[PATCH 2/6] percpu: drop @unit_size from embed first chunk allocator

Tejun Heo
2009-06-17T04:05:49Z

The only extra feature @unit_size provides is making dead space at the
end of the first chunk which doesn't have any valid usecase. Drop the
parameter. This will increase consistency with generalized 4k
allocator.

[ Impact: drop unused code path ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
---
arch/x86/kernel/setup_percpu.c | 2 +-
include/linux/percpu.h | 2 +-
mm/percpu.c | 16 +++++-----------
3 files changed, 7 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 29a3eef..1472820 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -342,7 +342,7 @@ static ssize_t __init setup_pcpu_embed(size_t static_size, bool chosen)
return -EINVAL;

return pcpu_embed_first_chunk(static_size, PERCPU_FIRST_CHUNK_RESERVE,
- reserve - PERCPU_FIRST_CHUNK_RESERVE, -1);
+ reserve - PERCPU_FIRST_CHUNK_RESERVE);
}

/*
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index e500034..83bff05 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -69,7 +69,7 @@ extern size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,

extern ssize_t __init pcpu_embed_first_chunk(
size_t static_size, size_t reserved_size,
- ssize_t dyn_size, ssize_t unit_size);
+ ssize_t dyn_size);

/*
* Use this to get to a cpu's version of the per-cpu object
diff --git a/mm/percpu.c b/mm/percpu.c
index 19dd83b..fe34b6b 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1207,7 +1207,6 @@ static struct page * __init pcpue_get_page(unsigned int cpu, int pageno)
* @static_size: the size of static percpu area in bytes
* @reserved_size: the size of reserved percpu area in bytes
* @dyn_size: free size for dynamic allocation in bytes, -1 for auto
- * @unit_size: unit size in bytes, must be multiple of PAGE_SIZE, -1 for auto
*
* This is a helper to ease setting up embedded first percpu chunk and
* can be called where pcpu_setup_first_chunk() is expected.
@@ -1219,9 +1218,9 @@ static struct page * __init pcpue_get_page(unsigned int cpu, int pageno)
* page size.
*
* When @dyn_size is positive, dynamic area might be larger than
- * specified to fill page alignment. Also, when @dyn_size is auto,
- * @dyn_size does not fill the whole first chunk but only what's
- * necessary for page alignment after static and reserved areas.
+ * specified to fill page alignment. When @dyn_size is auto,
+ * @dyn_size is just big enough to fill page alignment after static
+ * and reserved areas.
*
* If the needed size is smaller than the minimum or specified unit
* size, the leftover is returned to the bootmem allocator.
@@ -1231,7 +1230,7 @@ static struct page * __init pcpue_get_page(unsigned int cpu, int pageno)
* percpu access on success, -errno on failure.
*/
ssize_t __init pcpu_embed_first_chunk(size_t static_size, size_t reserved_size,
- ssize_t dyn_size, ssize_t unit_size)
+ ssize_t dyn_size)
{
size_t chunk_size;
unsigned int cpu;
@@ -1242,12 +1241,7 @@ ssize_t __init pcpu_embed_first_chunk(size_t static_size, size_t reserved_size,
if (dyn_size != 0)
dyn_size = pcpue_size - static_size - reserved_size;

- if (unit_size >= 0) {
- BUG_ON(unit_size < pcpue_size);
- pcpue_unit_size = unit_size;
- } else
- pcpue_unit_size = max_t(size_t, pcpue_size, PCPU_MIN_UNIT_SIZE);
-
+ pcpue_unit_size = max_t(size_t, pcpue_size, PCPU_MIN_UNIT_SIZE);
chunk_size = pcpue_unit_size * num_possible_cpus();

pcpue_ptr = __alloc_bootmem_nopanic(chunk_size, PAGE_SIZE,
--
1.6.0.2