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: Greg Banks <gnb@xxxxxxx> Signed-off-by: Harshula Jayasuriya <harshula@xxxxxxx> --- fs/nfsd/nfsctl.c | 12 ++++ fs/nfsd/nfssvc.c | 7 ++ include/linux/sunrpc/svc.h | 11 +++ net/sunrpc/svc_xprt.c | 100 +++++++++++++++++++++++++++++++++- 4 files changed, 129 insertions(+), 1 deletion(-) Index: bfields/fs/nfsd/nfsctl.c =================================================================== --- bfields.orig/fs/nfsd/nfsctl.c +++ bfields/fs/nfsd/nfsctl.c @@ -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 expo .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_ [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}, Index: bfields/fs/nfsd/nfssvc.c =================================================================== --- bfields.orig/fs/nfsd/nfssvc.c +++ bfields/fs/nfsd/nfssvc.c @@ -546,3 +546,10 @@ nfsd_dispatch(struct svc_rqst *rqstp, __ 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); +} Index: bfields/include/linux/sunrpc/svc.h =================================================================== --- bfields.orig/include/linux/sunrpc/svc.h +++ bfields/include/linux/sunrpc/svc.h @@ -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(str 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, Index: bfields/net/sunrpc/svc_xprt.c =================================================================== --- bfields.orig/net/sunrpc/svc_xprt.c +++ bfields/net/sunrpc/svc_xprt.c @@ -318,6 +318,8 @@ void svc_xprt_enqueue(struct svc_xprt *x 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 *x 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 *x 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, lon 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, lon 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) { @@ -1103,3 +1111,93 @@ int svc_xprt_names(struct svc_serv *serv 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); + +/*----------------------------------------------------------------------------*/ -- -- Greg Banks, P.Engineer, SGI Australian Software Group. the brightly coloured sporks of revolution. I don't speak for SGI. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
