1/* 2 * linux/include/linux/sunrpc/metrics.h 3 * 4 * Declarations for RPC client per-operation metrics 5 * 6 * Copyright (C) 2005 Chuck Lever <cel@netapp.com> 7 * 8 * RPC client per-operation statistics provide latency and retry 9 * information about each type of RPC procedure in a given RPC program. 10 * These statistics are not for detailed problem diagnosis, but simply 11 * to indicate whether the problem is local or remote. 12 * 13 * These counters are not meant to be human-readable, but are meant to be 14 * integrated into system monitoring tools such as "sar" and "iostat". As 15 * such, the counters are sampled by the tools over time, and are never 16 * zeroed after a file system is mounted. Moving averages can be computed 17 * by the tools by taking the difference between two instantaneous samples 18 * and dividing that by the time between the samples. 19 * 20 * The counters are maintained in a single array per RPC client, indexed 21 * by procedure number. There is no need to maintain separate counter 22 * arrays per-CPU because these counters are always modified behind locks. 23 */ 24 25#ifndef _LINUX_SUNRPC_METRICS_H 26#define _LINUX_SUNRPC_METRICS_H 27 28#include <linux/seq_file.h> 29#include <linux/ktime.h> 30 31#define RPC_IOSTATS_VERS "1.0" 32 33struct rpc_iostats { 34 /* 35 * These counters give an idea about how many request 36 * transmissions are required, on average, to complete that 37 * particular procedure. Some procedures may require more 38 * than one transmission because the server is unresponsive, 39 * the client is retransmitting too aggressively, or the 40 * requests are large and the network is congested. 41 */ 42 unsigned long om_ops, /* count of operations */ 43 om_ntrans, /* count of RPC transmissions */ 44 om_timeouts; /* count of major timeouts */ 45 46 /* 47 * These count how many bytes are sent and received for a 48 * given RPC procedure type. This indicates how much load a 49 * particular procedure is putting on the network. These 50 * counts include the RPC and ULP headers, and the request 51 * payload. 52 */ 53 unsigned long long om_bytes_sent, /* count of bytes out */ 54 om_bytes_recv; /* count of bytes in */ 55 56 /* 57 * The length of time an RPC request waits in queue before 58 * transmission, the network + server latency of the request, 59 * and the total time the request spent from init to release 60 * are measured. 61 */ 62 ktime_t om_queue, /* queued for xmit */ 63 om_rtt, /* RPC RTT */ 64 om_execute; /* RPC execution */ 65} ____cacheline_aligned; 66 67struct rpc_task; 68struct rpc_clnt; 69 70/* 71 * EXPORTed functions for managing rpc_iostats structures 72 */ 73 74#ifdef CONFIG_PROC_FS 75 76struct rpc_iostats * rpc_alloc_iostats(struct rpc_clnt *); 77void rpc_count_iostats(const struct rpc_task *, 78 struct rpc_iostats *); 79void rpc_print_iostats(struct seq_file *, struct rpc_clnt *); 80void rpc_free_iostats(struct rpc_iostats *); 81 82#else /* CONFIG_PROC_FS */ 83 84static inline struct rpc_iostats *rpc_alloc_iostats(struct rpc_clnt *clnt) { return NULL; } 85static inline void rpc_count_iostats(const struct rpc_task *task, 86 struct rpc_iostats *stats) {} 87static inline void rpc_print_iostats(struct seq_file *seq, struct rpc_clnt *clnt) {} 88static inline void rpc_free_iostats(struct rpc_iostats *stats) {} 89 90#endif /* CONFIG_PROC_FS */ 91 92#endif /* _LINUX_SUNRPC_METRICS_H */ 93