mirror of
https://github.com/torvalds/linux.git
synced 2024-11-22 04:02:20 +00:00
fs: dcache per-bucket dcache hash locking
We can turn the dcache hash locking from a global dcache_hash_lock into per-bucket locking. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
This commit is contained in:
Nick Piggin
parent
626d607435
commit
ceb5bdc2d2
133
fs/dcache.c
133
fs/dcache.c
@ -33,14 +33,18 @@
|
||||
#include <linux/bootmem.h>
|
||||
#include <linux/fs_struct.h>
|
||||
#include <linux/hardirq.h>
|
||||
#include <linux/bit_spinlock.h>
|
||||
#include <linux/rculist_bl.h>
|
||||
#include "internal.h"
|
||||
|
||||
/*
|
||||
* Usage:
|
||||
* dcache_inode_lock protects:
|
||||
* - i_dentry, d_alias, d_inode
|
||||
* dcache_hash_lock protects:
|
||||
* - the dcache hash table, s_anon lists
|
||||
* dcache_hash_bucket lock protects:
|
||||
* - the dcache hash table
|
||||
* s_anon bl list spinlock protects:
|
||||
* - the s_anon list (see __d_drop)
|
||||
* dcache_lru_lock protects:
|
||||
* - the dcache lru lists and counters
|
||||
* d_lock protects:
|
||||
@ -57,7 +61,8 @@
|
||||
* dcache_inode_lock
|
||||
* dentry->d_lock
|
||||
* dcache_lru_lock
|
||||
* dcache_hash_lock
|
||||
* dcache_hash_bucket lock
|
||||
* s_anon lock
|
||||
*
|
||||
* If there is an ancestor relationship:
|
||||
* dentry->d_parent->...->d_parent->d_lock
|
||||
@ -74,7 +79,6 @@ int sysctl_vfs_cache_pressure __read_mostly = 100;
|
||||
EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
|
||||
|
||||
__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_inode_lock);
|
||||
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_hash_lock);
|
||||
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock);
|
||||
__cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
|
||||
|
||||
@ -96,7 +100,29 @@ static struct kmem_cache *dentry_cache __read_mostly;
|
||||
|
||||
static unsigned int d_hash_mask __read_mostly;
|
||||
static unsigned int d_hash_shift __read_mostly;
|
||||
static struct hlist_head *dentry_hashtable __read_mostly;
|
||||
|
||||
struct dcache_hash_bucket {
|
||||
struct hlist_bl_head head;
|
||||
};
|
||||
static struct dcache_hash_bucket *dentry_hashtable __read_mostly;
|
||||
|
||||
static inline struct dcache_hash_bucket *d_hash(struct dentry *parent,
|
||||
unsigned long hash)
|
||||
{
|
||||
hash += ((unsigned long) parent ^ GOLDEN_RATIO_PRIME) / L1_CACHE_BYTES;
|
||||
hash = hash ^ ((hash ^ GOLDEN_RATIO_PRIME) >> D_HASHBITS);
|
||||
return dentry_hashtable + (hash & D_HASHMASK);
|
||||
}
|
||||
|
||||
static inline void spin_lock_bucket(struct dcache_hash_bucket *b)
|
||||
{
|
||||
bit_spin_lock(0, (unsigned long *)&b->head.first);
|
||||
}
|
||||
|
||||
static inline void spin_unlock_bucket(struct dcache_hash_bucket *b)
|
||||
{
|
||||
__bit_spin_unlock(0, (unsigned long *)&b->head.first);
|
