On Tue, 2 Jan 2024 19:46:29 +0100 Uladzislau Rezki <urezki@xxxxxxxxx> > +static void > +decay_va_pool_node(struct vmap_node *vn, bool full_decay) > +{ > + struct vmap_area *va, *nva; > + struct list_head decay_list; > + struct rb_root decay_root; > + unsigned long n_decay; > + int i; > + > + decay_root = RB_ROOT; > + INIT_LIST_HEAD(&decay_list); > + > + for (i = 0; i < MAX_VA_SIZE_PAGES; i++) { > + struct list_head tmp_list; > + > + if (list_empty(&vn->pool[i].head)) > + continue; > + > + INIT_LIST_HEAD(&tmp_list); > + > + /* Detach the pool, so no-one can access it. */ > + spin_lock(&vn->pool_lock); > + list_replace_init(&vn->pool[i].head, &tmp_list); > + spin_unlock(&vn->pool_lock); > + > + if (full_decay) > + WRITE_ONCE(vn->pool[i].len, 0); > + > + /* Decay a pool by ~25% out of left objects. */ > + n_decay = vn->pool[i].len >> 2; > + > + list_for_each_entry_safe(va, nva, &tmp_list, list) { > + list_del_init(&va->list); > + merge_or_add_vmap_area(va, &decay_root, &decay_list); > + > + if (!full_decay) { > + WRITE_ONCE(vn->pool[i].len, vn->pool[i].len - 1); > + > + if (!--n_decay) > + break; > + } > + } > + > + /* Attach the pool back if it has been partly decayed. */ > + if (!full_decay && !list_empty(&tmp_list)) { > + spin_lock(&vn->pool_lock); > + list_replace_init(&tmp_list, &vn->pool[i].head); > + spin_unlock(&vn->pool_lock); > + } Failure of working out why list_splice() was not used here in case of non-empty vn->pool[i].head, after staring ten minutes. > + } > + > + reclaim_list_global(&decay_list); > +}