[PATCH] quota: optimize i_dquot access
From: Konstantin Khlebnikov
Date: Thu Feb 12 2015 - 04:36:49 EST
Remove redundant calls of i_dquot(), keep pointer in local variable.
add/remove: 0/0 grow/shrink: 3/7 up/down: 40/-278 (-238)
function old new delta
__dquot_free_space 734 750 +16
__dquot_alloc_space 484 500 +16
dquot_free_inode 324 332 +8
dquot_drop 82 69 -13
vfs_load_quota_inode 1357 1341 -16
dquot_reclaim_space_nodirty 348 316 -32
dquot_disable 1980 1944 -36
dquot_claim_space_nodirty 354 314 -40
__dquot_drop 125 83 -42
__dquot_initialize 522 423 -99
Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
---
fs/quota/dquot.c | 63 +++++++++++++++++++++++++++++++++---------------------
1 file changed, 39 insertions(+), 24 deletions(-)
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 0ccd4ba..2112ed3 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -900,14 +900,17 @@ static inline struct dquot **i_dquot(struct inode *inode)
static int dqinit_needed(struct inode *inode, int type)
{
+ struct dquot * const *dquots;
int cnt;
if (IS_NOQUOTA(inode))
return 0;
+
+ dquots = i_dquot(inode);
if (type != -1)
- return !i_dquot(inode)[type];
+ return !dquots[type];
for (cnt = 0; cnt < MAXQUOTAS; cnt++)
- if (!i_dquot(inode)[cnt])
+ if (!dquots[cnt])
return 1;
return 0;
}
@@ -970,12 +973,13 @@ static void add_dquot_ref(struct super_block *sb, int type)
static void remove_inode_dquot_ref(struct inode *inode, int type,
struct list_head *tofree_head)
{
- struct dquot *dquot = i_dquot(inode)[type];
+ struct dquot **dquots = i_dquot(inode);
+ struct dquot *dquot = dquots[type];
- i_dquot(inode)[type] = NULL;
if (!dquot)
return;
+ dquots[type] = NULL;
if (list_empty(&dquot->dq_free)) {
/*
* The inode still has reference to dquot so it can't be in the
@@ -1389,13 +1393,15 @@ static int dquot_active(const struct inode *inode)
static void __dquot_initialize(struct inode *inode, int type)
{
int cnt, init_needed = 0;
- struct dquot *got[MAXQUOTAS];
+ struct dquot **dquots, *got[MAXQUOTAS];
struct super_block *sb = inode->i_sb;
qsize_t rsv;
if (!dquot_active(inode))
return;
+ dquots = i_dquot(inode);
+
/* First get references to structures we might need. */
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
struct kqid qid;
@@ -1407,7 +1413,7 @@ static void __dquot_initialize(struct inode *inode, int type)
* we check it without locking here to avoid unnecessary
* dqget()/dqput() calls.
*/
- if (i_dquot(inode)[cnt])
+ if (dquots[cnt])
continue;
init_needed = 1;
@@ -1438,8 +1444,8 @@ static void __dquot_initialize(struct inode *inode, int type)
/* We could race with quotaon or dqget() could have failed */
if (!got[cnt])
continue;
- if (!i_dquot(inode)[cnt]) {
- i_dquot(inode)[cnt] = got[cnt];
+ if (!dquots[cnt]) {
+ dquots[cnt] = got[cnt];
got[cnt] = NULL;
/*
* Make quota reservation system happy if someone
@@ -1447,7 +1453,7 @@ static void __dquot_initialize(struct inode *inode, int type)
*/
rsv = inode_get_rsv_space(inode);
if (unlikely(rsv))
- dquot_resv_space(i_dquot(inode)[cnt], rsv);
+ dquot_resv_space(dquots[cnt], rsv);
}
}
out_err:
@@ -1473,12 +1479,13 @@ EXPORT_SYMBOL(dquot_initialize);
static void __dquot_drop(struct inode *inode)
{
int cnt;
+ struct dquot **dquots = i_dquot(inode);
struct dquot *put[MAXQUOTAS];
spin_lock(&dq_data_lock);
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
- put[cnt] = i_dquot(inode)[cnt];
- i_dquot(inode)[cnt] = NULL;
+ put[cnt] = dquots[cnt];
+ dquots[cnt] = NULL;
}
spin_unlock(&dq_data_lock);
dqput_all(put);
@@ -1486,6 +1493,7 @@ static void __dquot_drop(struct inode *inode)
void dquot_drop(struct inode *inode)
{
+ struct dquot * const *dquots;
int cnt;
if (IS_NOQUOTA(inode))
@@ -1498,8 +1506,9 @@ void dquot_drop(struct inode *inode)
* must assure that nobody can come after the DQUOT_DROP and
* add quota pointers back anyway.
