5.4-stable review patch. If anyone has any objections, please let me know.
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From: Zhen Lei thunder.leizhen@huawei.com
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@huawei.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20240904133944.2124-3-thunder.leizhen@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- lib/debugobjects.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -143,13 +143,14 @@ 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);