From: npiggin@suse.de
To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [patch 08/14] fs: scale inode alias list
Date: Mon, 30 Mar 2009 02:55:47 +1100 [thread overview]
Message-ID: <20090329155749.455863870@nick.local0.net> (raw)
In-Reply-To: <20090329155539.275927173@nick.local0.net>
[-- Attachment #1: fs-dcache-scale-i_dentry.patch --]
[-- Type: text/plain, Size: 10749 bytes --]
Add a new lock, dcache_inode_lock, to protect the inode's i_dentry list
from concurrent modification. d_alias is also protected by d_lock.
---
fs/dcache.c | 56 +++++++++++++++++++++++++++++++++++++++-----
fs/notify/inotify/inotify.c | 2 +
fs/sysfs/dir.c | 3 ++
include/linux/dcache.h | 1
4 files changed, 56 insertions(+), 6 deletions(-)
Index: linux-2.6/fs/dcache.c
===================================================================
--- linux-2.6.orig/fs/dcache.c
+++ linux-2.6/fs/dcache.c
@@ -36,6 +36,8 @@
/*
* Usage:
+ * dcache_inode_lock protects:
+ * - the inode alias lists, d_inode
* dcache_hash_lock protects:
* - the dcache hash table
* dcache_lru_lock protects:
@@ -49,18 +51,21 @@
*
* Ordering:
* dcache_lock
- * dentry->d_lock
- * dcache_lru_lock
- * dcache_hash_lock
+ * dcache_inode_lock
+ * dentry->d_lock
+ * dcache_lru_lock
+ * dcache_hash_lock
*/
int sysctl_vfs_cache_pressure __read_mostly = 100;
EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
+__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_inode_lock);
__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_hash_lock);
__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock);
__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lock);
__cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
+EXPORT_SYMBOL(dcache_inode_lock);
EXPORT_SYMBOL(dcache_hash_lock);
EXPORT_SYMBOL(dcache_lock);
@@ -124,6 +129,7 @@ static void d_free(struct dentry *dentry
*/
static void dentry_iput(struct dentry * dentry)
__releases(dentry->d_lock)
+ __releases(dcache_inode_lock)
__releases(dcache_lock)
{
struct inode *inode = dentry->d_inode;
@@ -131,6 +137,7 @@ static void dentry_iput(struct dentry *
dentry->d_inode = NULL;
list_del_init(&dentry->d_alias);
spin_unlock(&dentry->d_lock);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
if (!inode->i_nlink)
fsnotify_inoderemove(inode);
@@ -140,6 +147,7 @@ static void dentry_iput(struct dentry *
iput(inode);
} else {
spin_unlock(&dentry->d_lock);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
}
}
@@ -211,6 +219,7 @@ static void dentry_lru_del_init(struct d
*/
static struct dentry *d_kill(struct dentry *dentry)
__releases(dentry->d_lock)
+ __releases(dcache_inode_lock)
__releases(dcache_lock)
{
struct dentry *parent;
@@ -275,16 +284,21 @@ repeat:
* want to reduce dcache_lock anyway so this will
* get improved.
