diff options
Diffstat (limited to 'kernel/rcu/tree.c')
| -rw-r--r-- | kernel/rcu/tree.c | 58 |
1 files changed, 36 insertions, 22 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 54963f8c244c..1449cb69a0e0 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2778,7 +2778,7 @@ EXPORT_SYMBOL_GPL(call_rcu); */ struct kvfree_rcu_bulk_data { struct list_head list; - unsigned long gp_snap; + struct rcu_gp_oldstate gp_snap; unsigned long nr_records; void *records[]; }; @@ -2795,6 +2795,7 @@ struct kvfree_rcu_bulk_data { * struct kfree_rcu_cpu_work - single batch of kfree_rcu() requests * @rcu_work: Let queue_rcu_work() invoke workqueue handler after grace period * @head_free: List of kfree_rcu() objects waiting for a grace period + * @head_free_gp_snap: Grace-period snapshot to check for attempted premature frees. * @bulk_head_free: Bulk-List of kvfree_rcu() objects waiting for a grace period * @krcp: Pointer to @kfree_rcu_cpu structure */ @@ -2802,6 +2803,7 @@ struct kvfree_rcu_bulk_data { struct kfree_rcu_cpu_work { struct rcu_work rcu_work; struct rcu_head *head_free; + struct rcu_gp_oldstate head_free_gp_snap; struct list_head bulk_head_free[FREE_N_CHANNELS]; struct kfree_rcu_cpu *krcp; }; @@ -2922,6 +2924,9 @@ drain_page_cache(struct kfree_rcu_cpu *krcp) struct llist_node *page_list, *pos, *n; int freed = 0; + if (!rcu_min_cached_objs) + return 0; + raw_spin_lock_irqsave(&krcp->lock, flags); page_list = llist_del_all(&krcp->bkvcache); WRITE_ONCE(krcp->nr_bkv_objs, 0); @@ -2942,24 +2947,25 @@ kvfree_rcu_bulk(struct kfree_rcu_cpu *krcp, unsigned long flags; int i; - debug_rcu_bhead_unqueue(bnode); - - rcu_lock_acquire(&rcu_callback_map); - if (idx == 0) { // kmalloc() / kfree(). - trace_rcu_invoke_kfree_bulk_callback( - rcu_state.name, bnode->nr_records, - bnode->records); - - kfree_bulk(bnode->nr_records, bnode->records); - } else { // vmalloc() / vfree(). - for (i = 0; i < bnode->nr_records; i++) { - trace_rcu_invoke_kvfree_callback( - rcu_state.name, bnode->records[i], 0); - - vfree(bnode->records[i]); + if (!WARN_ON_ONCE(!poll_state_synchronize_rcu_full(&bnode->gp_snap))) { + debug_rcu_bhead_unqueue(bnode); + rcu_lock_acquire(&rcu_callback_map); + if (idx == 0) { // kmalloc() / kfree(). + trace_rcu_invoke_kfree_bulk_callback( + rcu_state.name, bnode->nr_records, + bnode->records); + + kfree_bulk(bnode->nr_records, bnode->records); + } else { // vmalloc() / vfree(). + for (i = 0; i < bnode->nr_records; i++) { + trace_rcu_invoke_kvfree_callback( + rcu_state.name, bnode->records[i], 0); + + vfree(bnode->records[i]); + } } + rcu_lock_release(&rcu_callback_map); } - rcu_lock_release(&rcu_callback_map); raw_spin_lock_irqsave(&krcp->lock, flags); if (put_cached_bnode(krcp, bnode)) @@ -3006,6 +3012,7 @@ static void kfree_rcu_work(struct work_struct *work) struct rcu_head *head; struct kfree_rcu_cpu *krcp; struct kfree_rcu_cpu_work *krwp; + struct rcu_gp_oldstate head_gp_snap; int i; krwp = container_of(to_rcu_work(work), @@ -3020,6 +3027,7 @@ static void kfree_rcu_work(struct work_struct *work) // Channel 3. head = krwp->head_free; krwp->head_free = NULL; + head_gp_snap = krwp->head_free_gp_snap; raw_spin_unlock_irqrestore(&krcp->lock, flags); // Handle the first two channels. @@ -3036,7 +3044,8 @@ static void kfree_rcu_work(struct work_struct *work) * queued on a linked list through their rcu_head structures. * This list is named "Channel 3". */ - kvfree_rcu_list(head); + if (head && !WARN_ON_ONCE(!poll_state_synchronize_rcu_full(&head_gp_snap))) + kvfree_rcu_list(head); } static bool @@ -3103,7 +3112,7 @@ kvfree_rcu_drain_ready(struct kfree_rcu_cpu *krcp) INIT_LIST_HEAD(&bulk_ready[i]); list_for_each_entry_safe_reverse(bnode, n, &krcp->bulk_head[i], list) { - if (!poll_state_synchronize_rcu(bnode->gp_snap)) + if (!poll_state_synchronize_rcu_full(&bnode->gp_snap)) break; atomic_sub(bnode->nr_records, &krcp->bulk_count[i]); @@ -3168,6 +3177,7 @@ static void kfree_rcu_monitor(struct work_struct *work) // objects queued on the linked list. if (!krwp->head_free) { krwp->head_free = krcp->head; + get_state_synchronize_rcu_full(&krwp->head_free_gp_snap); atomic_set(&krcp->head_count, 0); WRITE_ONCE(krcp->head, NULL); } @@ -3216,7 +3226,7 @@ static void fill_page_cache_func(struct work_struct *work) nr_pages = atomic_read(&krcp->backoff_page_cache_fill) ? 1 : rcu_min_cached_objs; - for (i = 0; i < nr_pages; i++) { + for (i = READ_ONCE(krcp->nr_bkv_objs); i < nr_pages; i++) { bnode = (struct kvfree_rcu_bulk_data *) __get_free_page(GFP_KERNEL | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); @@ -3240,6 +3250,10 @@ static void fill_page_cache_func(struct work_struct *work) static void run_page_cache_worker(struct kfree_rcu_cpu *krcp) { + // If cache disabled, bail out. + if (!rcu_min_cached_objs) + return; + if (rcu_scheduler_active == RCU_SCHEDULER_RUNNING && !atomic_xchg(&krcp->work_in_progress, 1)) { if (atomic_read(&krcp->backoff_page_cache_fill)) { @@ -3294,7 +3308,7 @@ add_ptr_to_bulk_krc_lock(struct kfree_rcu_cpu **krcp, // scenarios. bnode = (struct kvfree_rcu_bulk_data *) __get_free_page(GFP_KERNEL | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); - *krcp = krc_this_cpu_lock(flags); + raw_spin_lock_irqsave(&(*krcp)->lock, *flags); } if (!bnode) @@ -3307,7 +3321,7 @@ add_ptr_to_bulk_krc_lock(struct kfree_rcu_cpu **krcp, // Finally insert and update the GP for this page. bnode->records[bnode->nr_records++] = ptr; - bnode->gp_snap = get_state_synchronize_rcu(); + get_state_synchronize_rcu_full(&bnode->gp_snap); atomic_inc(&(*krcp)->bulk_count[idx]); return true; |