Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-ig0-f175.google.com ([209.85.213.175]:54017 "EHLO mail-ig0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932133AbaE1Oev (ORCPT ); Wed, 28 May 2014 10:34:51 -0400 From: Chuck Lever Subject: [PATCH v5 21/24] SUNRPC: Move congestion window constants to header file To: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org Cc: Anna.Schumaker@netapp.com Date: Wed, 28 May 2014 10:34:49 -0400 Message-ID: <20140528143449.23214.29020.stgit@manet.1015granger.net> In-Reply-To: <20140528142521.23214.39655.stgit@manet.1015granger.net> References: <20140528142521.23214.39655.stgit@manet.1015granger.net> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: I would like to use one of the RPC client's congestion algorithm constants in transport-specific code. Signed-off-by: Chuck Lever --- include/linux/sunrpc/xprt.h | 6 ++++++ net/sunrpc/xprt.c | 28 +++++++++------------------- 2 files changed, 15 insertions(+), 19 deletions(-) diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 3e5efb2..5903d2c 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -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 */ diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index d173f79..2d1d5a6 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -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) {