ocfs2: calculate lockid hash values outside of the spinlock
Fixes a performance bug - pointed out by Andrew.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index 1c05d48..3b67536 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -39,6 +39,9 @@
#define DLM_HASH_BUCKETS (PAGE_SIZE / sizeof(struct hlist_head))
+/* Intended to make it easier for us to switch out hash functions */
+#define dlm_lockid_hash(_n, _l) full_name_hash(_n, _l)
+
enum dlm_ast_type {
DLM_AST = 0,
DLM_BAST,
@@ -694,7 +697,8 @@
struct dlm_lock_resource *res);
struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
const char *name,
- unsigned int len);
+ unsigned int len,
+ unsigned int hash);
struct dlm_lock_resource * dlm_lookup_lockres(struct dlm_ctxt *dlm,
const char *name,
unsigned int len);
diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index 8f3a9e3..a818fde 100644
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -90,7 +90,6 @@
assert_spin_locked(&dlm->spinlock);
q = &res->lockname;
- q->hash = full_name_hash(q->name, q->len);
bucket = &(dlm->lockres_hash[q->hash % DLM_HASH_BUCKETS]);
/* get a reference for our hashtable */
@@ -100,10 +99,10 @@
}
struct dlm_lock_resource * __dlm_lookup_lockres(struct dlm_ctxt *dlm,
- const char *name,
- unsigned int len)
+ const char *name,
+ unsigned int len,
+ unsigned int hash)
{
- unsigned int hash;
struct hlist_node *iter;
struct dlm_lock_resource *tmpres=NULL;
struct hlist_head *bucket;
@@ -112,8 +111,6 @@
assert_spin_locked(&dlm->spinlock);
- hash = full_name_hash(name, len);
-
bucket = &(dlm->lockres_hash[hash % DLM_HASH_BUCKETS]);
/* check for pre-existing lock */
@@ -135,9 +132,10 @@
unsigned int len)
{
struct dlm_lock_resource *res;
+ unsigned int hash = dlm_lockid_hash(name, len);
spin_lock(&dlm->spinlock);
- res = __dlm_lookup_lockres(dlm, name, len);
+ res = __dlm_lookup_lockres(dlm, name, len, hash);
spin_unlock(&dlm->spinlock);
return res;
}
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 940be4c..953aa84 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -603,7 +603,7 @@
memcpy(qname, name, namelen);
res->lockname.len = namelen;
- res->lockname.hash = full_name_hash(name, namelen);
+ res->lockname.hash = dlm_lockid_hash(name, namelen);
init_waitqueue_head(&res->wq);
spin_lock_init(&res->spinlock);
@@ -677,19 +677,20 @@
int blocked = 0;
int ret, nodenum;
struct dlm_node_iter iter;
- unsigned int namelen;
+ unsigned int namelen, hash;
int tries = 0;
int bit, wait_on_recovery = 0;
BUG_ON(!lockid);
namelen = strlen(lockid);
+ hash = dlm_lockid_hash(lockid, namelen);
mlog(0, "get lockres %s (len %d)\n", lockid, namelen);
lookup:
spin_lock(&dlm->spinlock);
- tmpres = __dlm_lookup_lockres(dlm, lockid, namelen);
+ tmpres = __dlm_lookup_lockres(dlm, lockid, namelen, hash);
if (tmpres) {
spin_unlock(&dlm->spinlock);
mlog(0, "found in hash!\n");
@@ -1316,7 +1317,7 @@
struct dlm_master_request *request = (struct dlm_master_request *) msg->buf;
struct dlm_master_list_entry *mle = NULL, *tmpmle = NULL;
char *name;
- unsigned int namelen;
+ unsigned int namelen, hash;
int found, ret;
int set_maybe;
int dispatch_assert = 0;
