From 4e51336a00bdcb42960acca52c23e90e9f4e6959 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 20 Oct 2005 14:22:41 -0700 Subject: [PATCH] NFSv4: Final tweak to sequence id Sacrifice queueing fairness for performance. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4_fs.h | 2 +- fs/nfs/nfs4state.c | 23 +++++++++++++---------- 2 files changed, 14 insertions(+), 11 deletions(-) diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 45bff1d1a513..5c0dd26d0985 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -110,8 +110,8 @@ struct nfs_seqid_counter { }; struct nfs_seqid { - struct list_head list; struct nfs_seqid_counter *sequence; + struct list_head list; }; static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status) diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index da0861db57fb..c59ef90e956b 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -670,15 +670,12 @@ void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t f struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter) { - struct rpc_sequence *sequence = counter->sequence; struct nfs_seqid *new; new = kmalloc(sizeof(*new), GFP_KERNEL); if (new != NULL) { new->sequence = counter; - spin_lock(&sequence->lock); - list_add_tail(&new->list, &sequence->list); - spin_unlock(&sequence->lock); + INIT_LIST_HEAD(&new->list); } return new; } @@ -687,10 +684,12 @@ void nfs_free_seqid(struct nfs_seqid *seqid) { struct rpc_sequence *sequence = seqid->sequence->sequence; - spin_lock(&sequence->lock); - list_del(&seqid->list); - rpc_wake_up(&sequence->wait); - spin_unlock(&sequence->lock); + if (!list_empty(&seqid->list)) { + spin_lock(&sequence->lock); + list_del(&seqid->list); + spin_unlock(&sequence->lock); + } + rpc_wake_up_next(&sequence->wait); kfree(seqid); } @@ -746,12 +745,16 @@ int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task) struct rpc_sequence *sequence = seqid->sequence->sequence; int status = 0; + if (sequence->list.next == &seqid->list) + goto out; spin_lock(&sequence->lock); - if (sequence->list.next != &seqid->list) { + if (!list_empty(&sequence->list)) { rpc_sleep_on(&sequence->wait, task, NULL, NULL); status = -EAGAIN; - } + } else + list_add(&seqid->list, &sequence->list); spin_unlock(&sequence->lock); +out: return status; }