NFS: introduce mechanism for tracking NFS client metrics

Add a per-superblock performance counter facility to the NFS client.  This
facility mimics the counters available for block devices and for
networking.  Expose these new counters via the new /proc/self/mountstats
interface.

Thanks to Andrew Morton and Trond Myklebust for their review and comments.

Test plan:
fsx and iozone on UP and SMP systems, with and without pre-emption.  Watch
for memory overwrite bugs, and performance loss (significantly more CPU
required per op).

Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever 2006-03-20 13:44:13 -05:00 committed by Trond Myklebust
parent c8bded96aa
commit d9ef5a8c26
3 changed files with 252 additions and 6 deletions

View File

@ -42,6 +42,7 @@
#include "nfs4_fs.h"
#include "callback.h"
#include "delegation.h"
#include "iostat.h"
#define NFSDBG_FACILITY NFSDBG_VFS
#define NFS_PARANOIA 1
@ -65,6 +66,7 @@ static void nfs_clear_inode(struct inode *);
static void nfs_umount_begin(struct super_block *);
static int nfs_statfs(struct super_block *, struct kstatfs *);
static int nfs_show_options(struct seq_file *, struct vfsmount *);
static int nfs_show_stats(struct seq_file *, struct vfsmount *);
static void nfs_zap_acl_cache(struct inode *);
static struct rpc_program nfs_program;
@ -78,6 +80,7 @@ static struct super_operations nfs_sops = {
.clear_inode = nfs_clear_inode,
.umount_begin = nfs_umount_begin,
.show_options = nfs_show_options,
.show_stats = nfs_show_stats,
};
/*
@ -290,6 +293,12 @@ nfs_sb_init(struct super_block *sb, rpc_authflavor_t authflavor)
}
sb->s_root->d_op = server->rpc_ops->dentry_ops;
server->io_stats = nfs_alloc_iostats();
if (!server->io_stats) {
no_root_error = -ENOMEM;
goto out_no_root;
}
/* Get some general file system info */
if (server->namelen == 0 &&
server->rpc_ops->pathconf(server, &server->fh, &pathinfo) >= 0)
@ -582,7 +591,7 @@ nfs_statfs(struct super_block *sb, struct kstatfs *buf)
}
static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss, int showdefaults)
{
static struct proc_nfs_info {
int flag;
@ -598,20 +607,19 @@ static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
{ 0, NULL, NULL }
};
struct proc_nfs_info *nfs_infop;
struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
char buf[12];
char *proto;
seq_printf(m, ",vers=%d", nfss->rpc_ops->version);
seq_printf(m, ",rsize=%d", nfss->rsize);
seq_printf(m, ",wsize=%d", nfss->wsize);
if (nfss->acregmin != 3*HZ)
if (nfss->acregmin != 3*HZ || showdefaults)
seq_printf(m, ",acregmin=%d", nfss->acregmin/HZ);
if (nfss->acregmax != 60*HZ)
if (nfss->acregmax != 60*HZ || showdefaults)
seq_printf(m, ",acregmax=%d", nfss->acregmax/HZ);
if (nfss->acdirmin != 30*HZ)
if (nfss->acdirmin != 30*HZ || showdefaults)
seq_printf(m, ",acdirmin=%d", nfss->acdirmin/HZ);
if (nfss->acdirmax != 60*HZ)
if (nfss->acdirmax != 60*HZ || showdefaults)
seq_printf(m, ",acdirmax=%d", nfss->acdirmax/HZ);
for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
if (nfss->flags & nfs_infop->flag)
@ -633,8 +641,89 @@ static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
seq_printf(m, ",proto=%s", proto);
seq_printf(m, ",timeo=%lu", 10U * nfss->retrans_timeo / HZ);
seq_printf(m, ",retrans=%u", nfss->retrans_count);
}
static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
{
struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
nfs_show_mount_options(m, nfss, 0);
seq_puts(m, ",addr=");
seq_escape(m, nfss->hostname, " \t\n\\");
return 0;
}
static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
{
int i, cpu;
struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
struct rpc_auth *auth = nfss->client->cl_auth;
struct nfs_iostats totals = { };
seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
/*
* Display all mount option settings
*/
seq_printf(m, "\n\topts:\t");
seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
nfs_show_mount_options(m, nfss, 1);
seq_printf(m, "\n\tcaps:\t");
seq_printf(m, "caps=0x%x", nfss->caps);
seq_printf(m, ",wtmult=%d", nfss->wtmult);
seq_printf(m, ",dtsize=%d", nfss->dtsize);
seq_printf(m, ",bsize=%d", nfss->bsize);
seq_printf(m, ",namelen=%d", nfss->namelen);
#ifdef CONFIG_NFS_V4
if (nfss->rpc_ops->version == 4) {
seq_printf(m, "\n\tnfsv4:\t");
seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
}
#endif
/*
* Display security flavor in effect for this mount
*/
seq_printf(m, "\n\tsec:\tflavor=%d", auth->au_ops->au_flavor);
if (auth->au_flavor)
seq_printf(m, ",pseudoflavor=%d", auth->au_flavor);
/*
* Display superblock I/O counters
*/
for (cpu = 0; cpu < NR_CPUS; cpu++) {
struct nfs_iostats *stats;
if (!cpu_possible(cpu))
continue;
preempt_disable();
stats = per_cpu_ptr(nfss->io_stats, cpu);
for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
totals.events[i] += stats->events[i];
for (i = 0; i < __NFSIOS_BYTESMAX; i++)
totals.bytes[i] += stats->bytes[i];
preempt_enable();
}
seq_printf(m, "\n\tevents:\t");
for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
seq_printf(m, "%lu ", totals.events[i]);
seq_printf(m, "\n\tbytes:\t");
for (i = 0; i < __NFSIOS_BYTESMAX; i++)
seq_printf(m, "%Lu ", totals.bytes[i]);
return 0;
}
@ -1742,6 +1831,7 @@ static struct super_operations nfs4_sops = {
.clear_inode = nfs4_clear_inode,
.umount_begin = nfs_umount_begin,
.show_options = nfs_show_options,
.show_stats = nfs_show_stats,
};
/*
@ -2015,6 +2105,7 @@ out_err:
out_free:
kfree(server->mnt_path);
kfree(server->hostname);
nfs_free_iostats(server->io_stats);
kfree(server);
return s;
}

