mm/zsmalloc: avoid duplicate assignment of prev_class
In zs_create_pool(), prev_class is assigned (ZS_SIZE_CLASSES - 1) times.
And the prev_class only references to the previous size_class. So we do
not need unnecessary assignement.
This patch assigns *prev_class* when a new size_class structure is
allocated and uses prev_class to check whether the first class has been
allocated.
[akpm@linux-foundation.org: remove now-unused ZS_SIZE_CLASSES]
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Reviewed-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 61e1809..2021df5 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -155,8 +155,6 @@
* (reason above)
*/
#define ZS_SIZE_CLASS_DELTA (PAGE_SIZE >> 8)
-#define ZS_SIZE_CLASSES ((ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) / \
- ZS_SIZE_CLASS_DELTA + 1)
/*
* We do not maintain any list for completely empty or full pages
@@ -983,6 +981,7 @@
{
int i, ovhd_size;
struct zs_pool *pool;
+ struct size_class *prev_class = NULL;
ovhd_size = roundup(sizeof(*pool), PAGE_SIZE);
pool = kzalloc(ovhd_size, GFP_KERNEL);
@@ -1004,7 +1003,6 @@
int size;
int pages_per_zspage;
struct size_class *class;
- struct size_class *prev_class;
size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA;
if (size > ZS_MAX_ALLOC_SIZE)
@@ -1020,8 +1018,7 @@
* characteristics. So, we makes size_class point to
* previous size_class if possible.
*/
- if (i < ZS_SIZE_CLASSES - 1) {
- prev_class = pool->size_class[i + 1];
+ if (prev_class) {
if (can_merge(prev_class, size, pages_per_zspage)) {
pool->size_class[i] = prev_class;
continue;
@@ -1037,6 +1034,8 @@
class->pages_per_zspage = pages_per_zspage;
spin_lock_init(&class->lock);
pool->size_class[i] = class;
+
+ prev_class = class;
}
pool->flags = flags;