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authorChuck Lever <chuck.lever@oracle.com>2014-05-28 10:34:49 -0400
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2014-06-04 08:56:51 -0400
commit4f4cf5ad6fc1b16dc8dc9d750bb80b35eba5e98d (patch)
tree752787b1b79b4d7c076883434bcc5650e168d1cb /net/sunrpc/xprt.c
parent18906972aa1103c07869c9b43860a52e0e27e8e5 (diff)
SUNRPC: Move congestion window constants to header file
I would like to use one of the RPC client's congestion algorithm constants in transport-specific code. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net/sunrpc/xprt.c')
-rw-r--r--net/sunrpc/xprt.c28
1 files changed, 9 insertions, 19 deletions
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index d173f79947c6..2d1d5a643b95 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -71,24 +71,6 @@ static void xprt_destroy(struct rpc_xprt *xprt);
71static DEFINE_SPINLOCK(xprt_list_lock); 71static DEFINE_SPINLOCK(xprt_list_lock);
72static LIST_HEAD(xprt_list); 72static LIST_HEAD(xprt_list);
73 73
74/*
75 * The transport code maintains an estimate on the maximum number of out-
76 * standing RPC requests, using a smoothed version of the congestion
77 * avoidance implemented in 44BSD. This is basically the Van Jacobson
78 * congestion algorithm: If a retransmit occurs, the congestion window is
79 * halved; otherwise, it is incremented by 1/cwnd when
80 *
81 * - a reply is received and
82 * - a full number of requests are outstanding and
83 * - the congestion window hasn't been updated recently.
84 */
85#define RPC_CWNDSHIFT (8U)
86#define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT)
87#define RPC_INITCWND RPC_CWNDSCALE
88#define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT)
89
90#define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
91
92/** 74/**
93 * xprt_register_transport - register a transport implementation 75 * xprt_register_transport - register a transport implementation
94 * @transport: transport to register 76 * @transport: transport to register
@@ -446,7 +428,15 @@ EXPORT_SYMBOL_GPL(xprt_release_rqst_cong);
446 * @task: recently completed RPC request used to adjust window 428 * @task: recently completed RPC request used to adjust window
447 * @result: result code of completed RPC request 429 * @result: result code of completed RPC request
448 * 430 *
449 * We use a time-smoothed congestion estimator to avoid heavy oscillation. 431 * The transport code maintains an estimate on the maximum number of out-
432 * standing RPC requests, using a smoothed version of the congestion
433 * avoidance implemented in 44BSD. This is basically the Van Jacobson
434 * congestion algorithm: If a retransmit occurs, the congestion window is
435 * halved; otherwise, it is incremented by 1/cwnd when
436 *
437 * - a reply is received and
438 * - a full number of requests are outstanding and
439 * - the congestion window hasn't been updated recently.
450 */ 440 */
451void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result) 441void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result)
452{ 442{