[PATCH 6/8] percpu: add an indirection ptr for chunk page map access

Tejun Heo
2009-03-06T06:50:36Z

Impact: allow sharing page map, no functional difference yet

Make chunk->page access indirect by adding a pointer and renaming the
actual array to page_ar. This will be used by future changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
---
mm/percpu.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/mm/percpu.c b/mm/percpu.c
index a84cf99..5b47d9f 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -80,7 +80,8 @@ struct pcpu_chunk {
int map_alloc; /* # of map entries allocated */
int *map; /* allocation map */
bool immutable; /* no [de]population allowed */
- struct page *page[]; /* #cpus * UNIT_PAGES */
+ struct page **page; /* points to page array */
+ struct page *page_ar[]; /* #cpus * UNIT_PAGES */
};

static int pcpu_unit_pages __read_mostly;
@@ -696,6 +697,7 @@ static struct pcpu_chunk *alloc_pcpu_chunk(void)
PCPU_DFL_MAP_ALLOC * sizeof(chunk->map[0]));
chunk->map_alloc = PCPU_DFL_MAP_ALLOC;
chunk->map[chunk->map_used++] = pcpu_unit_size;
+ chunk->page = chunk->page_ar;

chunk->vm = get_vm_area(pcpu_chunk_size, GFP_KERNEL);
if (!chunk->vm) {
@@ -918,6 +920,7 @@ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,
schunk->vm = &first_vm;
schunk->map = smap;
schunk->map_alloc = ARRAY_SIZE(smap);
+ schunk->page = schunk->page_ar;
schunk->free_size = dyn_size;
schunk->contig_hint = schunk->free_size;

--
1.6.0.2