152
fs/nfs/iostat.h Normal file
View File

@ -0,0 +1,152 @@
/*
* linux/fs/nfs/iostat.h
*
* Declarations for NFS client per-mount 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 _NFS_IOSTAT
#define _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.
*/
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_COUNTSMAX,
};
#ifdef __KERNEL__
#include <linux/percpu.h>
#include <linux/cache.h>
struct nfs_iostats {
unsigned long long bytes[__NFSIOS_BYTESMAX];
unsigned long events[__NFSIOS_COUNTSMAX];
} ____cacheline_aligned;
static inline void nfs_inc_stats(struct inode *inode, enum nfs_stat_eventcounters stat)
{
struct nfs_iostats *iostats;
int cpu;
cpu = get_cpu();
iostats = per_cpu_ptr(NFS_SERVER(inode)->io_stats, cpu);
iostats->events[stat] ++;
put_cpu_no_resched();
}
static inline void nfs_add_stats(struct inode *inode, enum nfs_stat_bytecounters stat, unsigned long addend)
{
struct nfs_iostats *iostats;
int cpu;
cpu = get_cpu();
iostats = per_cpu_ptr(NFS_SERVER(inode)->io_stats, cpu);
iostats->bytes[stat] += addend;
put_cpu_no_resched();
}
static inline struct nfs_iostats *nfs_alloc_iostats(void)
{
return alloc_percpu(struct nfs_iostats);
}
static inline void nfs_free_iostats(struct nfs_iostats *stats)
{
free_percpu(stats);
}
#endif
#endif

View File

@ -4,6 +4,8 @@
#include <linux/list.h>
#include <linux/backing-dev.h>
struct nfs_iostats;
/*
* NFS client parameters stored in the superblock.
*/
@ -12,6 +14,7 @@ struct nfs_server {
struct rpc_clnt * client_sys; /* 2nd handle for FSINFO */
struct rpc_clnt * client_acl; /* ACL RPC client handle */
struct nfs_rpc_ops * rpc_ops; /* NFS protocol vector */
struct nfs_iostats * io_stats; /* I/O statistics */
struct backing_dev_info backing_dev_info;
int flags; /* various flags */
unsigned int caps; /* server capabilities */