*/
+ dquots = i_dquot(inode);
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
- if (i_dquot(inode)[cnt])
+ if (dquots[cnt])
break;
}
@@ -1600,8 +1609,8 @@ int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags)
{
int cnt, ret = 0, index;
struct dquot_warn warn[MAXQUOTAS];
- struct dquot **dquots = i_dquot(inode);
int reserve = flags & DQUOT_SPACE_RESERVE;
+ struct dquot **dquots;
if (!dquot_active(inode)) {
inode_incr_space(inode, number, reserve);
@@ -1611,6 +1620,7 @@ int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags)
for (cnt = 0; cnt < MAXQUOTAS; cnt++)
warn[cnt].w_type = QUOTA_NL_NOWARN;
+ dquots = i_dquot(inode);
index = srcu_read_lock(&dquot_srcu);
spin_lock(&dq_data_lock);
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
@@ -1652,13 +1662,14 @@ int dquot_alloc_inode(struct inode *inode)
{
int cnt, ret = 0, index;
struct dquot_warn warn[MAXQUOTAS];
- struct dquot * const *dquots = i_dquot(inode);
+ struct dquot * const *dquots;
if (!dquot_active(inode))
return 0;
for (cnt = 0; cnt < MAXQUOTAS; cnt++)
warn[cnt].w_type = QUOTA_NL_NOWARN;
+ dquots = i_dquot(inode);
index = srcu_read_lock(&dquot_srcu);
spin_lock(&dq_data_lock);
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
@@ -1690,6 +1701,7 @@ EXPORT_SYMBOL(dquot_alloc_inode);
*/
int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
{
+ struct dquot **dquots;
int cnt, index;
if (!dquot_active(inode)) {
@@ -1697,18 +1709,18 @@ int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
return 0;
}
+ dquots = i_dquot(inode);
index = srcu_read_lock(&dquot_srcu);
spin_lock(&dq_data_lock);
/* Claim reserved quotas to allocated quotas */
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
- if (i_dquot(inode)[cnt])
- dquot_claim_reserved_space(i_dquot(inode)[cnt],
- number);
+ if (dquots[cnt])
+ dquot_claim_reserved_space(dquots[cnt], number);
}
/* Update inode bytes */
inode_claim_rsv_space(inode, number);
spin_unlock(&dq_data_lock);
- mark_all_dquot_dirty(i_dquot(inode));
+ mark_all_dquot_dirty(dquots);
srcu_read_unlock(&dquot_srcu, index);
return 0;
}
@@ -1719,6 +1731,7 @@ EXPORT_SYMBOL(dquot_claim_space_nodirty);
*/
void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number)
{
+ struct dquot **dquots;
int cnt, index;
if (!dquot_active(inode)) {
@@ -1726,18 +1739,18 @@ void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number)
return;
}
+ dquots = i_dquot(inode);
index = srcu_read_lock(&dquot_srcu);
spin_lock(&dq_data_lock);
/* Claim reserved quotas to allocated quotas */
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
- if (i_dquot(inode)[cnt])
- dquot_reclaim_reserved_space(i_dquot(inode)[cnt],
- number);
+ if (dquots[cnt])
+ dquot_reclaim_reserved_space(dquots[cnt], number);
}
/* Update inode bytes */
inode_reclaim_rsv_space(inode, number);
spin_unlock(&dq_data_lock);
- mark_all_dquot_dirty(i_dquot(inode));
+ mark_all_dquot_dirty(dquots);
srcu_read_unlock(&dquot_srcu, index);
return;
}
@@ -1750,7 +1763,7 @@ void __dquot_free_space(struct inode *inode, qsize_t number, int flags)
{
unsigned int cnt;
struct dquot_warn warn[MAXQUOTAS];
- struct dquot **dquots = i_dquot(inode);
+ struct dquot **dquots;
int reserve = flags & DQUOT_SPACE_RESERVE, index;
if (!dquot_active(inode)) {
@@ -1758,6 +1771,7 @@ void __dquot_free_space(struct inode *inode, qsize_t number, int flags)
return;
}
+ dquots = i_dquot(inode);
index = srcu_read_lock(&dquot_srcu);
spin_lock(&dq_data_lock);
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
@@ -1793,12 +1807,13 @@ void dquot_free_inode(struct inode *inode)
{
unsigned int cnt;
struct dquot_warn warn[MAXQUOTAS];
- struct dquot * const *dquots = i_dquot(inode);
+ struct dquot * const *dquots;
int index;
if (!dquot_active(inode))
return;
+ dquots = i_dquot(inode);
index = srcu_read_lock(&dquot_srcu);
spin_lock(&dq_data_lock);
for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/