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Diffstat (limited to 'net/sunrpc/sched.c')
-rw-r--r--net/sunrpc/sched.c30
1 files changed, 25 insertions, 5 deletions
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index b4133bd13915..f8529fc8e542 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -98,9 +98,25 @@ __rpc_add_timer(struct rpc_wait_queue *queue, struct rpc_task *task)
list_add(&task->u.tk_wait.timer_list, &queue->timer_list.list);
}
+static void rpc_rotate_queue_owner(struct rpc_wait_queue *queue)
+{
+ struct list_head *q = &queue->tasks[queue->priority];
+ struct rpc_task *task;
+
+ if (!list_empty(q)) {
+ task = list_first_entry(q, struct rpc_task, u.tk_wait.list);
+ if (task->tk_owner == queue->owner)
+ list_move_tail(&task->u.tk_wait.list, q);
+ }
+}
+
static void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int priority)
{
- queue->priority = priority;
+ if (queue->priority != priority) {
+ /* Fairness: rotate the list when changing priority */
+ rpc_rotate_queue_owner(queue);
+ queue->priority = priority;
+ }
}
static void rpc_set_waitqueue_owner(struct rpc_wait_queue *queue, pid_t pid)
@@ -164,6 +180,8 @@ static void __rpc_add_wait_queue(struct rpc_wait_queue *queue,
list_add_tail(&task->u.tk_wait.list, &queue->tasks[0]);
task->tk_waitqueue = queue;
queue->qlen++;
+ /* barrier matches the read in rpc_wake_up_task_queue_locked() */
+ smp_wmb();
rpc_set_queued(task);
dprintk("RPC: %5u added to queue %p \"%s\"\n",
@@ -414,8 +432,11 @@ static void __rpc_do_wake_up_task(struct rpc_wait_queue *queue, struct rpc_task
*/
static void rpc_wake_up_task_queue_locked(struct rpc_wait_queue *queue, struct rpc_task *task)
{
- if (RPC_IS_QUEUED(task) && task->tk_waitqueue == queue)
- __rpc_do_wake_up_task(queue, task);
+ if (RPC_IS_QUEUED(task)) {
+ smp_rmb();
+ if (task->tk_waitqueue == queue)
+ __rpc_do_wake_up_task(queue, task);
+ }
}
/*
@@ -972,8 +993,7 @@ static void rpc_async_release(struct work_struct *work)
static void rpc_release_resources_task(struct rpc_task *task)
{
- if (task->tk_rqstp)
- xprt_release(task);
+ xprt_release(task);
if (task->tk_msg.rpc_cred) {
put_rpccred(task->tk_msg.rpc_cred);
task->tk_msg.rpc_cred = NULL;