@@ -1331,6 +1332,7 @@
name = request->name;
namelen = request->namelen;
+ hash = dlm_lockid_hash(name, namelen);
if (namelen > DLM_LOCKID_NAME_MAX) {
response = DLM_IVBUFLEN;
@@ -1339,7 +1341,7 @@
way_up_top:
spin_lock(&dlm->spinlock);
- res = __dlm_lookup_lockres(dlm, name, namelen);
+ res = __dlm_lookup_lockres(dlm, name, namelen, hash);
if (res) {
spin_unlock(&dlm->spinlock);
@@ -1612,7 +1614,7 @@
struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf;
struct dlm_lock_resource *res = NULL;
char *name;
- unsigned int namelen;
+ unsigned int namelen, hash;
u32 flags;
int master_request = 0;
int ret = 0;
@@ -1622,6 +1624,7 @@
name = assert->name;
namelen = assert->namelen;
+ hash = dlm_lockid_hash(name, namelen);
flags = be32_to_cpu(assert->flags);
if (namelen > DLM_LOCKID_NAME_MAX) {
@@ -1670,7 +1673,7 @@
/* ok everything checks out with the MLE
* now check to see if there is a lockres */
- res = __dlm_lookup_lockres(dlm, name, namelen);
+ res = __dlm_lookup_lockres(dlm, name, namelen, hash);
if (res) {
spin_lock(&res->spinlock);
if (res->state & DLM_LOCK_RES_RECOVERING) {
@@ -2462,7 +2465,7 @@
struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf;
struct dlm_master_list_entry *mle = NULL, *oldmle = NULL;
const char *name;
- unsigned int namelen;
+ unsigned int namelen, hash;
int ret = 0;
if (!dlm_grab(dlm))
@@ -2470,6 +2473,7 @@
name = migrate->name;
namelen = migrate->namelen;
+ hash = dlm_lockid_hash(name, namelen);
/* preallocate.. if this fails, abort */
mle = (struct dlm_master_list_entry *) kmem_cache_alloc(dlm_mle_cache,
@@ -2482,7 +2486,7 @@
/* check for pre-existing lock */
spin_lock(&dlm->spinlock);
- res = __dlm_lookup_lockres(dlm, name, namelen);
+ res = __dlm_lookup_lockres(dlm, name, namelen, hash);
spin_lock(&dlm->master_lock);
if (res) {
@@ -2601,6 +2605,7 @@
struct list_head *iter, *iter2;
struct dlm_master_list_entry *mle;
struct dlm_lock_resource *res;
+ unsigned int hash;
mlog_entry("dlm=%s, dead node=%u\n", dlm->name, dead_node);
top:
@@ -2684,8 +2689,9 @@
mle->master, mle->new_master);
/* if there is a lockres associated with this
* mle, find it and set its owner to UNKNOWN */
+ hash = dlm_lockid_hash(mle->u.name.name, mle->u.name.len);
res = __dlm_lookup_lockres(dlm, mle->u.name.name,
- mle->u.name.len);
+ mle->u.name.len, hash);
if (res) {
/* unfortunately if we hit this rare case, our
* lock ordering is messed. we need to drop
diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
index 9962190..4f3d482 100644
--- a/fs/ocfs2/dlm/dlmrecovery.c
+++ b/fs/ocfs2/dlm/dlmrecovery.c
@@ -1404,6 +1404,7 @@
struct dlm_ctxt *dlm = data;
struct dlm_master_requery *req = (struct dlm_master_requery *)msg->buf;
struct dlm_lock_resource *res = NULL;
+ unsigned int hash;
int master = DLM_LOCK_RES_OWNER_UNKNOWN;
u32 flags = DLM_ASSERT_MASTER_REQUERY;
@@ -1413,8 +1414,10 @@
return master;
}
+ hash = dlm_lockid_hash(req->name, req->namelen);
+
spin_lock(&dlm->spinlock);
- res = __dlm_lookup_lockres(dlm, req->name, req->namelen);
+ res = __dlm_lookup_lockres(dlm, req->name, req->namelen, hash);
if (res) {
spin_lock(&res->spinlock);
master = res->owner;