*/
+drop1:
spin_unlock(&dentry->d_lock);
goto repeat;
}
+ if (!spin_trylock(&dcache_inode_lock)) {
+drop2:
+ spin_unlock(&dcache_lock);
+ goto drop1;
+ }
parent = dentry->d_parent;
if (parent) {
BUG_ON(parent == dentry);
if (!spin_trylock(&parent->d_lock)) {
- spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
- goto repeat;
+ spin_unlock(&dcache_inode_lock);
+ goto drop2;
}
}
}
@@ -311,6 +325,7 @@ repeat:
spin_unlock(&dentry->d_lock);
if (parent)
spin_unlock(&parent->d_lock);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
return;
@@ -463,7 +478,9 @@ struct dentry * d_find_alias(struct inod
if (!list_empty(&inode->i_dentry)) {
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
de = __d_find_alias(inode, 0);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
}
return de;
@@ -478,18 +495,21 @@ void d_prune_aliases(struct inode *inode
struct dentry *dentry;
restart:
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
spin_lock(&dentry->d_lock);
if (!dentry->d_count) {
__dget_locked_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
dput(dentry);
goto restart;
}
spin_unlock(&dentry->d_lock);
}
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
}
@@ -517,6 +537,7 @@ static void prune_one_dentry(struct dent
struct dentry *parent = NULL;
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
again:
spin_lock(&dentry->d_lock);
if (dentry->d_parent && dentry != dentry->d_parent) {
@@ -531,6 +552,7 @@ again:
if (parent)
spin_unlock(&parent->d_lock);
spin_unlock(&dentry->d_lock);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
return;
}
@@ -601,6 +623,7 @@ restart:
spin_unlock(&dcache_lru_lock);
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
again:
spin_lock(&dcache_lru_lock); /* lru_lock also protects tmp list */
while (!list_empty(&tmp)) {
@@ -633,8 +656,10 @@ again1:
prune_one_dentry(dentry);
/* dcache_lock and dentry->d_lock dropped */
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
spin_lock(&dcache_lru_lock);
}
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
if (count == NULL && !list_empty(&sb->s_dentry_lru))
@@ -1169,7 +1194,9 @@ void d_instantiate(struct dentry *entry,
{
BUG_ON(!list_empty(&entry->d_alias));
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
__d_instantiate(entry, inode);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
security_d_instantiate(entry, inode);
}
@@ -1229,7 +1256,9 @@ struct dentry *d_instantiate_unique(stru
BUG_ON(!list_empty(&entry->d_alias));
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
result = __d_instantiate_unique(entry, inode);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
if (!result) {
@@ -1319,8 +1348,10 @@ struct dentry *d_obtain_alias(struct ino
tmp->d_parent = tmp; /* make sure dput doesn't croak */
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
res = __d_find_alias(inode, 0);
if (res) {
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
dput(tmp);
goto out_iput;
@@ -1335,6 +1366,7 @@ struct dentry *d_obtain_alias(struct ino
list_add(&tmp->d_alias, &inode->i_dentry);
hlist_add_head(&tmp->d_hash, &inode->i_sb->s_anon);
spin_unlock(&tmp->d_lock);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
return tmp;
@@ -1367,9 +1399,11 @@ struct dentry *d_splice_alias(struct ino
if (inode && S_ISDIR(inode->i_mode)) {
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
new = __d_find_alias(inode, 1);
if (new) {
BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED));
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
security_d_instantiate(new, inode);
d_rehash(dentry);
@@ -1378,6 +1412,7 @@ struct dentry *d_splice_alias(struct ino
} else {
/* already taking dcache_lock, so d_add() by hand */
__d_instantiate(dentry, inode);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
security_d_instantiate(dentry, inode);
d_rehash(dentry);
@@ -1454,6 +1489,7 @@ struct dentry *d_add_ci(struct dentry *d
return found;
}
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
if (list_empty(&inode->i_dentry)) {
/*
* Directory without a 'disconnected' dentry; we need to do
@@ -1461,6 +1497,7 @@ struct dentry *d_add_ci(struct dentry *d
* we already hold.
*/
__d_instantiate(found, inode);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
security_d_instantiate(found, inode);
return found;
@@ -1471,6 +1508,7 @@ struct dentry *d_add_ci(struct dentry *d
*/
new = list_entry(inode->i_dentry.next, struct dentry, d_alias);
dget_locked(new);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
/* Do security vodoo. */
security_d_instantiate(found, inode);
@@ -1688,6 +1726,7 @@ void d_delete(struct dentry * dentry)
* Are we the only user?
