1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * linux/include/linux/sunrpc/metrics.h 4 * 5 * Declarations for RPC client per-operation metrics 6 * 7 * Copyright (C) 2005 Chuck Lever <cel@netapp.com> 8 * 9 * RPC client per-operation statistics provide latency and retry 10 * information about each type of RPC procedure in a given RPC program. 11 * These statistics are not for detailed problem diagnosis, but simply 12 * to indicate whether the problem is local or remote. 13 * 14 * These counters are not meant to be human-readable, but are meant to be 15 * integrated into system monitoring tools such as "sar" and "iostat". As 16 * such, the counters are sampled by the tools over time, and are never 17 * zeroed after a file system is mounted. Moving averages can be computed 18 * by the tools by taking the difference between two instantaneous samples 19 * and dividing that by the time between the samples. 20 * 21 * The counters are maintained in a single array per RPC client, indexed 22 * by procedure number. There is no need to maintain separate counter 23 * arrays per-CPU because these counters are always modified behind locks. 24 */ 25 26 #ifndef _LINUX_SUNRPC_METRICS_H 27 #define _LINUX_SUNRPC_METRICS_H 28 29 #include <linux/seq_file.h> 30 #include <linux/ktime.h> 31 #include <linux/spinlock.h> 32 33 #define RPC_IOSTATS_VERS "1.0" 34 35 struct rpc_iostats { 36 spinlock_t om_lock; 37 38 /* 39 * These counters give an idea about how many request 40 * transmissions are required, on average, to complete that 41 * particular procedure. Some procedures may require more 42 * than one transmission because the server is unresponsive, 43 * the client is retransmitting too aggressively, or the 44 * requests are large and the network is congested. 45 */ 46 unsigned long om_ops, /* count of operations */ 47 om_ntrans, /* count of RPC transmissions */ 48 om_timeouts; /* count of major timeouts */ 49 50 /* 51 * These count how many bytes are sent and received for a 52 * given RPC procedure type. This indicates how much load a 53 * particular procedure is putting on the network. These 54 * counts include the RPC and ULP headers, and the request 55 * payload. 56 */ 57 unsigned long long om_bytes_sent, /* count of bytes out */ 58 om_bytes_recv; /* count of bytes in */ 59 60 /* 61 * The length of time an RPC request waits in queue before 62 * transmission, the network + server latency of the request, 63 * and the total time the request spent from init to release 64 * are measured. 65 */ 66 ktime_t om_queue, /* queued for xmit */ 67 om_rtt, /* RPC RTT */ 68 om_execute; /* RPC execution */ 69 } ____cacheline_aligned; 70 71 struct rpc_task; 72 struct rpc_clnt; 73 74 /* 75 * EXPORTed functions for managing rpc_iostats structures 76 */ 77 78 #ifdef CONFIG_PROC_FS 79 80 struct rpc_iostats * rpc_alloc_iostats(struct rpc_clnt *); 81 void rpc_count_iostats(const struct rpc_task *, 82 struct rpc_iostats *); 83 void rpc_count_iostats_metrics(const struct rpc_task *, 84 struct rpc_iostats *); 85 void rpc_clnt_show_stats(struct seq_file *, struct rpc_clnt *); 86 void rpc_free_iostats(struct rpc_iostats *); 87 88 #else /* CONFIG_PROC_FS */ 89 90 static inline struct rpc_iostats *rpc_alloc_iostats(struct rpc_clnt *clnt) { return NULL; } 91 static inline void rpc_count_iostats(const struct rpc_task *task, 92 struct rpc_iostats *stats) {} 93 static inline void rpc_count_iostats_metrics(const struct rpc_task *task, 94 struct rpc_iostats *stats) 95 { 96 } 97 98 static inline void rpc_clnt_show_stats(struct seq_file *seq, struct rpc_clnt *clnt) {} 99 static inline void rpc_free_iostats(struct rpc_iostats *stats) {} 100 101 #endif /* CONFIG_PROC_FS */ 102 103 #endif /* _LINUX_SUNRPC_METRICS_H */ 104