IB/hfi1: Add cache evict LRU list

The original code used a LRU list to evict nodes which were least
recently used.  For correctness the evict code was moved under the
handler->lock, now add back the LRU list.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/hw/hfi1/mmu_rb.c b/drivers/infiniband/hw/hfi1/mmu_rb.c
index a02344a..7ad3089 100644 (file)
--- a/drivers/infiniband/hw/hfi1/mmu_rb.c
+++ b/drivers/infiniband/hw/hfi1/mmu_rb.c
@@ -59,6 +59,7 @@ struct mmu_rb_handler {
        spinlock_t lock;        /* protect the RB tree */
        struct mmu_rb_ops *ops;
        struct mm_struct *mm;
+       struct list_head lru_list;
        struct work_struct del_work;
        struct list_head del_list;
        struct workqueue_struct *wq;
@@ -119,6 +120,7 @@ int hfi1_mmu_rb_register(void *ops_arg, struct mm_struct *mm,
        handlr->mm = mm;
        INIT_WORK(&handlr->del_work, handle_remove);
        INIT_LIST_HEAD(&handlr->del_list);
+       INIT_LIST_HEAD(&handlr->lru_list);
        handlr->wq = wq;
 
        ret = mmu_notifier_register(&handlr->mn, handlr->mm);
@@ -153,7 +155,8 @@ void hfi1_mmu_rb_unregister(struct mmu_rb_handler *handler)
        while ((node = rb_first(&handler->root))) {
                rbnode = rb_entry(node, struct mmu_rb_node, node);
                rb_erase(node, &handler->root);
-               list_add(&rbnode->list, &del_list);
+               /* move from LRU list to delete list */
+               list_move(&rbnode->list, &del_list);
        }
        spin_unlock_irqrestore(&handler->lock, flags);
 
@@ -178,10 +181,13 @@ int hfi1_mmu_rb_insert(struct mmu_rb_handler *handler,
                goto unlock;
        }
        __mmu_int_rb_insert(mnode, &handler->root);
+       list_add(&mnode->list, &handler->lru_list);
 
        ret = handler->ops->insert(handler->ops_arg, mnode);
-       if (ret)
+       if (ret) {
                __mmu_int_rb_remove(mnode, &handler->root);
+               list_del(&mnode->list); /* remove from LRU list */
+       }
 unlock:
        spin_unlock_irqrestore(&handler->lock, flags);
        return ret;
@@ -219,8 +225,10 @@ struct mmu_rb_node *hfi1_mmu_rb_extract(struct mmu_rb_handler *handler,
 
        spin_lock_irqsave(&handler->lock, flags);
        node = __mmu_rb_search(handler, addr, len);
-       if (node)
+       if (node) {
                __mmu_int_rb_remove(node, &handler->root);
+               list_del(&node->list); /* remove from LRU list */
+       }
        spin_unlock_irqrestore(&handler->lock, flags);
 
        return node;
@@ -228,8 +236,7 @@ struct mmu_rb_node *hfi1_mmu_rb_extract(struct mmu_rb_handler *handler,
 
 void hfi1_mmu_rb_evict(struct mmu_rb_handler *handler, void *evict_arg)
 {
-       struct mmu_rb_node *rbnode;
-       struct rb_node *node, *next;
+       struct mmu_rb_node *rbnode, *ptr;
        struct list_head del_list;
        unsigned long flags;
        bool stop = false;
@@ -237,13 +244,13 @@ void hfi1_mmu_rb_evict(struct mmu_rb_handler *handler, void *evict_arg)
        INIT_LIST_HEAD(&del_list);
 
        spin_lock_irqsave(&handler->lock, flags);
-       for (node = rb_first(&handler->root); node; node = next) {
-               next = rb_next(node);
-               rbnode = rb_entry(node, struct mmu_rb_node, node);
+       list_for_each_entry_safe_reverse(rbnode, ptr, &handler->lru_list,
+                                        list) {
                if (handler->ops->evict(handler->ops_arg, rbnode, evict_arg,
                                        &stop)) {
                        __mmu_int_rb_remove(rbnode, &handler->root);
-                       list_add(&rbnode->list, &del_list);
+                       /* move from LRU list to delete list */
+                       list_move(&rbnode->list, &del_list);
                }
                if (stop)
                        break;
@@ -272,6 +279,7 @@ void hfi1_mmu_rb_remove(struct mmu_rb_handler *handler,
                  node->len);
        spin_lock_irqsave(&handler->lock, flags);
        __mmu_int_rb_remove(node, &handler->root);
+       list_del(&node->list); /* remove from LRU list */
        spin_unlock_irqrestore(&handler->lock, flags);
 
        handler->ops->remove(handler->ops_arg, node);
@@ -311,7 +319,8 @@ static void mmu_notifier_mem_invalidate(struct mmu_notifier *mn,
                          node->addr, node->len);
                if (handler->ops->invalidate(handler->ops_arg, node)) {
                        __mmu_int_rb_remove(node, root);
-                       list_add(&node->list, &handler->del_list);
+                       /* move from LRU list to delete list */
+                       list_move(&node->list, &handler->del_list);
                        added = true;
                }
        }