[PATCH 2/5] percpu: reorganize chunk creation and destruction

From: Tejun Heo
Date: Thu Apr 08 2010 - 00:13:02 EST


Reorganize alloc/free_pcpu_chunk() such that chunk struct alloc/free
live in pcpu_alloc/free_chunk() and the rest in
pcpu_create/destroy_chunk().

This patch doesn't cause any functional change. This is to allow
alternate chunk management implementation for percpu nommu support.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Cc: Graff Yang <graff.yang@xxxxxxxxx>
Cc: Sonic Zhang <sonic.adi@xxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
---
mm/percpu.c | 65 +++++++++++++++++++++++++++++++++++++---------------------
1 files changed, 41 insertions(+), 24 deletions(-)

diff --git a/mm/percpu.c b/mm/percpu.c
index 1aeb081..c30ca03 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -636,6 +636,33 @@ static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme)
pcpu_chunk_relocate(chunk, oslot);
}

+static struct pcpu_chunk *pcpu_alloc_chunk(void)
+{
+ struct pcpu_chunk *chunk;
+
+ chunk = kzalloc(pcpu_chunk_struct_size, GFP_KERNEL);
+ if (!chunk)
+ return NULL;
+
+ chunk->map = pcpu_mem_alloc(PCPU_DFL_MAP_ALLOC * sizeof(chunk->map[0]));
+ chunk->map_alloc = PCPU_DFL_MAP_ALLOC;
+ chunk->map[chunk->map_used++] = pcpu_unit_size;
+
+ INIT_LIST_HEAD(&chunk->list);
+ chunk->free_size = pcpu_unit_size;
+ chunk->contig_hint = pcpu_unit_size;
+
+ return chunk;
+}
+
+static void pcpu_free_chunk(struct pcpu_chunk *chunk)
+{
+ if (!chunk)
+ return;
+ pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0]));
+ kfree(chunk);
+}
+
/**
* pcpu_get_pages_and_bitmap - get temp pages array and bitmap
* @chunk: chunk of interest
@@ -1028,41 +1055,31 @@ err_free:
return rc;
}

-static void free_pcpu_chunk(struct pcpu_chunk *chunk)
+static void pcpu_destroy_chunk(struct pcpu_chunk *chunk)
{
- if (!chunk)
- return;
- if (chunk->vms)
+ if (chunk && chunk->vms)
pcpu_free_vm_areas(chunk->vms, pcpu_nr_groups);
- pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0]));
- kfree(chunk);
+ pcpu_free_chunk(chunk);
}

-static struct pcpu_chunk *alloc_pcpu_chunk(void)
+static struct pcpu_chunk *pcpu_create_chunk(void)
{
struct pcpu_chunk *chunk;
+ struct vm_struct **vms;

- chunk = kzalloc(pcpu_chunk_struct_size, GFP_KERNEL);
+ chunk = pcpu_alloc_chunk();
if (!chunk)
return NULL;

- chunk->map = pcpu_mem_alloc(PCPU_DFL_MAP_ALLOC * sizeof(chunk->map[0]));
- chunk->map_alloc = PCPU_DFL_MAP_ALLOC;
- chunk->map[chunk->map_used++] = pcpu_unit_size;
-
- chunk->vms = pcpu_get_vm_areas(pcpu_group_offsets, pcpu_group_sizes,
- pcpu_nr_groups, pcpu_atom_size,
- GFP_KERNEL);
- if (!chunk->vms) {
- free_pcpu_chunk(chunk);
+ vms = pcpu_get_vm_areas(pcpu_group_offsets, pcpu_group_sizes,
+ pcpu_nr_groups, pcpu_atom_size, GFP_KERNEL);
+ if (!vms) {
+ pcpu_free_chunk(chunk);
return NULL;
}

- INIT_LIST_HEAD(&chunk->list);
- chunk->free_size = pcpu_unit_size;
- chunk->contig_hint = pcpu_unit_size;
- chunk->base_addr = chunk->vms[0]->addr - pcpu_group_offsets[0];
-
+ chunk->vms = vms;
+ chunk->base_addr = vms[0]->addr - pcpu_group_offsets[0];
return chunk;
}

@@ -1155,7 +1172,7 @@ restart:
/* hmmm... no space left, create a new chunk */
spin_unlock_irqrestore(&pcpu_lock, flags);

- chunk = alloc_pcpu_chunk();
+ chunk = pcpu_create_chunk();
if (!chunk) {
err = "failed to allocate new chunk";
goto fail_unlock_mutex;
@@ -1267,7 +1284,7 @@ static void pcpu_reclaim(struct work_struct *work)

list_for_each_entry_safe(chunk, next, &todo, list) {
pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size);
- free_pcpu_chunk(chunk);
+ pcpu_destroy_chunk(chunk);
}

mutex_unlock(&pcpu_alloc_mutex);
--
1.6.4.2

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