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
33 struct 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
67 struct rpc_task;
68 struct rpc_clnt;
69
70 /*
71 * EXPORTed functions for managing rpc_iostats structures
72 */
73
74 #ifdef CONFIG_PROC_FS
75
76 struct rpc_iostats * rpc_alloc_iostats(struct rpc_clnt *);
77 void rpc_count_iostats(const struct rpc_task *,
78 struct rpc_iostats *);
79 void rpc_print_iostats(struct seq_file *, struct rpc_clnt *);
80 void rpc_free_iostats(struct rpc_iostats *);
81
82 #else /* CONFIG_PROC_FS */
83
rpc_alloc_iostats(struct rpc_clnt * clnt)84 static inline struct rpc_iostats *rpc_alloc_iostats(struct rpc_clnt *clnt) { return NULL; }
rpc_count_iostats(const struct rpc_task * task,struct rpc_iostats * stats)85 static inline void rpc_count_iostats(const struct rpc_task *task,
86 struct rpc_iostats *stats) {}
rpc_print_iostats(struct seq_file * seq,struct rpc_clnt * clnt)87 static inline void rpc_print_iostats(struct seq_file *seq, struct rpc_clnt *clnt) {}
rpc_free_iostats(struct rpc_iostats * stats)88 static inline void rpc_free_iostats(struct rpc_iostats *stats) {}
89
90 #endif /* CONFIG_PROC_FS */
91
92 #endif /* _LINUX_SUNRPC_METRICS_H */
93