From 5bcd3b6f639c277ed7fa71f2f8ed6fb072615011 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Thu, 12 Feb 2015 12:36:37 +0300 Subject: [PATCH] quota: optimize i_dquot access 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 Signed-off-by: Jan Kara --- 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 0ccd4ba3a246..2112ed33de41 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++) { -- 2.30.2