On Thu 12-02-15 12:36:37, Konstantin Khlebnikov wrote:
> 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
Thanks. I've added the patch to my tree.
Honza
>
> 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++) {
>
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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