-rc4/mm/Makefile
===================================================================
--- linux-2.6.18-rc4.orig/mm/Makefile 2006-08-06 11:20:11.000000000 -0700
+++ linux-2.6.18-rc4/mm/Makefile 2006-08-13 23:26:17.597328068 -0700
@@ -13,6 +13,7 @@ obj-y := bootmem.o filemap.o mempool.o
prio_tree.o util.o mmzone.o vmstat.o $(mmu-y)
obj-$(CONFIG_SWAP) += page_io.o swap_state.o swapfile.o thrash.o
+obj-$(CONFIG_SMP) += allocpercpu.o
obj-$(CONFIG_HUGETLBFS) += hugetlb.o
obj-$(CONFIG_NUMA) += mempolicy.o
obj-$(CONFIG_SPARSEMEM) += sparse.o
Index: linux-2.6.18-rc4/mm/slab.c
===================================================================
--- linux-2.6.18-rc4.orig/mm/slab.c 2006-08-13 23:26:17.521160905 -0700
+++ linux-2.6.18-rc4/mm/slab.c 2006-08-13 23:26:17.600257574 -0700
@@ -3390,55 +3390,6 @@ void *__kmalloc_track_caller(size_t size
EXPORT_SYMBOL(__kmalloc_track_caller);
#endif
-#ifdef CONFIG_SMP
-/**
- * __alloc_percpu - allocate one copy of the object for every present
- * cpu in the system, zeroing them.
- * Objects should be dereferenced using the per_cpu_ptr macro only.
- *
- * @size: how many bytes of memory are required.
- */
-void *__alloc_percpu(size_t size)
-{
- int i;
- struct percpu_data *pdata = kmalloc(sizeof(*pdata), GFP_KERNEL);
-
- if (!pdata)
- return NULL;
-
- /*
- * Cannot use for_each_online_cpu since a cpu may come online
- * and we have no way of figuring out how to fix the array
- * that we have allocated then....
- */
- for_each_possible_cpu(i) {
- int node = cpu_to_node(i);
-
- if (node_online(node))
- pdata->ptrs[i] = kmalloc_node(size, GFP_KERNEL, node);
- else
- pdata->ptrs[i] = kmalloc(size, GFP_KERNEL);
-
- if (!pdata->ptrs[i])
- goto unwind_oom;
- memset(pdata->ptrs[i], 0, size);
- }
-
- /* Catch derefs w/o wrappers */
- return (void *)(~(unsigned long)pdata);
-
-unwind_oom:
- while (--i >= 0) {
- if (!cpu_possible(i))
- continue;
- kfree(pdata->ptrs[i]);
- }
- kfree(pdata);
- return NULL;
-}
-EXPORT_SYMBOL(__alloc_percpu);
-#endif
-
/**
* kmem_cache_free - Deallocate an object
* @cachep: The cache the allocation was from.
@@ -3484,29 +3435,6 @@ void kfree(const void *objp)
}
EXPORT_SYMBOL(kfree);
-#ifdef CONFIG_SMP
-/**
- * free_percpu - free previously allocated percpu memory
- * @objp: pointer returned by alloc_percpu.
- *
- * Don't free memory not originally allocated by alloc_percpu()
- * The complemented objp is to check for that.
- */
-void free_percpu(const void *objp)
-{
- int i;
- struct percpu_data *p = (struct percpu_data *)(~(unsigned long)objp);
-
- /*
- * We allocate for all cpus so we cannot use for online cpu here.
- */
- for_each_possible_cpu(i)
- kfree(p->ptrs[i]);
- kfree(p);
-}
-EXPORT_SYMBOL(free_percpu);
-#endif
-
unsigned int kmem_cache_size(struct kmem_cache *cachep)
{
return obj_size(cachep);
Index: linux-2.6.18-rc4/mm/slob.c
===================================================================
--- linux-2.6.18-rc4.orig/mm/slob.c 2006-08-06 11:20:11.000000000 -0700
+++ linux-2.6.18-rc4/mm/slob.c 2006-08-13 23:26:17.611975599 -0700
@@ -343,48 +343,3 @@ void kmem_cache_init(void)
atomic_t slab_reclaim_pages = ATOMIC_INIT(0);
EXPORT_SYMBOL(slab_reclaim_pages);
-#ifdef CONFIG_SMP
-
-void *__alloc_percpu(size_t size)
-{
- int i;
- struct percpu_data *pdata = kmalloc(sizeof (*pdata), GFP_KERNEL);
-
- if (!pdata)
- return NULL;
-
- for_each_possible_cpu(i) {
- pdata->ptrs[i] = kmalloc(size, GFP_KERNEL);
- if (!pdata->ptrs[i])
- goto unwind_oom;
- memset(pdata->ptrs[i], 0, size);
- }
-
- /* Catch derefs w/o wrappers */
- return (void *) (~(unsigned long) pdata);
-
-unwind_oom:
- while (--i >= 0) {
- if (!cpu_possible(i))
- continue;
- kfree(pdata->ptrs[i]);
- }
- kfree(pdata);
- return NULL;
-}
-EXPORT_SYMBOL(__alloc_percpu);
-
-void
-free_percpu(const void *objp)
-{
- int i;
- struct percpu_data *p = (struct percpu_data *) (~(unsigned long) objp);
-
- for_each_possible_cpu(i)
- kfree(p->ptrs[i]);
-
- kfree(p);
-}
-EXPORT_SYMBOL(free_percpu);
-
-#endif
-
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