Chuck Lever | d9ef5a8 | 2006-03-20 13:44:13 -0500 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/nfs/iostat.h |
| 3 | * |
| 4 | * Declarations for NFS client per-mount statistics |
| 5 | * |
| 6 | * Copyright (C) 2005, 2006 Chuck Lever <cel@netapp.com> |
| 7 | * |
| 8 | * NFS client per-mount statistics provide information about the health of |
| 9 | * the NFS client and the health of each NFS mount point. Generally these |
| 10 | * are not for detailed problem diagnosis, but simply to indicate that there |
| 11 | * is a problem. |
| 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 | |
| 21 | #ifndef _NFS_IOSTAT |
| 22 | #define _NFS_IOSTAT |
| 23 | |
| 24 | #define NFS_IOSTAT_VERS "1.0" |
| 25 | |
| 26 | /* |
| 27 | * NFS byte counters |
| 28 | * |
| 29 | * 1. SERVER - the number of payload bytes read from or written to the |
| 30 | * server by the NFS client via an NFS READ or WRITE request. |
| 31 | * |
| 32 | * 2. NORMAL - the number of bytes read or written by applications via |
| 33 | * the read(2) and write(2) system call interfaces. |
| 34 | * |
| 35 | * 3. DIRECT - the number of bytes read or written from files opened |
| 36 | * with the O_DIRECT flag. |
| 37 | * |
| 38 | * These counters give a view of the data throughput into and out of the NFS |
| 39 | * client. Comparing the number of bytes requested by an application with the |
| 40 | * number of bytes the client requests from the server can provide an |
| 41 | * indication of client efficiency (per-op, cache hits, etc). |
| 42 | * |
| 43 | * These counters can also help characterize which access methods are in |
| 44 | * use. DIRECT by itself shows whether there is any O_DIRECT traffic. |
| 45 | * NORMAL + DIRECT shows how much data is going through the system call |
| 46 | * interface. A large amount of SERVER traffic without much NORMAL or |
| 47 | * DIRECT traffic shows that applications are using mapped files. |
| 48 | * |
| 49 | * NFS page counters |
| 50 | * |
| 51 | * These count the number of pages read or written via nfs_readpage(), |
| 52 | * nfs_readpages(), or their write equivalents. |
| 53 | */ |
| 54 | enum nfs_stat_bytecounters { |
| 55 | NFSIOS_NORMALREADBYTES = 0, |
| 56 | NFSIOS_NORMALWRITTENBYTES, |
| 57 | NFSIOS_DIRECTREADBYTES, |
| 58 | NFSIOS_DIRECTWRITTENBYTES, |
| 59 | NFSIOS_SERVERREADBYTES, |
| 60 | NFSIOS_SERVERWRITTENBYTES, |
| 61 | NFSIOS_READPAGES, |
| 62 | NFSIOS_WRITEPAGES, |
| 63 | __NFSIOS_BYTESMAX, |
| 64 | }; |
| 65 | |
| 66 | /* |
| 67 | * NFS event counters |
| 68 | * |
| 69 | * These counters provide a low-overhead way of monitoring client activity |
| 70 | * without enabling NFS trace debugging. The counters show the rate at |
| 71 | * which VFS requests are made, and how often the client invalidates its |
| 72 | * data and attribute caches. This allows system administrators to monitor |
| 73 | * such things as how close-to-open is working, and answer questions such |
| 74 | * as "why are there so many GETATTR requests on the wire?" |
| 75 | * |
| 76 | * They also count anamolous events such as short reads and writes, silly |
| 77 | * renames due to close-after-delete, and operations that change the size |
| 78 | * of a file (such operations can often be the source of data corruption |
| 79 | * if applications aren't using file locking properly). |
