After the previous cleanups, we can now move some code from
calc_slab_order() to calculate_order() so it's executed just once, and
do some more cleanups.
- move the min_order and MAX_OBJS_PER_PAGE evaluation to
calc_slab_order().
- change calc_slab_order() parameter min_objects to min_order
Also make MAX_OBJS_PER_PAGE check more robust by considering also
min_objects in addition to slub_min_order. Otherwise this is not a
functional change.
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
---
mm/slub.c | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c
index f04eb029d85a..1c91f72c7239 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4110,17 +4110,12 @@ static unsigned int slub_min_objects;
* the smallest order which will fit the object.
*/
static inline unsigned int calc_slab_order(unsigned int size,
- unsigned int min_objects, unsigned int max_order,
+ unsigned int min_order, unsigned int max_order,
unsigned int fract_leftover)
{
- unsigned int min_order = slub_min_order;
unsigned int order;
- if (order_objects(min_order, size) > MAX_OBJS_PER_PAGE)
- return get_order(size * MAX_OBJS_PER_PAGE) - 1;
-
- for (order = max(min_order, (unsigned int)get_order(min_objects * size));
- order <= max_order; order++) {
+ for (order = min_order; order <= max_order; order++) {
unsigned int slab_size = (unsigned int)PAGE_SIZE << order;
unsigned int rem;
@@ -4139,7 +4134,7 @@ static inline int calculate_order(unsigned int size)
unsigned int order;
unsigned int min_objects;
unsigned int max_objects;
- unsigned int nr_cpus;
+ unsigned int min_order;
min_objects = slub_min_objects;
if (!min_objects) {
@@ -4152,7 +4147,7 @@ static inline int calculate_order(unsigned int size)
* order on systems that appear larger than they are, and too
* low order on systems that appear smaller than they are.
*/
- nr_cpus = num_present_cpus();
+ unsigned int nr_cpus = num_present_cpus();
if (nr_cpus <= 1)
nr_cpus = nr_cpu_ids;
min_objects = 4 * (fls(nr_cpus) + 1);
@@ -4160,6 +4155,10 @@ static inline int calculate_order(unsigned int size)
max_objects = order_objects(slub_max_order, size);
min_objects = min(min_objects, max_objects);
+ min_order = max(slub_min_order, (unsigned int)get_order(min_objects * size));
+ if (order_objects(min_order, size) > MAX_OBJS_PER_PAGE)
+ return get_order(size * MAX_OBJS_PER_PAGE) - 1;
+
/*
* Attempt to find best configuration for a slab. This works by first
* attempting to generate a layout with the best possible configuration and
@@ -4176,7 +4175,7 @@ static inline int calculate_order(unsigned int size)
* long as at least single object fits within slub_max_order.
*/
for (unsigned int fraction = 16; fraction > 1; fraction /= 2) {
- order = calc_slab_order(size, min_objects, slub_max_order,
+ order = calc_slab_order(size, min_order, slub_max_order,
fraction);
if (order <= slub_max_order)
return order;
--
2.42.0
