Commit 4f4cf5ad authored by Chuck Lever's avatar Chuck Lever Committed by Anna Schumaker
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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: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 18906972

include/linux/sunrpc/xprt.h

+6 −0
Original line number Diff line number Diff line
@@ -24,6 +24,12 @@ 
#define RPC_MAX_SLOT_TABLE_LIMIT	(65536U)

#define RPC_MAX_SLOT_TABLE	RPC_MAX_SLOT_TABLE_LIMIT



#define RPC_CWNDSHIFT		(8U)

#define RPC_CWNDSCALE		(1U << RPC_CWNDSHIFT)

#define RPC_INITCWND		RPC_CWNDSCALE

#define RPC_MAXCWND(xprt)	((xprt)->max_reqs << RPC_CWNDSHIFT)

#define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)



/*

 * This describes a timeout strategy

 */

net/sunrpc/xprt.c

+9 −19
Original line number Diff line number Diff line
@@ -71,24 +71,6 @@ static void xprt_destroy(struct rpc_xprt *xprt); 
static DEFINE_SPINLOCK(xprt_list_lock);

static LIST_HEAD(xprt_list);



/*

 * The transport code maintains an estimate on the maximum number of out-

 * standing RPC requests, using a smoothed version of the congestion

 * avoidance implemented in 44BSD. This is basically the Van Jacobson

 * congestion algorithm: If a retransmit occurs, the congestion window is

 * halved; otherwise, it is incremented by 1/cwnd when

 *

 *	-	a reply is received and

 *	-	a full number of requests are outstanding and

 *	-	the congestion window hasn't been updated recently.

 */

#define RPC_CWNDSHIFT		(8U)

#define RPC_CWNDSCALE		(1U << RPC_CWNDSHIFT)

#define RPC_INITCWND		RPC_CWNDSCALE

#define RPC_MAXCWND(xprt)	((xprt)->max_reqs << RPC_CWNDSHIFT)



#define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)



/**

 * xprt_register_transport - register a transport implementation

 * @transport: transport to register
@@ -446,7 +428,15 @@ EXPORT_SYMBOL_GPL(xprt_release_rqst_cong); 
 * @task: recently completed RPC request used to adjust window

 * @result: result code of completed RPC request

 *

 * We use a time-smoothed congestion estimator to avoid heavy oscillation.

 * The transport code maintains an estimate on the maximum number of out-

 * standing RPC requests, using a smoothed version of the congestion

 * avoidance implemented in 44BSD. This is basically the Van Jacobson

 * congestion algorithm: If a retransmit occurs, the congestion window is

 * halved; otherwise, it is incremented by 1/cwnd when

 *

 *	-	a reply is received and

 *	-	a full number of requests are outstanding and

 *	-	the congestion window hasn't been updated recently.

 */

void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result)

{