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 "1.1"
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 /*
70 * The count of operations that complete with tk_status < 0.
71 * These statuses usually indicate error conditions.
72 */
73 unsigned long om_error_status;
74 } ____cacheline_aligned;
75
76 struct rpc_task;
77 struct rpc_clnt;
78
79 /*
80 * EXPORTed functions for managing rpc_iostats structures
81 */
82
83 #ifdef CONFIG_PROC_FS
84
85 struct rpc_iostats * rpc_alloc_iostats(struct rpc_clnt *);
86 void rpc_count_iostats(const struct rpc_task *,
87 struct rpc_iostats *);
88 void rpc_count_iostats_metrics(const struct rpc_task *,
89 struct rpc_iostats *);
90 void rpc_clnt_show_stats(struct seq_file *, struct rpc_clnt *);
91 void rpc_free_iostats(struct rpc_iostats *);
92
93 #else /* CONFIG_PROC_FS */
94
95 static inline struct rpc_iostats *rpc_alloc_iostats(struct rpc_clnt *clnt) { return NULL; }
96 static inline void rpc_count_iostats(const struct rpc_task *task,
97 struct rpc_iostats *stats) {}
98 static inline void rpc_count_iostats_metrics(const struct rpc_task *task,
99 struct rpc_iostats *stats)
100 {
101 }
102
103 static inline void rpc_clnt_show_stats(struct seq_file *seq, struct rpc_clnt *clnt) {}
104 static inline void rpc_free_iostats(struct rpc_iostats *stats) {}
105
106 #endif /* CONFIG_PROC_FS */
107
108 #endif /* _LINUX_SUNRPC_METRICS_H */