diff options
| author | NeilBrown <neilb@suse.de> | 2021-11-29 05:51:25 +0100 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2021-12-13 19:42:52 +0100 |
| commit | 2a36395fac3b72771f87c3ee4387e3a96d85a7cc (patch) | |
| tree | b2078229902140dbe1ffa20383eb730a5e7ddef0 /net | |
| parent | nfsd: make nfsd_stats.th_cnt atomic_t (diff) | |
| download | linux-2a36395fac3b72771f87c3ee4387e3a96d85a7cc.tar.xz linux-2a36395fac3b72771f87c3ee4387e3a96d85a7cc.zip | |
SUNRPC: use sv_lock to protect updates to sv_nrthreads.
Using sv_lock means we don't need to hold the service mutex over these
updates.
In particular, svc_exit_thread() no longer requires synchronisation, so
threads can exit asynchronously.
Note that we could use an atomic_t, but as there are many more read
sites than writes, that would add unnecessary noise to the code.
Some reads are already racy, and there is no need for them to not be.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sunrpc/svc.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index acddc6e12e9e..2b2042234e4b 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -523,7 +523,7 @@ EXPORT_SYMBOL_GPL(svc_shutdown_net); /* * Destroy an RPC service. Should be called with appropriate locking to - * protect the sv_nrthreads, sv_permsocks and sv_tempsocks. + * protect sv_permsocks and sv_tempsocks. */ void svc_destroy(struct kref *ref) @@ -639,7 +639,10 @@ svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node) return ERR_PTR(-ENOMEM); svc_get(serv); - serv->sv_nrthreads++; + spin_lock_bh(&serv->sv_lock); + serv->sv_nrthreads += 1; + spin_unlock_bh(&serv->sv_lock); + spin_lock_bh(&pool->sp_lock); pool->sp_nrthreads++; list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads); @@ -880,7 +883,9 @@ svc_exit_thread(struct svc_rqst *rqstp) list_del_rcu(&rqstp->rq_all); spin_unlock_bh(&pool->sp_lock); + spin_lock_bh(&serv->sv_lock); serv->sv_nrthreads -= 1; + spin_unlock_bh(&serv->sv_lock); svc_sock_update_bufs(serv); svc_rqst_free(rqstp); |