||||
}
|
||||
|
||||
/* Statistics gathering. */
|
||||
struct dentry_stat_t dentry_stat = {
|
||||
@ -144,7 +170,7 @@ static void d_free(struct dentry *dentry)
|
||||
dentry->d_op->d_release(dentry);
|
||||
|
||||
/* if dentry was never inserted into hash, immediate free is OK */
|
||||
if (hlist_unhashed(&dentry->d_hash))
|
||||
if (hlist_bl_unhashed(&dentry->d_hash))
|
||||
__d_free(&dentry->d_u.d_rcu);
|
||||
else
|
||||
call_rcu(&dentry->d_u.d_rcu, __d_free);
|
||||
@ -302,11 +328,27 @@ static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent)
|
||||
void __d_drop(struct dentry *dentry)
|
||||
{
|
||||
if (!(dentry->d_flags & DCACHE_UNHASHED)) {
|
||||
dentry->d_flags |= DCACHE_UNHASHED;
|
||||
spin_lock(&dcache_hash_lock);
|
||||
hlist_del_rcu(&dentry->d_hash);
|
||||
spin_unlock(&dcache_hash_lock);
|
||||
dentry_rcuwalk_barrier(dentry);
|
||||
if (unlikely(dentry->d_flags & DCACHE_DISCONNECTED)) {
|
||||
bit_spin_lock(0,
|
||||
(unsigned long *)&dentry->d_sb->s_anon.first);
|
||||
dentry->d_flags |= DCACHE_UNHASHED;
|
||||
hlist_bl_del_init(&dentry->d_hash);
|
||||
__bit_spin_unlock(0,
|
||||
(unsigned long *)&dentry->d_sb->s_anon.first);
|
||||
} else {
|
||||
struct dcache_hash_bucket *b;
|
||||
b = d_hash(dentry->d_parent, dentry->d_name.hash);
|
||||
spin_lock_bucket(b);
|
||||
/*
|
||||
* We may not actually need to put DCACHE_UNHASHED
|
||||
* manipulations under the hash lock, but follow
|
||||
* the principle of least surprise.
|
||||
*/
|
||||
dentry->d_flags |= DCACHE_UNHASHED;
|
||||
hlist_bl_del_rcu(&dentry->d_hash);
|
||||
spin_unlock_bucket(b);
|
||||
dentry_rcuwalk_barrier(dentry);
|
||||
}
|
||||
}
|
||||
}
|
||||
EXPORT_SYMBOL(__d_drop);
|
||||
@ -961,8 +1003,8 @@ void shrink_dcache_for_umount(struct super_block *sb)
|
||||
spin_unlock(&dentry->d_lock);
|
||||
shrink_dcache_for_umount_subtree(dentry);
|
||||
|
||||
while (!hlist_empty(&sb->s_anon)) {
|
||||
dentry = hlist_entry(sb->s_anon.first, struct dentry, d_hash);
|
||||
while (!hlist_bl_empty(&sb->s_anon)) {
|
||||
dentry = hlist_bl_entry(hlist_bl_first(&sb->s_anon), struct dentry, d_hash);
|
||||
shrink_dcache_for_umount_subtree(dentry);
|
||||
}
|
||||
}
|
||||
@ -1263,7 +1305,7 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
|
||||
dentry->d_sb = NULL;
|
||||
dentry->d_op = NULL;
|
||||
dentry->d_fsdata = NULL;
|
||||
INIT_HLIST_NODE(&dentry->d_hash);
|
||||
INIT_HLIST_BL_NODE(&dentry->d_hash);
|
||||
INIT_LIST_HEAD(&dentry->d_lru);
|
||||
INIT_LIST_HEAD(&dentry->d_subdirs);
|
||||
INIT_LIST_HEAD(&dentry->d_alias);
|
||||
@ -1459,14 +1501,6 @@ struct dentry * d_alloc_root(struct inode * root_inode)
|
||||
}
|
||||
EXPORT_SYMBOL(d_alloc_root);
|
||||
|
||||
static inline struct hlist_head *d_hash(struct dentry *parent,
|
||||
unsigned long hash)
|
||||
{
|
||||
