From 11c556b3d8d481829ab5f9933a25d29b00913b5a Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Mon, 20 Mar 2006 13:44:22 -0500 Subject: SUNRPC: provide a mechanism for collecting stats in the RPC client Add a simple mechanism for collecting stats in the RPC client. Stats are tabulated during xprt_release. Note that per_cpu shenanigans are not required here because the RPC client already serializes on the transport write lock. Test plan: Compile kernel with CONFIG_NFS enabled. Basic performance regression testing with high-speed networking and high performance server. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- include/linux/sunrpc/clnt.h | 3 +- include/linux/sunrpc/metrics.h | 77 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 79 insertions(+), 1 deletion(-) create mode 100644 include/linux/sunrpc/metrics.h (limited to 'include/linux/sunrpc') diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h index f147e6b84332..0f3662002ffc 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -45,7 +45,8 @@ struct rpc_clnt { char * cl_server; /* server machine name */ char * cl_protname; /* protocol name */ struct rpc_auth * cl_auth; /* authenticator */ - struct rpc_stat * cl_stats; /* statistics */ + struct rpc_stat * cl_stats; /* per-program statistics */ + struct rpc_iostats * cl_metrics; /* per-client statistics */ unsigned int cl_softrtry : 1,/* soft timeouts */ cl_intr : 1,/* interruptible */ diff --git a/include/linux/sunrpc/metrics.h b/include/linux/sunrpc/metrics.h new file mode 100644 index 000000000000..8f96e9dc369a --- /dev/null +++ b/include/linux/sunrpc/metrics.h @@ -0,0 +1,77 @@ +/* + * linux/include/linux/sunrpc/metrics.h + * + * Declarations for RPC client per-operation metrics + * + * Copyright (C) 2005 Chuck Lever + * + * RPC client per-operation statistics provide latency and retry + * information about each type of RPC procedure in a given RPC program. + * These statistics are not for detailed problem diagnosis, but simply + * to indicate whether the problem is local or remote. + * + * These counters are not meant to be human-readable, but are meant to be + * integrated into system monitoring tools such as "sar" and "iostat". As + * such, the counters are sampled by the tools over time, and are never + * zeroed after a file system is mounted. Moving averages can be computed + * by the tools by taking the difference between two instantaneous samples + * and dividing that by the time between the samples. + * + * The counters are maintained in a single array per RPC client, indexed + * by procedure number. There is no need to maintain separate counter + * arrays per-CPU because these counters are always modified behind locks. + */ + +#ifndef _LINUX_SUNRPC_METRICS_H +#define _LINUX_SUNRPC_METRICS_H + +#include + +#define RPC_IOSTATS_VERS "1.0" + +struct rpc_iostats { + /* + * These counters give an idea about how many request + * transmissions are required, on average, to complete that + * particular procedure. Some procedures may require more + * than one transmission because the server is unresponsive, + * the client is retransmitting too aggressively, or the + * requests are large and the network is congested. + */ + unsigned long om_ops, /* count of operations */ + om_ntrans, /* count of RPC transmissions */ + om_timeouts; /* count of major timeouts */ + + /* + * These count how many bytes are sent and received for a + * given RPC procedure type. This indicates how much load a + * particular procedure is putting on the network. These + * counts include the RPC and ULP headers, and the request + * payload. + */ + unsigned long long om_bytes_sent, /* count of bytes out */ + om_bytes_recv; /* count of bytes in */ + + /* + * The length of time an RPC request waits in queue before + * transmission, the network + server latency of the request, + * and the total time the request spent from init to release + * are measured. + */ + unsigned long long om_queue, /* jiffies queued for xmit */ + om_rtt, /* jiffies for RPC RTT */ + om_execute; /* jiffies for RPC execution */ +} ____cacheline_aligned; + +struct rpc_task; +struct rpc_clnt; + +/* + * EXPORTed functions for managing rpc_iostats structures + */ +struct rpc_iostats * rpc_alloc_iostats(struct rpc_clnt *); +void rpc_count_iostats(struct rpc_task *); +void rpc_print_iostats(struct seq_file *, struct rpc_clnt *); +void rpc_free_iostats(struct rpc_iostats *); + +#endif /* _LINUX_SUNRPC_METRICS_H */ -- cgit v1.2.2