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authorTrond Myklebust <Trond.Myklebust@netapp.com>2005-10-20 14:22:41 -0700
committerTrond Myklebust <Trond.Myklebust@netapp.com>2005-10-20 14:22:41 -0700
commit4e51336a00bdcb42960acca52c23e90e9f4e6959 (patch)
tree87d619bcd796a0c272abe2499bcc56bc3eda30b4 /fs/nfs/nfs4state.c
parenta0857d03b21fa54653c9d2fe7a315381176015b4 (diff)
downloadlwn-4e51336a00bdcb42960acca52c23e90e9f4e6959.tar.gz
lwn-4e51336a00bdcb42960acca52c23e90e9f4e6959.zip
NFSv4: Final tweak to sequence id
Sacrifice queueing fairness for performance. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/nfs4state.c')
-rw-r--r--fs/nfs/nfs4state.c23
1 files changed, 13 insertions, 10 deletions
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;
}