Messages in this thread Patch in this message | | | Date | Thu, 2 Mar 2006 18:51:26 +0100 | From | Frederik Deweerdt <> | Subject | Re: Deadlock in net/sunrpc/sched.c |
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(Added Trond Myklebust to the cc list, as he's working on sunrpc) > + if (RPC_IS_QUEUED(task)) { > + struct rpc_wait_queue *queue = task->u.tk_wait.rpc_waitq; > + spin_lock_bh(&queue->lock); > + if (rpc_start_wakeup(task)) { We may end up list_del'ing a task that is not queued anymore: we may be interrupted just after the RPC_IS_QUEUED test. Don't you think this patch could be enough?
--- linux-2.6.16-rc5/net/sunrpc/sched.c 2006-03-01 11:26:15.000000000 +0100 +++ linux-2.6.16-rc5-2/net/sunrpc/sched.c 2006-03-02 15:43:18.000000000 +0100 @@ -521,8 +521,7 @@ spin_lock_bh(&queue->lock); head = &queue->tasks[queue->maxpriority]; for (;;) { - while (!list_empty(head)) { - task = list_entry(head->next, struct rpc_task, u.tk_wait.list); + list_for_each_entry(task, head, u.tk_wait.list) { __rpc_wake_up_task(task); } if (head == &queue->tasks[0]) We don't need to __rpc_wake_up_task a task that is already rpc_start_wakeup'ed after all. BTW, there are other while (!list_empty(head)) on sched.c that could need a similar rewrite.
Regards, Frederik - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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