mm/zsmalloc: avoid calculate max objects of zspage twice
Currently, if a class can not be merged, the max objects of zspage in
that class may be calculated twice.
This patch calculate max objects of zspage at the begin, and pass the
value to can_merge() to decide whether the class can be merged.
Also this patch remove function get_maxobj_per_zspage(), as there is no
other place to call this function.
Link: http://lkml.kernel.org/r/1467882338-4300-4-git-send-email-opensource.ganesh@gmail.com
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.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 72e0b29..1ce7745 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -467,11 +467,6 @@
MODULE_ALIAS("zpool-zsmalloc");
#endif /* CONFIG_ZPOOL */
-static unsigned int get_maxobj_per_zspage(int size, int pages_per_zspage)
-{
- return pages_per_zspage * PAGE_SIZE / size;
-}
-
/* per-cpu VM mapping areas for zspage accesses that cross page boundaries */
static DEFINE_PER_CPU(struct mapping_area, zs_map_area);
@@ -1359,16 +1354,14 @@
zs_size_classes = nr;
}
-static bool can_merge(struct size_class *prev, int size, int pages_per_zspage)
+static bool can_merge(struct size_class *prev, int pages_per_zspage,
+ int objs_per_zspage)
{
- if (prev->pages_per_zspage != pages_per_zspage)
- return false;
+ if (prev->pages_per_zspage == pages_per_zspage &&
+ prev->objs_per_zspage == objs_per_zspage)
+ return true;
- if (prev->objs_per_zspage
- != get_maxobj_per_zspage(size, pages_per_zspage))
- return false;
-
- return true;
+ return false;
}
static bool zspage_full(struct size_class *class, struct zspage *zspage)
@@ -2438,6 +2431,7 @@
for (i = zs_size_classes - 1; i >= 0; i--) {
int size;
int pages_per_zspage;
+ int objs_per_zspage;
struct size_class *class;
int fullness = 0;
@@ -2445,6 +2439,7 @@
if (size > ZS_MAX_ALLOC_SIZE)
size = ZS_MAX_ALLOC_SIZE;
pages_per_zspage = get_pages_per_zspage(size);
+ objs_per_zspage = pages_per_zspage * PAGE_SIZE / size;
/*
* size_class is used for normal zsmalloc operation such
@@ -2456,7 +2451,7 @@
* previous size_class if possible.
*/
if (prev_class) {
- if (can_merge(prev_class, size, pages_per_zspage)) {
+ if (can_merge(prev_class, pages_per_zspage, objs_per_zspage)) {
pool->size_class[i] = prev_class;
continue;
}
@@ -2469,8 +2464,7 @@
class->size = size;
class->index = i;
class->pages_per_zspage = pages_per_zspage;
- class->objs_per_zspage = get_maxobj_per_zspage(class->size,
- class->pages_per_zspage);
+ class->objs_per_zspage = objs_per_zspage;
spin_lock_init(&class->lock);
pool->size_class[i] = class;
for (fullness = ZS_EMPTY; fullness < NR_ZS_FULLNESS;