1.8.x afs_inode_cache more slab usage

Hello all,
   It seems that OpenAFS 1.8.x uses more slab (or doesn't free it as 
quickly) than 1.6.20 .

   The machine in question uses AFS heavily. it is used to backup our 
AFS area. It scans through files constantly and in more than directory 
and in two domains at a time.
   I recently upgraded from Debian Stretch running openafs 1.6.20 to 
Debian Buster 1.8.2.  After encountering the problem I also tried Debian 
Bullseye (testing) with openafs 1.8.6.  Same symptoms.
   On a 6GB (virtual) machine it used enough to start swapping and kill 
the machine.
   The last output of 'slabtop' says:
OBJS ACTIVE USE OBJSIZE SLABS OBJ/SLAB CACHE SIZE NAME
5235885 5235885 100% 1.06K 539811 15 8636976K afs_inode_cache

   Any way to change this behavior?

Thanks!
Cahd.