diff options
| author | NeilBrown <neilb@suse.de> | 2021-11-29 15:51:25 +1100 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2021-12-13 13:42:51 -0500 |
| commit | 9b6c8c9bebccd5fb785c306b948c08874a88874d (patch) | |
| tree | 8998256835b130819b13a728f521e0b31b407f9d | |
| parent | ec52361df99b490f6af412b046df9799b92c1050 (diff) | |
nfsd: make nfsd_stats.th_cnt atomic_t
This allows us to move the updates for th_cnt out of the mutex.
This is a step towards reducing mutex coverage in nfsd().
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
| -rw-r--r-- | fs/nfsd/nfssvc.c | 6 | ||||
| -rw-r--r-- | fs/nfsd/stats.c | 2 | ||||
| -rw-r--r-- | fs/nfsd/stats.h | 4 |
3 files changed, 5 insertions, 7 deletions
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index 5f605e7e8091..fc5899502a83 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -57,7 +57,7 @@ static __be32 nfsd_init_request(struct svc_rqst *, /* * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and the members * of the svc_serv struct. In particular, ->sv_nrthreads but also to some - * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt + * extent ->sv_temp_socks and ->sv_permsocks. * * If (out side the lock) nn->nfsd_serv is non-NULL, then it must point to a * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0 (unless @@ -955,8 +955,8 @@ nfsd(void *vrqstp) allow_signal(SIGINT); allow_signal(SIGQUIT); - nfsdstats.th_cnt++; mutex_unlock(&nfsd_mutex); + atomic_inc(&nfsdstats.th_cnt); set_freezable(); @@ -983,8 +983,8 @@ nfsd(void *vrqstp) /* Clear signals before calling svc_exit_thread() */ flush_signals(current); + atomic_dec(&nfsdstats.th_cnt); mutex_lock(&nfsd_mutex); - nfsdstats.th_cnt --; out: /* Take an extra ref so that the svc_put in svc_exit_thread() diff --git a/fs/nfsd/stats.c b/fs/nfsd/stats.c index 1d3b881e7382..a8c5a02a84f0 100644 --- a/fs/nfsd/stats.c +++ b/fs/nfsd/stats.c @@ -45,7 +45,7 @@ static int nfsd_proc_show(struct seq_file *seq, void *v) percpu_counter_sum_positive(&nfsdstats.counter[NFSD_STATS_IO_WRITE])); /* thread usage: */ - seq_printf(seq, "th %u 0", nfsdstats.th_cnt); + seq_printf(seq, "th %u 0", atomic_read(&nfsdstats.th_cnt)); /* deprecated thread usage histogram stats */ for (i = 0; i < 10; i++) diff --git a/fs/nfsd/stats.h b/fs/nfsd/stats.h index 51ecda852e23..9b43dc3d9991 100644 --- a/fs/nfsd/stats.h +++ b/fs/nfsd/stats.h @@ -29,11 +29,9 @@ enum { struct nfsd_stats { struct percpu_counter counter[NFSD_STATS_COUNTERS_NUM]; - /* Protected by nfsd_mutex */ - unsigned int th_cnt; /* number of available threads */ + atomic_t th_cnt; /* number of available threads */ }; - extern struct nfsd_stats nfsdstats; extern struct svc_stat nfsd_svcstats; |