| 80 | */ |
| 81 | enum nfs_stat_eventcounters { |
| 82 | NFSIOS_INODEREVALIDATE = 0, |
| 83 | NFSIOS_DENTRYREVALIDATE, |
| 84 | NFSIOS_DATAINVALIDATE, |
| 85 | NFSIOS_ATTRINVALIDATE, |
| 86 | NFSIOS_VFSOPEN, |
| 87 | NFSIOS_VFSLOOKUP, |
| 88 | NFSIOS_VFSACCESS, |
| 89 | NFSIOS_VFSUPDATEPAGE, |
| 90 | NFSIOS_VFSREADPAGE, |
| 91 | NFSIOS_VFSREADPAGES, |
| 92 | NFSIOS_VFSWRITEPAGE, |
| 93 | NFSIOS_VFSWRITEPAGES, |
| 94 | NFSIOS_VFSGETDENTS, |
| 95 | NFSIOS_VFSSETATTR, |
| 96 | NFSIOS_VFSFLUSH, |
| 97 | NFSIOS_VFSFSYNC, |
| 98 | NFSIOS_VFSLOCK, |
| 99 | NFSIOS_VFSRELEASE, |
| 100 | NFSIOS_CONGESTIONWAIT, |
| 101 | NFSIOS_SETATTRTRUNC, |
| 102 | NFSIOS_EXTENDWRITE, |
| 103 | NFSIOS_SILLYRENAME, |
| 104 | NFSIOS_SHORTREAD, |
| 105 | NFSIOS_SHORTWRITE, |
Chuck Lever | 006ea73 | 2006-03-20 13:44:14 -0500 | [diff] [blame] | 106 | NFSIOS_DELAY, |
Chuck Lever | d9ef5a8 | 2006-03-20 13:44:13 -0500 | [diff] [blame] | 107 | __NFSIOS_COUNTSMAX, |
| 108 | }; |
| 109 | |
| 110 | #ifdef __KERNEL__ |
| 111 | |
| 112 | #include <linux/percpu.h> |
| 113 | #include <linux/cache.h> |
| 114 | |
| 115 | struct nfs_iostats { |
| 116 | unsigned long long bytes[__NFSIOS_BYTESMAX]; |
| 117 | unsigned long events[__NFSIOS_COUNTSMAX]; |
| 118 | } ____cacheline_aligned; |
| 119 | |
Chuck Lever | 006ea73 | 2006-03-20 13:44:14 -0500 | [diff] [blame] | 120 | static inline void nfs_inc_server_stats(struct nfs_server *server, enum nfs_stat_eventcounters stat) |
Chuck Lever | d9ef5a8 | 2006-03-20 13:44:13 -0500 | [diff] [blame] | 121 | { |
| 122 | struct nfs_iostats *iostats; |
| 123 | int cpu; |
| 124 | |
| 125 | cpu = get_cpu(); |
Chuck Lever | 006ea73 | 2006-03-20 13:44:14 -0500 | [diff] [blame] | 126 | iostats = per_cpu_ptr(server->io_stats, cpu); |
Chuck Lever | d9ef5a8 | 2006-03-20 13:44:13 -0500 | [diff] [blame] | 127 | iostats->events[stat] ++; |
| 128 | put_cpu_no_resched(); |
| 129 | } |
| 130 | |
Chuck Lever | 006ea73 | 2006-03-20 13:44:14 -0500 | [diff] [blame] | 131 | static inline void nfs_inc_stats(struct inode *inode, enum nfs_stat_eventcounters stat) |
| 132 | { |
| 133 | nfs_inc_server_stats(NFS_SERVER(inode), stat); |
| 134 | } |
| 135 | |
| 136 | static inline void nfs_add_server_stats(struct nfs_server *server, enum nfs_stat_bytecounters stat, unsigned long addend) |
| 137 | { |
| 138 | struct nfs_iostats *iostats; |
| 139 | int cpu; |
| 140 | |
| 141 | cpu = get_cpu(); |
| 142 | iostats = per_cpu_ptr(server->io_stats, cpu); |
| 143 | iostats->bytes[stat] += addend; |
| 144 | put_cpu_no_resched(); |
| 145 | } |
| 146 | |
Chuck Lever | d9ef5a8 | 2006-03-20 13:44:13 -0500 | [diff] [blame] | 147 | static inline void nfs_add_stats(struct inode *inode, enum nfs_stat_bytecounters stat, unsigned long addend) |
| 148 | { |
Chuck Lever | 006ea73 | 2006-03-20 13:44:14 -0500 | [diff] [blame] | 149 | nfs_add_server_stats(NFS_SERVER(inode), stat, addend); |
Chuck Lever | d9ef5a8 | 2006-03-20 13:44:13 -0500 | [diff] [blame] | 150 | } |
| 151 | |
| 152 | static inline struct nfs_iostats *nfs_alloc_iostats(void) |
| 153 | { |
| 154 | return alloc_percpu(struct nfs_iostats); |
| 155 | } |
| 156 | |
| 157 | static inline void nfs_free_iostats(struct nfs_iostats *stats) |
| 158 | { |
| 159 | free_percpu(stats); |
| 160 | } |
| 161 | |
| 162 | #endif |
| 163 | #endif |