"Myklebust, Trond" <Trond.Myklebust@xxxxxxxxxx> wrote: | Clearly the comment is misleading and should be removed. That write lock | | _is_ needed in order to throttle slots on TCP. | | As far as I know, kernel 3.3 is not in stable support any more, so I | can't help that. Can you reproduce the problem on a 3.5 kernel or | higher? I can easily reproduce the hang on the latest kernel (eeea3ac912) with my script (http://permalink.gmane.org/gmane.linux.nfs/51833). With this change, it doesn't hang: diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index a5a402a..6e739bf 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -1083,20 +1083,9 @@ void xprt_reserve(struct rpc_task *task) if (task->tk_rqstp != NULL) return; - /* Note: grabbing the xprt_lock_write() here is not strictly needed, - * but ensures that we throttle new slot allocation if the transport - * is congested (e.g. if reconnecting or if we're out of socket - * write buffer space). - */ - task->tk_timeout = 0; - task->tk_status = -EAGAIN; - if (!xprt_lock_write(xprt, task)) - return; - spin_lock(&xprt->reserve_lock); xprt_alloc_slot(task); spin_unlock(&xprt->reserve_lock); - xprt_release_write(xprt, task); } static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt) -- Dick -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