hash += ((unsigned long) parent ^ GOLDEN_RATIO_PRIME) / L1_CACHE_BYTES;
|
||||
hash = hash ^ ((hash ^ GOLDEN_RATIO_PRIME) >> D_HASHBITS);
|
||||
return dentry_hashtable + (hash & D_HASHMASK);
|
||||
}
|
||||
|
||||
/**
|
||||
* d_obtain_alias - find or allocate a dentry for a given inode
|
||||
* @inode: inode to allocate the dentry for
|
||||
@ -1521,11 +1555,11 @@ struct dentry *d_obtain_alias(struct inode *inode)
|
||||
tmp->d_sb = inode->i_sb;
|
||||
tmp->d_inode = inode;
|
||||
tmp->d_flags |= DCACHE_DISCONNECTED;
|
||||
tmp->d_flags &= ~DCACHE_UNHASHED;
|
||||
list_add(&tmp->d_alias, &inode->i_dentry);
|
||||
spin_lock(&dcache_hash_lock);
|
||||
hlist_add_head(&tmp->d_hash, &inode->i_sb->s_anon);
|
||||
spin_unlock(&dcache_hash_lock);
|
||||
bit_spin_lock(0, (unsigned long *)&tmp->d_sb->s_anon.first);
|
||||
tmp->d_flags &= ~DCACHE_UNHASHED;
|
||||
hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon);
|
||||
__bit_spin_unlock(0, (unsigned long *)&tmp->d_sb->s_anon.first);
|
||||
spin_unlock(&tmp->d_lock);
|
||||
spin_unlock(&dcache_inode_lock);
|
||||
|
||||
@ -1567,7 +1601,7 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
|
||||
d_move(new, dentry);
|
||||
iput(inode);
|
||||
} else {
|
||||
/* already taking dcache_inode_lock, so d_add() by hand */
|
||||
/* already got dcache_inode_lock, so d_add() by hand */
|
||||
__d_instantiate(dentry, inode);
|
||||
spin_unlock(&dcache_inode_lock);
|
||||
security_d_instantiate(dentry, inode);
|
||||
@ -1702,8 +1736,8 @@ struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name,
|
||||
unsigned int len = name->len;
|
||||
unsigned int hash = name->hash;
|
||||
const unsigned char *str = name->name;
|
||||
struct hlist_head *head = d_hash(parent, hash);
|
||||
struct hlist_node *node;
|
||||
struct dcache_hash_bucket *b = d_hash(parent, hash);
|
||||
struct hlist_bl_node *node;
|
||||
struct dentry *dentry;
|
||||
|
||||
/*
|
||||
@ -1726,7 +1760,7 @@ struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name,
|
||||
*
|
||||
* See Documentation/vfs/dcache-locking.txt for more details.
|
||||
*/
|
||||
hlist_for_each_entry_rcu(dentry, node, head, d_hash) {
|
||||
hlist_bl_for_each_entry_rcu(dentry, node, &b->head, d_hash) {
|
||||
struct inode *i;
|
||||
const char *tname;
|
||||
int tlen;
|
||||
@ -1820,8 +1854,8 @@ struct dentry *__d_lookup(struct dentry *parent, struct qstr *name)
|
||||
unsigned int len = name->len;
|
||||
unsigned int hash = name->hash;
|
||||
const unsigned char *str = name->name;
|
||||
struct hlist_head *head = d_hash(parent,hash);
|
||||
struct hlist_node *node;
|
||||
struct dcache_hash_bucket *b = d_hash(parent, hash);
|
||||
struct hlist_bl_node *node;
|
||||
struct dentry *found = NULL;
|
||||
struct dentry *dentry;
|
||||
|
||||
@ -1847,7 +1881,7 @@ struct dentry *__d_lookup(struct dentry *parent, struct qstr *name)
