Commit 03cf6c9f authored by Greg Banks's avatar Greg Banks Committed by J. Bruce Fields
Browse files

knfsd: add file to export stats about nfsd pools 

Add /proc/fs/nfsd/pool_stats to export to userspace various
statistics about the operation of rpc server thread pools.

This patch is based on a forward-ported version of
knfsd-add-pool-thread-stats which has been shipping in the SGI
"Enhanced NFS" product since 2006 and which was previously
posted:

http://article.gmane.org/gmane.linux.nfs/10375



It has also been updated thus:

 * moved EXPORT_SYMBOL() to near the function it exports
 * made the new struct struct seq_operations const
 * used SEQ_START_TOKEN instead of ((void *)1)
 * merged fix from SGI PV 990526 "sunrpc: use dprintk instead of
   printk in svc_pool_stats_*()" by Harshula Jayasuriya.
 * merged fix from SGI PV 964001 "Crash reading pool_stats before
   nfsds are started".

Signed-off-by: default avatarGreg Banks <gnb@sgi.com>
Signed-off-by: default avatarHarshula Jayasuriya <harshula@sgi.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
parent 59a252ff

fs/nfsd/nfsctl.c

+12 −0
Original line number Diff line number Diff line
@@ -60,6 +60,7 @@ enum { 
	NFSD_FO_UnlockFS,

	NFSD_Threads,

	NFSD_Pool_Threads,

	NFSD_Pool_Stats,

	NFSD_Versions,

	NFSD_Ports,

	NFSD_MaxBlkSize,
@@ -172,6 +173,16 @@ static const struct file_operations exports_operations = { 
	.owner		= THIS_MODULE,

};



extern int nfsd_pool_stats_open(struct inode *inode, struct file *file);



static struct file_operations pool_stats_operations = {

	.open		= nfsd_pool_stats_open,

	.read		= seq_read,

	.llseek		= seq_lseek,

	.release	= seq_release,

	.owner		= THIS_MODULE,

};



/*----------------------------------------------------------------------------*/

/*

 * payload - write methods
@@ -1246,6 +1257,7 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent) 
		[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_Pool_Stats] = {"pool_stats", &pool_stats_operations, S_IRUGO},

		[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},

		[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},

		[NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},

fs/nfsd/nfssvc.c

+7 −0
Original line number Diff line number Diff line
@@ -546,3 +546,10 @@ nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp) 
	nfsd_cache_update(rqstp, proc->pc_cachetype, statp + 1);

	return 1;

}



int nfsd_pool_stats_open(struct inode *inode, struct file *file)

{

	if (nfsd_serv == NULL)

		return -ENODEV;

	return svc_pool_stats_open(nfsd_serv, file);

}

include/linux/sunrpc/svc.h

+11 −0
Original line number Diff line number Diff line
@@ -24,6 +24,15 @@ 
 */

typedef int		(*svc_thread_fn)(void *);



/* statistics for svc_pool structures */

struct svc_pool_stats {

	unsigned long	packets;

	unsigned long	sockets_queued;

	unsigned long	threads_woken;

	unsigned long	overloads_avoided;

	unsigned long	threads_timedout;

};



/*

 *

 * RPC service thread pool.
@@ -42,6 +51,7 @@ struct svc_pool { 
	unsigned int		sp_nrthreads;	/* # of threads in pool */

	struct list_head	sp_all_threads;	/* all server threads */

	int			sp_nwaking;	/* number of threads woken but not yet active */

	struct svc_pool_stats	sp_stats;	/* statistics on pool operation */

} ____cacheline_aligned_in_smp;



/*
@@ -396,6 +406,7 @@ struct svc_serv * svc_create_pooled(struct svc_program *, unsigned int, 
			sa_family_t, void (*shutdown)(struct svc_serv *),

			svc_thread_fn, struct module *);

int		   svc_set_num_threads(struct svc_serv *, struct svc_pool *, int);

int		   svc_pool_stats_open(struct svc_serv *serv, struct file *file);

void		   svc_destroy(struct svc_serv *);

int		   svc_process(struct svc_rqst *);

int		   svc_register(const struct svc_serv *, const unsigned short,

net/sunrpc/svc_xprt.c

+99 −1
Original line number Diff line number Diff line
@@ -318,6 +318,8 @@ void svc_xprt_enqueue(struct svc_xprt *xprt) 
		goto out_unlock;

	}



	pool->sp_stats.packets++;



	/* Mark transport as busy. It will remain in this state until

	 * the provider calls svc_xprt_received. We update XPT_BUSY

	 * atomically because it also guards against trying to enqueue
@@ -355,6 +357,7 @@ void svc_xprt_enqueue(struct svc_xprt *xprt) 
	if (pool->sp_nwaking >= SVC_MAX_WAKING) {

