5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
commit 684d28feb8546d1e9597aa363c3bfcf52fe250b7 upstream.
fill_pool() uses 'obj_pool_min_free' to decide whether objects should be
handed back to the kmem cache. But 'obj_pool_min_free' records the lowest
historical value of the number of objects in the object pool and not the
minimum number of objects which should be kept in the pool.
Use 'debug_objects_pool_min_level' instead, which holds the minimum number
which was scaled to the number of CPUs at boot time.
[ tglx: Massage change log ]
Fixes: d26bf5056fc0 ("debugobjects: Reduce number of pool_lock acquisitions in fill_pool()")
Fixes: 36c4ead6f6df ("debugobjects: Add global free list and the counter")
Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/all/20240904133944.2124-3-thunder.leizhen@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
lib/debugobjects.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -144,13 +144,14 @@ static void fill_pool(void)
* READ_ONCE()s pair with the WRITE_ONCE()s in pool_lock critical
* sections.
*/
- while (READ_ONCE(obj_nr_tofree) && (READ_ONCE(obj_pool_free) < obj_pool_min_free)) {
+ while (READ_ONCE(obj_nr_tofree) &&
+ READ_ONCE(obj_pool_free) < debug_objects_pool_min_level) {
raw_spin_lock_irqsave(&pool_lock, flags);
/*
* Recheck with the lock held as the worker thread might have
* won the race and freed the global free list already.
*/
- while (obj_nr_tofree && (obj_pool_free < obj_pool_min_free)) {
+ while (obj_nr_tofree && (obj_pool_free < debug_objects_pool_min_level)) {
obj = hlist_entry(obj_to_free.first, typeof(*obj), node);
hlist_del(&obj->node);
WRITE_ONCE(obj_nr_tofree, obj_nr_tofree - 1);