|
||||
*/
|
||||
rcu_read_lock();
|
||||
|
||||
hlist_for_each_entry_rcu(dentry, node, head, d_hash) {
|
||||
hlist_bl_for_each_entry_rcu(dentry, node, &b->head, d_hash) {
|
||||
const char *tname;
|
||||
int tlen;
|
||||
|
||||
@ -1998,11 +2032,13 @@ again:
|
||||
}
|
||||
EXPORT_SYMBOL(d_delete);
|
||||
|
||||
static void __d_rehash(struct dentry * entry, struct hlist_head *list)
|
||||
static void __d_rehash(struct dentry * entry, struct dcache_hash_bucket *b)
|
||||
{
|
||||
|
||||
BUG_ON(!d_unhashed(entry));
|
||||
spin_lock_bucket(b);
|
||||
entry->d_flags &= ~DCACHE_UNHASHED;
|
||||
hlist_add_head_rcu(&entry->d_hash, list);
|
||||
hlist_bl_add_head_rcu(&entry->d_hash, &b->head);
|
||||
spin_unlock_bucket(b);
|
||||
}
|
||||
|
||||
static void _d_rehash(struct dentry * entry)
|
||||
@ -2020,9 +2056,7 @@ static void _d_rehash(struct dentry * entry)
|
||||
void d_rehash(struct dentry * entry)
|
||||
{
|
||||
spin_lock(&entry->d_lock);
|
||||
spin_lock(&dcache_hash_lock);
|
||||
_d_rehash(entry);
|
||||
spin_unlock(&dcache_hash_lock);
|
||||
spin_unlock(&entry->d_lock);
|
||||
}
|
||||
EXPORT_SYMBOL(d_rehash);
|
||||
@ -2165,15 +2199,16 @@ void d_move(struct dentry * dentry, struct dentry * target)
|
||||
write_seqcount_begin(&dentry->d_seq);
|
||||
write_seqcount_begin(&target->d_seq);
|
||||
|
||||
/* Move the dentry to the target hash queue, if on different bucket */
|
||||
spin_lock(&dcache_hash_lock);
|
||||
if (!d_unhashed(dentry))
|
||||
hlist_del_rcu(&dentry->d_hash);
|
||||
/* __d_drop does write_seqcount_barrier, but they're OK to nest. */
|
||||
|
||||
/*
|
||||
* Move the dentry to the target hash queue. Don't bother checking
|
||||
* for the same hash queue because of how unlikely it is.
|
||||
*/
|
||||
__d_drop(dentry);
|
||||
__d_rehash(dentry, d_hash(target->d_parent, target->d_name.hash));
|
||||
spin_unlock(&dcache_hash_lock);
|
||||
|
||||
/* Unhash the target: dput() will then get rid of it */
|
||||
/* __d_drop does write_seqcount_barrier, but they're OK to nest. */
|
||||
__d_drop(target);
|
||||
|
||||
list_del(&dentry->d_u.d_child);
|
||||
@ -2369,9 +2404,7 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
|
||||
|
||||
spin_lock(&actual->d_lock);
|
||||
found:
|
||||
spin_lock(&dcache_hash_lock);
|
||||
_d_rehash(actual);
|
||||
spin_unlock(&dcache_hash_lock);
|
||||
spin_unlock(&actual->d_lock);
|
||||
spin_unlock(&dcache_inode_lock);
|
||||
out_nolock:
|
||||
@ -2953,7 +2986,7 @@ static void __init dcache_init_early(void)
|
||||
|
||||
dentry_hashtable =
|
||||
alloc_large_system_hash("Dentry cache",
|
||||
sizeof(struct hlist_head),
|
||||
sizeof(struct dcache_hash_bucket),
|
||||
dhash_entries,
|
||||
13,
|
||||
HASH_EARLY,
|
||||
@ -2962,7 +2995,7 @@ static void __init dcache_init_early(void)
|
||||
0);