		/* too many threads are runnable and trying to wake up */

		thread_avail = 0;

		pool->sp_stats.overloads_avoided++;

	}



	if (thread_avail) {
@@ -374,11 +377,13 @@ void svc_xprt_enqueue(struct svc_xprt *xprt) 
		atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);

		rqstp->rq_waking = 1;

		pool->sp_nwaking++;

		pool->sp_stats.threads_woken++;

		BUG_ON(xprt->xpt_pool != pool);

		wake_up(&rqstp->rq_wait);

	} else {

		dprintk("svc: transport %p put into queue\n", xprt);

		list_add_tail(&xprt->xpt_ready, &pool->sp_sockets);

		pool->sp_stats.sockets_queued++;

		BUG_ON(xprt->xpt_pool != pool);

	}
@@ -591,6 +596,7 @@ int svc_recv(struct svc_rqst *rqstp, long timeout) 
	int			pages;

	struct xdr_buf		*arg;

	DECLARE_WAITQUEUE(wait, current);

	long			time_left;



	dprintk("svc: server %p waiting for data (to = %ld)\n",

		rqstp, timeout);
@@ -676,12 +682,14 @@ int svc_recv(struct svc_rqst *rqstp, long timeout) 
		add_wait_queue(&rqstp->rq_wait, &wait);

		spin_unlock_bh(&pool->sp_lock);



		schedule_timeout(timeout);

		time_left = schedule_timeout(timeout);



		try_to_freeze();



		spin_lock_bh(&pool->sp_lock);

		remove_wait_queue(&rqstp->rq_wait, &wait);

		if (!time_left)

			pool->sp_stats.threads_timedout++;



		xprt = rqstp->rq_xprt;

		if (!xprt) {
@@ -1114,3 +1122,93 @@ int svc_xprt_names(struct svc_serv *serv, char *buf, int buflen) 
	return totlen;

}

EXPORT_SYMBOL_GPL(svc_xprt_names);





/*----------------------------------------------------------------------------*/



static void *svc_pool_stats_start(struct seq_file *m, loff_t *pos)

{

	unsigned int pidx = (unsigned int)*pos;

	struct svc_serv *serv = m->private;



	dprintk("svc_pool_stats_start, *pidx=%u\n", pidx);



	lock_kernel();

	/* bump up the pseudo refcount while traversing */

	svc_get(serv);

	unlock_kernel();



	if (!pidx)

		return SEQ_START_TOKEN;

	return (pidx > serv->sv_nrpools ? NULL : &serv->sv_pools[pidx-1]);

}



static void *svc_pool_stats_next(struct seq_file *m, void *p, loff_t *pos)

{

	struct svc_pool *pool = p;

	struct svc_serv *serv = m->private;



	dprintk("svc_pool_stats_next, *pos=%llu\n", *pos);



	if (p == SEQ_START_TOKEN) {

		pool = &serv->sv_pools[0];

	} else {

		unsigned int pidx = (pool - &serv->sv_pools[0]);

		if (pidx < serv->sv_nrpools-1)

			pool = &serv->sv_pools[pidx+1];

		else

			pool = NULL;

	}

	++*pos;

	return pool;

}



static void svc_pool_stats_stop(struct seq_file *m, void *p)

{

	struct svc_serv *serv = m->private;



	lock_kernel();

	/* this function really, really should have been called svc_put() */

	svc_destroy(serv);

	unlock_kernel();

}



static int svc_pool_stats_show(struct seq_file *m, void *p)

{

	struct svc_pool *pool = p;



	if (p == SEQ_START_TOKEN) {

		seq_puts(m, "# pool packets-arrived sockets-enqueued threads-woken overloads-avoided threads-timedout\n");

		return 0;

	}



	seq_printf(m, "%u %lu %lu %lu %lu %lu\n",

		pool->sp_id,

		pool->sp_stats.packets,

		pool->sp_stats.sockets_queued,

		pool->sp_stats.threads_woken,

		pool->sp_stats.overloads_avoided,

		pool->sp_stats.threads_timedout);



	return 0;

}



static const struct seq_operations svc_pool_stats_seq_ops = {

	.start	= svc_pool_stats_start,

	.next	= svc_pool_stats_next,

	.stop	= svc_pool_stats_stop,

	.show	= svc_pool_stats_show,

};



int svc_pool_stats_open(struct svc_serv *serv, struct file *file)

{

	int err;



	err = seq_open(file, &svc_pool_stats_seq_ops);

	if (!err)

		((struct seq_file *) file->private_data)->private = serv;

	return err;

}

EXPORT_SYMBOL(svc_pool_stats_open);



/*----------------------------------------------------------------------------*/

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