SUNRPC: Switch tasks to using the rpc_waitqueue's timer function

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 11 insertions, 58 deletions

diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index 7751d3a05497..0d7be1642dc0 100644
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -67,12 +67,6 @@ struct rpc_task {
         const struct rpc_call_ops *tk_ops;
         void *                  tk_calldata;
 
-        /*
-         * tk_timer is used for async processing by the RPC scheduling
-         * primitives. You should not access this directly unless
-         * you have a pathological interest in kernel oopses.
-         */
-        struct timer_list       tk_timer;       /* kernel timer */
         unsigned long           tk_timeout;     /* timeout for rpc_sleep() */
         unsigned short          tk_flags;       /* misc flags */
         unsigned long           tk_runstate;    /* Task run status */
@@ -149,8 +143,7 @@ struct rpc_task_setup {
 #define RPC_TASK_RUNNING        0
 #define RPC_TASK_QUEUED         1
 #define RPC_TASK_WAKEUP         2
-#define RPC_TASK_HAS_TIMER      3
-#define RPC_TASK_ACTIVE         4
+#define RPC_TASK_ACTIVE         3
 
 #define RPC_IS_RUNNING(t)       test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
 #define rpc_set_running(t)      set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate)
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 29b1c1441f4d..043eef4c15a2 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -58,13 +58,15 @@ struct workqueue_struct *rpciod_workqueue;
  * rpc_run_timer().
  */
 static void
-__rpc_disable_timer(struct rpc_task *task)
+__rpc_disable_timer(struct rpc_wait_queue *queue, struct rpc_task *task)
 {
         if (task->tk_timeout == 0)
                 return;
         dprintk("RPC: %5u disabling timer\n", task->tk_pid);
         task->tk_timeout = 0;
         list_del(&task->u.tk_wait.timer_list);
+        if (list_empty(&queue->timer_list.list))
+                del_timer(&queue->timer_list.timer);
 }
 
 static void
@@ -78,7 +80,7 @@ rpc_set_queue_timer(struct rpc_wait_queue *queue, unsigned long expires)
  * Set up a timer for the current task.
  */
 static void
-__rpc_add_timer(struct rpc_task *task)
+__rpc_add_timer(struct rpc_wait_queue *queue, struct rpc_task *task)
 {
         if (!task->tk_timeout)
                 return;
@@ -86,23 +88,10 @@ __rpc_add_timer(struct rpc_task *task)
         dprintk("RPC: %5u setting alarm for %lu ms\n",
                         task->tk_pid, task->tk_timeout * 1000 / HZ);
 
-        set_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate);
-        mod_timer(&task->tk_timer, jiffies + task->tk_timeout);
-}
-
-/*
- * Delete any timer for the current task. Because we use del_timer_sync(),
- * this function should never be called while holding queue->lock.
- */
-static void
-rpc_delete_timer(struct rpc_task *task)
-{
-        if (RPC_IS_QUEUED(task))
-                return;
-        if (test_and_clear_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate)) {
-                del_singleshot_timer_sync(&task->tk_timer);
-                dprintk("RPC: %5u deleting timer\n", task->tk_pid);
-        }
+        task->u.tk_wait.expires = jiffies + task->tk_timeout;
+        if (list_empty(&queue->timer_list.list) || time_before(task->u.tk_wait.expires, queue->timer_list.expires))
+                rpc_set_queue_timer(queue, task->u.tk_wait.expires);
+        list_add(&task->u.tk_wait.timer_list, &queue->timer_list.list);
 }
 
 /*
@@ -172,7 +161,7 @@ static void __rpc_remove_wait_queue_priority(struct rpc_task *task)
  */
 static void __rpc_remove_wait_queue(struct rpc_wait_queue *queue, struct rpc_task *task)
 {
-        __rpc_disable_timer(task);
+        __rpc_disable_timer(queue, task);
         if (RPC_IS_PRIORITY(queue))
                 __rpc_remove_wait_queue_priority(task);
         list_del(&task->u.tk_wait.list);
@@ -344,7 +333,7 @@ static void __rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
 
         BUG_ON(task->tk_callback != NULL);
         task->tk_callback = action;
-        __rpc_add_timer(task);
+        __rpc_add_timer(q, task);
 }
 
 void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
@@ -555,26 +544,6 @@ void rpc_wake_up_status(struct rpc_wait_queue *queue, int status)
 }
 EXPORT_SYMBOL_GPL(rpc_wake_up_status);
 
-/*
- * Run a timeout function.
- */
-static void rpc_run_timer(unsigned long ptr)
-{
-        struct rpc_task *task = (struct rpc_task *)ptr;
-        struct rpc_wait_queue *queue = task->tk_waitqueue;
-
-        spin_lock(&queue->lock);
-        if (RPC_IS_QUEUED(task) && task->tk_waitqueue == queue) {
-                dprintk("RPC: %5u timeout\n", task->tk_pid);
-                task->tk_status = -ETIMEDOUT;
-                rpc_wake_up_task_queue_locked(queue, task);
-        }
-        spin_unlock(&queue->lock);
-        smp_mb__before_clear_bit();
-        clear_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate);
-        smp_mb__after_clear_bit();
-}
-
 static void __rpc_queue_timer_fn(unsigned long ptr)
 {
         struct rpc_wait_queue *queue = (struct rpc_wait_queue *)ptr;
@@ -586,7 +555,6 @@ static void __rpc_queue_timer_fn(unsigned long ptr)
         list_for_each_entry_safe(task, n, &queue->timer_list.list, u.tk_wait.timer_list) {
                 timeo = task->u.tk_wait.expires;
                 if (time_after_eq(now, timeo)) {
-                        list_del_init(&task->u.tk_wait.timer_list);
                         dprintk("RPC: %5u timeout\n", task->tk_pid);
                         task->tk_status = -ETIMEDOUT;
                         rpc_wake_up_task_queue_locked(queue, task);
@@ -666,10 +634,6 @@ static void __rpc_execute(struct rpc_task *task)
         BUG_ON(RPC_IS_QUEUED(task));
 
         for (;;) {
-                /*
-                 * Garbage collection of pending timers...
-                 */
-                rpc_delete_timer(task);
 
                 /*
                  * Execute any pending callback.
@@ -838,7 +802,6 @@ EXPORT_SYMBOL_GPL(rpc_free);
 static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *task_setup_data)
 {
         memset(task, 0, sizeof(*task));
-        setup_timer(&task->tk_timer, rpc_run_timer, (unsigned long)task);
         atomic_set(&task->tk_count, 1);
         task->tk_flags  = task_setup_data->flags;
         task->tk_ops = task_setup_data->callback_ops;
@@ -971,9 +934,6 @@ static void rpc_release_task(struct rpc_task *task)
         }
         BUG_ON (RPC_IS_QUEUED(task));
 
-        /* Synchronously delete any running timer */
-        rpc_delete_timer(task);
-
 #ifdef RPC_DEBUG
         task->tk_magic = 0;
 #endif