|
||||
|
||||
for (loop = 0; loop < (1 << d_hash_shift); loop++)
|
||||
INIT_HLIST_HEAD(&dentry_hashtable[loop]);
|
||||
INIT_HLIST_BL_HEAD(&dentry_hashtable[loop].head);
|
||||
}
|
||||
|
||||
static void __init dcache_init(void)
|
||||
@ -2985,7 +3018,7 @@ static void __init dcache_init(void)
|
||||
|
||||
dentry_hashtable =
|
||||
alloc_large_system_hash("Dentry cache",
|
||||
sizeof(struct hlist_head),
|
||||
sizeof(struct dcache_hash_bucket),
|
||||
dhash_entries,
|
||||
13,
|
||||
0,
|
||||
@ -2994,7 +3027,7 @@ static void __init dcache_init(void)
|
||||
0);
|
||||
|
||||
for (loop = 0; loop < (1 << d_hash_shift); loop++)
|
||||
INIT_HLIST_HEAD(&dentry_hashtable[loop]);
|
||||
INIT_HLIST_BL_HEAD(&dentry_hashtable[loop].head);
|
||||
}
|
||||
|
||||
/* SLAB cache for __getname() consumers */
|
||||
|
||||
@ -30,6 +30,7 @@
|
||||
#include <linux/idr.h>
|
||||
#include <linux/mutex.h>
|
||||
#include <linux/backing-dev.h>
|
||||
#include <linux/rculist_bl.h>
|
||||
#include "internal.h"
|
||||
|
||||
|
||||
@ -71,7 +72,7 @@ static struct super_block *alloc_super(struct file_system_type *type)
|
||||
INIT_LIST_HEAD(&s->s_files);
|
||||
#endif
|
||||
INIT_LIST_HEAD(&s->s_instances);
|
||||
INIT_HLIST_HEAD(&s->s_anon);
|
||||
INIT_HLIST_BL_HEAD(&s->s_anon);
|
||||
INIT_LIST_HEAD(&s->s_inodes);
|
||||
INIT_LIST_HEAD(&s->s_dentry_lru);
|
||||
init_rwsem(&s->s_umount);
|
||||
|
||||
@ -4,6 +4,7 @@
|
||||
#include <asm/atomic.h>
|
||||
#include <linux/list.h>
|
||||
#include <linux/rculist.h>
|
||||
#include <linux/rculist_bl.h>
|
||||
#include <linux/spinlock.h>
|
||||
#include <linux/seqlock.h>
|
||||
#include <linux/cache.h>
|
||||
@ -95,7 +96,7 @@ struct dentry {
|
||||
/* RCU lookup touched fields */
|
||||
unsigned int d_flags; /* protected by d_lock */
|
||||
seqcount_t d_seq; /* per dentry seqlock */
|
||||
struct hlist_node d_hash; /* lookup hash list */
|
||||
struct hlist_bl_node d_hash; /* lookup hash list */
|
||||
struct dentry *d_parent; /* parent directory */
|
||||
struct qstr d_name;
|
||||
struct inode *d_inode; /* Where the name belongs to - NULL is
|
||||
|
||||
@ -392,6 +392,7 @@ struct inodes_stat_t {
|
||||
#include <linux/capability.h>
|
||||
#include <linux/semaphore.h>
|
||||
#include <linux/fiemap.h>
|
||||
#include <linux/rculist_bl.h>
|
||||
|
||||
#include <asm/atomic.h>
|
||||
#include <asm/byteorder.h>
|
||||
@ -1377,7 +1378,7 @@ struct super_block {
|
||||
const struct xattr_handler **s_xattr;
|
||||
|
||||
struct list_head s_inodes; /* all inodes */
|
||||
struct hlist_head s_anon; /* anonymous dentries for (nfs) exporting */
|
||||
struct hlist_bl_head s_anon; /* anonymous dentries for (nfs) exporting */
|
||||
#ifdef CONFIG_SMP
|
||||
struct list_head __percpu *s_files;
|
||||
#else
|
||||
|
||||
Loading…
Reference in New Issue
Block a user