From ba60eb25ff6be6f8e60488cdfd454e5c612bce60 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 14 Apr 2013 10:49:37 -0400 Subject: SUNRPC: Fix a livelock problem in the xprt->backlog queue This patch ensures that we throttle new RPC requests if there are requests already waiting in the xprt->backlog queue. The reason for doing this is to fix livelock issues that can occur when an existing (high priority) task is waiting in the backlog queue, gets woken up by xprt_free_slot(), but a new task then steals the slot. Signed-off-by: Trond Myklebust --- include/linux/sunrpc/xprt.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 30834be03011..12815f66a9c4 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -279,6 +279,7 @@ struct xprt_class { struct rpc_xprt *xprt_create_transport(struct xprt_create *args); void xprt_connect(struct rpc_task *task); void xprt_reserve(struct rpc_task *task); +void xprt_retry_reserve(struct rpc_task *task); int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task); int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task); void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task); @@ -334,6 +335,7 @@ int xs_swapper(struct rpc_xprt *xprt, int enable); #define XPRT_CLOSING (6) #define XPRT_CONNECTION_ABORT (7) #define XPRT_CONNECTION_CLOSE (8) +#define XPRT_CONGESTED (9) static inline void xprt_set_connected(struct rpc_xprt *xprt) { -- cgit v1.2.3