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Diffstat (limited to 'include/linux/nfs_iostat.h')
| -rw-r--r-- | include/linux/nfs_iostat.h | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/include/linux/nfs_iostat.h b/include/linux/nfs_iostat.h new file mode 100644 index 00000000000..1cb9a3fed2b --- /dev/null +++ b/include/linux/nfs_iostat.h @@ -0,0 +1,119 @@ +/* + * User-space visible declarations for NFS client per-mount + * point statistics + * + * Copyright (C) 2005, 2006 Chuck Lever <cel@netapp.com> + * + * NFS client per-mount statistics provide information about the + * health of the NFS client and the health of each NFS mount point. + * Generally these are not for detailed problem diagnosis, but + * simply to indicate that there is a problem. + * + * These counters are not meant to be human-readable, but are meant + * to be integrated into system monitoring tools such as "sar" and + * "iostat". As such, the counters are sampled by the tools over + * time, and are never zeroed after a file system is mounted. + * Moving averages can be computed by the tools by taking the + * difference between two instantaneous samples and dividing that + * by the time between the samples. + */ + +#ifndef _LINUX_NFS_IOSTAT +#define _LINUX_NFS_IOSTAT + +#define NFS_IOSTAT_VERS "1.0" + +/* + * NFS byte counters + * + * 1. SERVER - the number of payload bytes read from or written + * to the server by the NFS client via an NFS READ or WRITE + * request. + * + * 2. NORMAL - the number of bytes read or written by applications + * via the read(2) and write(2) system call interfaces. + * + * 3. DIRECT - the number of bytes read or written from files + * opened with the O_DIRECT flag. + * + * These counters give a view of the data throughput into and out + * of the NFS client. Comparing the number of bytes requested by + * an application with the number of bytes the client requests from + * the server can provide an indication of client efficiency + * (per-op, cache hits, etc). + * + * These counters can also help characterize which access methods + * are in use. DIRECT by itself shows whether there is any O_DIRECT + * traffic. NORMAL + DIRECT shows how much data is going through + * the system call interface. A large amount of SERVER traffic + * without much NORMAL or DIRECT traffic shows that applications + * are using mapped files. + * + * NFS page counters + * + * These count the number of pages read or written via nfs_readpage(), + * nfs_readpages(), or their write equivalents. + * + * NB: When adding new byte counters, please include the measured + * units in the name of each byte counter to help users of this + * interface determine what exactly is being counted. + */ +enum nfs_stat_bytecounters { + NFSIOS_NORMALREADBYTES = 0, + NFSIOS_NORMALWRITTENBYTES, + NFSIOS_DIRECTREADBYTES, + NFSIOS_DIRECTWRITTENBYTES, + NFSIOS_SERVERREADBYTES, + NFSIOS_SERVERWRITTENBYTES, + NFSIOS_READPAGES, + NFSIOS_WRITEPAGES, + __NFSIOS_BYTESMAX, +}; + +/* + * NFS event counters + * + * These counters provide a low-overhead way of monitoring client + * activity without enabling NFS trace debugging. The counters + * show the rate at which VFS requests are made, and how often the + * client invalidates its data and attribute caches. This allows + * system administrators to monitor such things as how close-to-open + * is working, and answer questions such as "why are there so many + * GETATTR requests on the wire?" + * + * They also count anamolous events such as short reads and writes, + * silly renames due to close-after-delete, and operations that + * change the size of a file (such operations can often be the + * source of data corruption if applications aren't using file + * locking properly). + */ +enum nfs_stat_eventcounters { + NFSIOS_INODEREVALIDATE = 0, + NFSIOS_DENTRYREVALIDATE, + NFSIOS_DATAINVALIDATE, + NFSIOS_ATTRINVALIDATE, + NFSIOS_VFSOPEN, + NFSIOS_VFSLOOKUP, + NFSIOS_VFSACCESS, + NFSIOS_VFSUPDATEPAGE, + NFSIOS_VFSREADPAGE, + NFSIOS_VFSREADPAGES, + NFSIOS_VFSWRITEPAGE, + NFSIOS_VFSWRITEPAGES, + NFSIOS_VFSGETDENTS, + NFSIOS_VFSSETATTR, + NFSIOS_VFSFLUSH, + NFSIOS_VFSFSYNC, + NFSIOS_VFSLOCK, + NFSIOS_VFSRELEASE, + NFSIOS_CONGESTIONWAIT, + NFSIOS_SETATTRTRUNC, + NFSIOS_EXTENDWRITE, + NFSIOS_SILLYRENAME, + NFSIOS_SHORTREAD, + NFSIOS_SHORTWRITE, + NFSIOS_DELAY, + __NFSIOS_COUNTSMAX, +}; + +#endif /* _LINUX_NFS_IOSTAT */ |