*/
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
spin_lock(&dentry->d_lock);
isdir = S_ISDIR(dentry->d_inode->i_mode);
if (dentry->d_count == 1) {
@@ -1700,6 +1739,7 @@ void d_delete(struct dentry * dentry)
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
fsnotify_nameremove(dentry, isdir);
@@ -1944,6 +1984,7 @@ out_unalias:
d_move_locked(alias, dentry);
ret = alias;
out_err:
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
if (m2)
mutex_unlock(m2);
@@ -2009,6 +2050,7 @@ struct dentry *d_materialise_unique(stru
BUG_ON(!d_unhashed(dentry));
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
if (!inode) {
actual = dentry;
@@ -2053,6 +2095,7 @@ found:
_d_rehash(actual);
spin_unlock(&dcache_hash_lock);
spin_unlock(&actual->d_lock);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
out_nolock:
if (actual == dentry) {
@@ -2064,6 +2107,7 @@ out_nolock:
return actual;
shouldnt_be_hashed:
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
BUG();
}
Index: linux-2.6/fs/sysfs/dir.c
===================================================================
--- linux-2.6.orig/fs/sysfs/dir.c
+++ linux-2.6/fs/sysfs/dir.c
@@ -520,6 +520,7 @@ static void sysfs_drop_dentry(struct sys
*/
repeat:
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
spin_lock(&dentry->d_lock);
if (d_unhashed(dentry)) {
@@ -529,10 +530,12 @@ repeat:
dget_locked_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
dput(dentry);
goto repeat;
}
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
/* adjust nlink and update timestamp */
Index: linux-2.6/include/linux/dcache.h
===================================================================
--- linux-2.6.orig/include/linux/dcache.h
+++ linux-2.6/include/linux/dcache.h
@@ -184,6 +184,7 @@ d_iput: no no no yes
#define DCACHE_COOKIE 0x0040 /* For use by dcookie subsystem */
+extern spinlock_t dcache_inode_lock;
extern spinlock_t dcache_hash_lock;
extern spinlock_t dcache_lock;
extern seqlock_t rename_lock;
Index: linux-2.6/fs/notify/inotify/inotify.c
===================================================================
--- linux-2.6.orig/fs/notify/inotify/inotify.c
+++ linux-2.6/fs/notify/inotify/inotify.c
@@ -185,6 +185,7 @@ static void set_dentry_child_flags(struc
struct dentry *alias;
spin_lock(&dcache_lock);
+ spin_lock(&dcache_inode_lock);
list_for_each_entry(alias, &inode->i_dentry, d_alias) {
struct dentry *child;
@@ -202,6 +203,7 @@ static void set_dentry_child_flags(struc
}
spin_unlock(&alias->d_lock);
}
+ spin_unlock(&dcache_inode_lock);
spin_unlock(&dcache_lock);
}
next prev parent reply other threads:[~2009-03-29 16:42 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-29 15:55 [rfc] scale dcache locking npiggin
2009-03-29 15:55 ` [patch 01/14] fs: dcache fix LRU ordering npiggin
2009-03-29 15:55 ` [patch 02/14] fs: dcache scale hash npiggin
2009-03-29 15:55 ` [patch 03/14] fs: dcache scale lru npiggin
2009-03-29 15:55 ` [patch 04/14] fs: dcache scale nr_dentry npiggin
2009-03-29 15:55 ` [patch 05/14] fs: dcache scale dentry refcount npiggin
2009-03-29 15:55 ` [patch 06/14] fs: dcache scale d_unhashed npiggin
2009-03-29 15:55 ` [patch 07/14] fs: dcache scale subdirs npiggin
2009-03-29 15:55 ` npiggin [this message]
2009-03-30 12:18 ` [patch 08/14] fs: scale inode alias list Andi Kleen
2009-03-30 12:31 ` Nick Piggin
2009-03-29 15:55 ` [patch 09/14] fs: use RCU / seqlock logic for reverse and multi-step operaitons npiggin
2009-03-30 12:16 ` Andi Kleen
2009-03-30 12:29 ` Nick Piggin
2009-03-30 12:43 ` Andi Kleen
2009-03-29 15:55 ` [patch 10/14] fs: dcache remove dcache_lock npiggin
2009-03-29 15:55 ` [patch 11/14] fs: dcache reduce dput locking npiggin
2009-03-29 15:55 ` [patch 12/14] fs: dcache per-bucket dcache hash locking npiggin
2009-03-30 12:14 ` Andi Kleen
2009-03-30 12:27 ` Nick Piggin
2009-03-30 12:47 ` Andi Kleen
2009-03-30 12:59 ` Nick Piggin
2009-03-30 18:00 ` Christoph Hellwig
2009-03-31 1:57 ` Nick Piggin
2009-03-29 15:55 ` [patch 13/14] fs: dcache reduce dcache_inode_lock npiggin
2009-03-29 15:55 ` [patch 14/14] fs: dcache per-inode inode alias locking npiggin
2009-04-01 14:23 ` [rfc] scale dcache locking Al Viro
2009-04-02 9:43 ` Nick Piggin
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