From 3c1c995cc2e49f6f7504586ad07c5d80c6aa3301 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 29 Jul 2014 21:34:39 -0400 Subject: [PATCH] nfsd: optimize destroy_lockowner cl_lock thrashing Reduce the cl_lock trashing in destroy_lockowner. Unhash all of the lockstateids on the lockowner's list. Put the reference under the lock and see if it was the last one. If so, then add it to a private list to be destroyed after we drop the lock. Signed-off-by: Jeff Layton Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 51 ++++++++++++++++++++++++++++++--------------- 1 file changed, 34 insertions(+), 17 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 9b342e164407..9358cbe2283d 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -983,14 +983,23 @@ static void nfs4_free_lock_stateid(struct nfs4_stid *stid) nfs4_free_ol_stateid(stid); } -static void release_lock_stateid(struct nfs4_ol_stateid *stp) +static void unhash_lock_stateid(struct nfs4_ol_stateid *stp) { struct nfs4_openowner *oo = openowner(stp->st_openstp->st_stateowner); - spin_lock(&oo->oo_owner.so_client->cl_lock); - list_del(&stp->st_locks); + lockdep_assert_held(&oo->oo_owner.so_client->cl_lock); + + list_del_init(&stp->st_locks); unhash_generic_stateid(stp); unhash_stid(&stp->st_stid); +} + +static void release_lock_stateid(struct nfs4_ol_stateid *stp) +{ + struct nfs4_openowner *oo = openowner(stp->st_openstp->st_stateowner); + + spin_lock(&oo->oo_owner.so_client->cl_lock); + unhash_lock_stateid(stp); spin_unlock(&oo->oo_owner.so_client->cl_lock); nfs4_put_stid(&stp->st_stid); } @@ -1004,30 +1013,38 @@ static void unhash_lockowner_locked(struct nfs4_lockowner *lo) list_del_init(&lo->lo_owner.so_strhash); } -static void release_lockowner_stateids(struct nfs4_lockowner *lo) +static void release_lockowner(struct nfs4_lockowner *lo) { struct nfs4_client *clp = lo->lo_owner.so_client; struct nfs4_ol_stateid *stp; + struct list_head reaplist; - lockdep_assert_held(&clp->cl_lock); + INIT_LIST_HEAD(&reaplist); + spin_lock(&clp->cl_lock); + unhash_lockowner_locked(lo); while (!list_empty(&lo->lo_owner.so_stateids)) { stp = list_first_entry(&lo->lo_owner.so_stateids, struct nfs4_ol_stateid, st_perstateowner); - spin_unlock(&clp->cl_lock); - release_lock_stateid(stp); - spin_lock(&clp->cl_lock); + unhash_lock_stateid(stp); + /* + * We now know that no new references can be added to the + * stateid. If ours is the last one, finish the unhashing + * and put it on the list to be reaped. + */ + if (atomic_dec_and_test(&stp->st_stid.sc_count)) { + idr_remove(&clp->cl_stateids, + stp->st_stid.sc_stateid.si_opaque.so_id); + list_add(&stp->st_locks, &reaplist); + } } -} - -static void release_lockowner(struct nfs4_lockowner *lo) -{ - struct nfs4_client *clp = lo->lo_owner.so_client; - - spin_lock(&clp->cl_lock); - unhash_lockowner_locked(lo); - release_lockowner_stateids(lo); spin_unlock(&clp->cl_lock); + while (!list_empty(&reaplist)) { + stp = list_first_entry(&reaplist, struct nfs4_ol_stateid, + st_locks); + list_del(&stp->st_locks); + stp->st_stid.sc_free(&stp->st_stid); + } nfs4_put_stateowner(&lo->lo_owner); } -- GitLab