Commit eed2965a authored by Greg Banks's avatar Greg Banks Committed by Linus Torvalds
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[PATCH] knfsd: allow admin to set nthreads per node



Add /proc/fs/nfsd/pool_threads which allows the sysadmin (or a userspace
daemon) to read and change the number of nfsd threads in each pool.  The
format is a list of space-separated integers, one per pool.
Signed-off-by: default avatarGreg Banks <gnb@melbourne.sgi.com>
Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent bfd24160
......@@ -54,6 +54,7 @@ enum {
NFSD_List,
NFSD_Fh,
NFSD_Threads,
NFSD_Pool_Threads,
NFSD_Versions,
NFSD_Ports,
/*
......@@ -78,6 +79,7 @@ static ssize_t write_getfd(struct file *file, char *buf, size_t size);
static ssize_t write_getfs(struct file *file, char *buf, size_t size);
static ssize_t write_filehandle(struct file *file, char *buf, size_t size);
static ssize_t write_threads(struct file *file, char *buf, size_t size);
static ssize_t write_pool_threads(struct file *file, char *buf, size_t size);
static ssize_t write_versions(struct file *file, char *buf, size_t size);
static ssize_t write_ports(struct file *file, char *buf, size_t size);
#ifdef CONFIG_NFSD_V4
......@@ -95,6 +97,7 @@ static ssize_t (*write_op[])(struct file *, char *, size_t) = {
[NFSD_Getfs] = write_getfs,
[NFSD_Fh] = write_filehandle,
[NFSD_Threads] = write_threads,
[NFSD_Pool_Threads] = write_pool_threads,
[NFSD_Versions] = write_versions,
[NFSD_Ports] = write_ports,
#ifdef CONFIG_NFSD_V4
......@@ -363,6 +366,72 @@ static ssize_t write_threads(struct file *file, char *buf, size_t size)
return strlen(buf);
}
extern int nfsd_nrpools(void);
extern int nfsd_get_nrthreads(int n, int *);
extern int nfsd_set_nrthreads(int n, int *);
static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
{
/* if size > 0, look for an array of number of threads per node
* and apply them then write out number of threads per node as reply
*/
char *mesg = buf;
int i;
int rv;
int len;
int npools = nfsd_nrpools();
int *nthreads;
if (npools == 0) {
/*
* NFS is shut down. The admin can start it by
* writing to the threads file but NOT the pool_threads
* file, sorry. Report zero threads.
*/
strcpy(buf, "0\n");
return strlen(buf);
}
nthreads = kcalloc(npools, sizeof(int), GFP_KERNEL);
if (nthreads == NULL)
return -ENOMEM;
if (size > 0) {
for (i = 0; i < npools; i++) {
rv = get_int(&mesg, &nthreads[i]);
if (rv == -ENOENT)
break; /* fewer numbers than pools */
if (rv)
goto out_free; /* syntax error */
rv = -EINVAL;
if (nthreads[i] < 0)
goto out_free;
}
rv = nfsd_set_nrthreads(i, nthreads);
if (rv)
goto out_free;
}
rv = nfsd_get_nrthreads(npools, nthreads);
if (rv)
goto out_free;
mesg = buf;
size = SIMPLE_TRANSACTION_LIMIT;
for (i = 0; i < npools && size > 0; i++) {
snprintf(mesg, size, "%d%c", nthreads[i], (i == npools-1 ? '\n' : ' '));
len = strlen(mesg);
size -= len;
mesg += len;
}
return (mesg-buf);
out_free:
kfree(nthreads);
return rv;
}
static ssize_t write_versions(struct file *file, char *buf, size_t size)
{
/*
......@@ -544,6 +613,7 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent)
[NFSD_List] = {"exports", &exports_operations, S_IRUGO},
[NFSD_Fh] = {"filehandle", &transaction_ops, S_IWUSR|S_IRUSR},
[NFSD_Threads] = {"threads", &transaction_ops, S_IWUSR|S_IRUSR},
[NFSD_Pool_Threads] = {"pool_threads", &transaction_ops, S_IWUSR|S_IRUSR},
[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
#ifdef CONFIG_NFSD_V4
......
......@@ -238,6 +238,80 @@ static int nfsd_init_socks(int port)
return 0;
}
int nfsd_nrpools(void)
{
if (nfsd_serv == NULL)
return 0;
else
return nfsd_serv->sv_nrpools;
}
int nfsd_get_nrthreads(int n, int *nthreads)
{
int i = 0;
if (nfsd_serv != NULL) {
for (i = 0; i < nfsd_serv->sv_nrpools && i < n; i++)
nthreads[i] = nfsd_serv->sv_pools[i].sp_nrthreads;
}
return 0;
}
int nfsd_set_nrthreads(int n, int *nthreads)
{
int i = 0;
int tot = 0;
int err = 0;
if (nfsd_serv == NULL || n <= 0)
return 0;
if (n > nfsd_serv->sv_nrpools)
n = nfsd_serv->sv_nrpools;
/* enforce a global maximum number of threads */
tot = 0;
for (i = 0; i < n; i++) {
if (nthreads[i] > NFSD_MAXSERVS)
nthreads[i] = NFSD_MAXSERVS;
tot += nthreads[i];
}
if (tot > NFSD_MAXSERVS) {
/* total too large: scale down requested numbers */
for (i = 0; i < n && tot > 0; i++) {
int new = nthreads[i] * NFSD_MAXSERVS / tot;
tot -= (nthreads[i] - new);
nthreads[i] = new;
}
for (i = 0; i < n && tot > 0; i++) {
nthreads[i]--;
tot--;
}
}
/*
* There must always be a thread in pool 0; the admin
* can't shut down NFS completely using pool_threads.
*/
if (nthreads[0] == 0)
nthreads[0] = 1;
/* apply the new numbers */
lock_kernel();
svc_get(nfsd_serv);
for (i = 0; i < n; i++) {
err = svc_set_num_threads(nfsd_serv, &nfsd_serv->sv_pools[i],
nthreads[i]);
if (err)
break;
}
svc_destroy(nfsd_serv);
unlock_kernel();
return err;
}
int
nfsd_svc(unsigned short port, int nrservs)
{
......
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