From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from aserp1040.oracle.com ([141.146.126.69]:45534 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752006Ab3BOR3U convert rfc822-to-8bit (ORCPT ); Fri, 15 Feb 2013 12:29:20 -0500 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 6.2 \(1499\)) Subject: Re: [PATCH v2 3/3] nfsd: add new reply_cache_stats file in nfsdfs From: Chuck Lever In-Reply-To: <1360948990-2265-4-git-send-email-jlayton@redhat.com> Date: Fri, 15 Feb 2013 12:29:08 -0500 Cc: bfields@fieldses.org, linux-nfs@vger.kernel.org Message-Id: References: <1360948990-2265-1-git-send-email-jlayton@redhat.com> <1360948990-2265-4-git-send-email-jlayton@redhat.com> To: Jeff Layton Sender: linux-nfs-owner@vger.kernel.org List-ID: On Feb 15, 2013, at 12:23 PM, Jeff Layton wrote: > For presenting statistics relating to duplicate reply cache. > > Signed-off-by: Jeff Layton > --- > fs/nfsd/cache.h | 1 + > fs/nfsd/nfscache.c | 37 +++++++++++++++++++++++++++++++++---- > fs/nfsd/nfsctl.c | 9 +++++++++ > 3 files changed, 43 insertions(+), 4 deletions(-) > > diff --git a/fs/nfsd/cache.h b/fs/nfsd/cache.h > index 87fd141..d5c5b3e 100644 > --- a/fs/nfsd/cache.h > +++ b/fs/nfsd/cache.h > @@ -82,6 +82,7 @@ int nfsd_reply_cache_init(void); > void nfsd_reply_cache_shutdown(void); > int nfsd_cache_lookup(struct svc_rqst *); > void nfsd_cache_update(struct svc_rqst *, int, __be32 *); > +int nfsd_reply_cache_stats_open(struct inode *, struct file *); > > #ifdef CONFIG_NFSD_V4 > void nfsd4_set_statp(struct svc_rqst *rqstp, __be32 *statp); > diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c > index ad1d069..b155afa 100644 > --- a/fs/nfsd/nfscache.c > +++ b/fs/nfsd/nfscache.c > @@ -23,12 +23,17 @@ > static struct hlist_head * cache_hash; > static struct list_head lru_head; > static struct kmem_cache *drc_slab; > -static unsigned int num_drc_entries; > -static unsigned int max_drc_entries; > -static unsigned int drc_mem_usage; > -static unsigned int csum_misses; > > /* > + * Stats on the duplicate reply cache code. All of these and the "rc" fields > + * in nfsdstats are protected by the cache_lock > + */ > +static unsigned int num_drc_entries; /* number of entries */ > +static unsigned int max_drc_entries; /* max number of entries */ > +static unsigned int drc_mem_usage; /* memory used by cache */ > +static unsigned int csum_misses; /* cache misses due only to > + csum comparison failures */ > +/* > * Calculate the hash index from an XID. > */ > static inline u32 request_hash(u32 xid) > @@ -545,3 +550,27 @@ nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *data) > vec->iov_len += data->iov_len; > return 1; > } > + > +/* > + * Note that fields may be added, removed or reordered in the future. Programs > + * scraping this file for info should test the labels to ensure they're > + * getting the correct field. > + */ > +static int nfsd_reply_cache_stats_show(struct seq_file *m, void *v) > +{ > + spin_lock(&cache_lock); > + seq_printf(m, "max entries: %u\n", max_drc_entries); > + seq_printf(m, "num entries: %u\n", num_drc_entries); > + seq_printf(m, "mem usage: %u\n", drc_mem_usage); > + seq_printf(m, "cache hits: %u\n", nfsdstats.rchits); > + seq_printf(m, "cache misses: %u\n", nfsdstats.rcmisses); > + seq_printf(m, "not cached: %u\n", nfsdstats.rcnocache); > + seq_printf(m, "checksum misses: %u\n", csum_misses); > + spin_unlock(&cache_lock); > + return 0; > +} Would it be hard to add a statistic that quantified the distribution of entries in the cache hash table? Something like "maximum length of cache hash chain" ? > + > +int nfsd_reply_cache_stats_open(struct inode *inode, struct file *file) > +{ > + return single_open(file, nfsd_reply_cache_stats_show, NULL); > +} > diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c > index 29c3f0d..5dea5af 100644 > --- a/fs/nfsd/nfsctl.c > +++ b/fs/nfsd/nfsctl.c > @@ -35,6 +35,7 @@ enum { > NFSD_Threads, > NFSD_Pool_Threads, > NFSD_Pool_Stats, > + NFSD_Reply_Cache_Stats, > NFSD_Versions, > NFSD_Ports, > NFSD_MaxBlkSize, > @@ -194,6 +195,13 @@ static const struct file_operations pool_stats_operations = { > .owner = THIS_MODULE, > }; > > +static struct file_operations reply_cache_stats_operations = { > + .open = nfsd_reply_cache_stats_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = single_release, > +}; > + > /*----------------------------------------------------------------------------*/ > /* > * payload - write methods > @@ -1024,6 +1032,7 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent) > [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_Reply_Cache_Stats] = {"reply_cache_stats", &reply_cache_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}, > -- > 1.7.11.7 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Chuck Lever chuck[dot]lever[at]oracle[dot]com