From: Nick Piggin <npiggin@kernel.dk>
To: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Subject: [patch 23/28] fs: dcache rationalise dget variants
Date: Wed, 17 Nov 2010 01:09:23 +1100 [thread overview]
Message-ID: <20101116142030.415925841@kernel.dk> (raw)
In-Reply-To: 20101116140900.039761100@kernel.dk
[-- Attachment #1: dcache-rationalize-dget.patch --]
[-- Type: text/plain, Size: 11150 bytes --]
dget_locked was a shortcut to avoid the lazy lru manipulation when we already
held dcache_lock (lru manipulation was relatively cheap at that point).
However, how that the lru lock is an innermost one, we never hold it at any
caller, so the lock cost can now be avoided. We already have well working lazy
dcache LRU, so it should be fine to defer LRU manipulations to scan time.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
---
arch/powerpc/platforms/cell/spufs/inode.c | 2 -
drivers/infiniband/hw/ipath/ipath_fs.c | 2 -
drivers/infiniband/hw/qib/qib_fs.c | 2 -
drivers/staging/smbfs/cache.c | 2 -
fs/configfs/inode.c | 2 -
fs/dcache.c | 34 ++++++++----------------------
fs/exportfs/expfs.c | 2 -
fs/ncpfs/dir.c | 2 -
fs/ocfs2/dcache.c | 2 -
include/linux/dcache.h | 15 ++-----------
kernel/cgroup.c | 2 -
security/selinux/selinuxfs.c | 2 -
12 files changed, 23 insertions(+), 46 deletions(-)
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/inode.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/inode.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/inode.c 2010-11-17 00:52:38.000000000 +1100
@@ -161,7 +161,7 @@ static void spufs_prune_dir(struct dentr
list_for_each_entry_safe(dentry, tmp, &dir->d_subdirs, d_u.d_child) {
spin_lock(&dentry->d_lock);
if (!(d_unhashed(dentry)) && dentry->d_inode) {
- dget_locked_dlock(dentry);
+ dget_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
simple_unlink(dir->d_inode, dentry);
Index: linux-2.6/drivers/infiniband/hw/ipath/ipath_fs.c
===================================================================
--- linux-2.6.orig/drivers/infiniband/hw/ipath/ipath_fs.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/drivers/infiniband/hw/ipath/ipath_fs.c 2010-11-17 00:52:38.000000000 +1100
@@ -279,7 +279,7 @@ static int remove_file(struct dentry *pa
spin_lock(&tmp->d_lock);
if (!(d_unhashed(tmp) && tmp->d_inode)) {
- dget_locked_dlock(tmp);
+ dget_dlock(tmp);
__d_drop(tmp);
spin_unlock(&tmp->d_lock);
simple_unlink(parent->d_inode, tmp);
Index: linux-2.6/fs/configfs/inode.c
===================================================================
--- linux-2.6.orig/fs/configfs/inode.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/configfs/inode.c 2010-11-17 00:52:38.000000000 +1100
@@ -252,7 +252,7 @@ void configfs_drop_dentry(struct configf
if (dentry) {
spin_lock(&dentry->d_lock);
if (!(d_unhashed(dentry) && dentry->d_inode)) {
- dget_locked_dlock(dentry);
+ dget_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
simple_unlink(parent->d_inode, dentry);
Index: linux-2.6/fs/dcache.c
===================================================================
--- linux-2.6.orig/fs/dcache.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/dcache.c 2010-11-17 01:05:38.000000000 +1100
@@ -389,32 +389,17 @@ int d_invalidate(struct dentry * dentry)
EXPORT_SYMBOL(d_invalidate);
/* This must be called with d_lock held */
-static inline struct dentry * __dget_locked_dlock(struct dentry *dentry)
+static inline void __dget_dlock(struct dentry *dentry)
{
dentry->d_count++;
- dentry_lru_del(dentry);
- return dentry;
}
-/* This must be called with d_lock held */
-static inline struct dentry * __dget_locked(struct dentry *dentry)
+static inline void __dget(struct dentry *dentry)
{
spin_lock(&dentry->d_lock);
- __dget_locked_dlock(dentry);
+ __dget_dlock(dentry);
spin_unlock(&dentry->d_lock);
- return dentry;
-}
-
-struct dentry * dget_locked_dlock(struct dentry *dentry)
-{
- return __dget_locked_dlock(dentry);
-}
-
-struct dentry * dget_locked(struct dentry *dentry)
-{
- return __dget_locked(dentry);
}
-EXPORT_SYMBOL(dget_locked);
struct dentry *dget_parent(struct dentry *dentry)
{
@@ -495,7 +480,7 @@ static struct dentry *__d_find_alias(str
struct dentry *alias;
alias = ___d_find_alias(inode, want_discon);
if (alias) {
- __dget_locked_dlock(alias);
+ __dget_dlock(alias);
spin_unlock(&alias->d_lock);
}
return alias;
@@ -526,7 +511,7 @@ void d_prune_aliases(struct inode *inode
list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
spin_lock(&dentry->d_lock);
if (!dentry->d_count) {
- __dget_locked_dlock(dentry);
+ __dget_dlock(dentry);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_inode_lock);
@@ -1224,7 +1209,8 @@ struct dentry *d_alloc(struct dentry * p
* don't need child lock because it is not subject
* to concurrency here
*/
- dentry->d_parent = dget_dlock(parent);
+ __dget_dlock(parent);
+ dentry->d_parent = parent;
dentry->d_sb = parent->d_sb;
list_add(&dentry->d_u.d_child, &parent->d_subdirs);
spin_unlock(&parent->d_lock);
@@ -1323,7 +1309,7 @@ static struct dentry *__d_instantiate_un
goto next;
if (memcmp(qstr->name, name, len))
goto next;
- dget_locked_dlock(alias);
+ __dget_dlock(alias);
spin_unlock(&alias->d_lock);
return alias;
next:
@@ -1579,7 +1565,7 @@ struct dentry *d_add_ci(struct dentry *d
* reference to it, move it in place and use it.
*/
new = list_entry(inode->i_dentry.next, struct dentry, d_alias);
- dget_locked(new);
+ __dget(new);
spin_unlock(&dcache_inode_lock);
security_d_instantiate(found, inode);
d_move(new, found);
@@ -1755,7 +1741,7 @@ int d_validate(struct dentry *dentry, st
list_for_each_entry(child, &dparent->d_subdirs, d_u.d_child) {
if (dentry == child) {
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
- __dget_locked_dlock(dentry);
+ __dget_dlock(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&dparent->d_lock);
return 1;
Index: linux-2.6/fs/exportfs/expfs.c
===================================================================
--- linux-2.6.orig/fs/exportfs/expfs.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/exportfs/expfs.c 2010-11-17 00:52:38.000000000 +1100
@@ -49,7 +49,7 @@ find_acceptable_alias(struct dentry *res
spin_lock(&dcache_inode_lock);
list_for_each_entry(dentry, &result->d_inode->i_dentry, d_alias) {
- dget_locked(dentry);
+ dget(dentry);
spin_unlock(&dcache_inode_lock);
if (toput)
dput(toput);
Index: linux-2.6/fs/ncpfs/dir.c
===================================================================
--- linux-2.6.orig/fs/ncpfs/dir.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/ncpfs/dir.c 2010-11-17 00:52:38.000000000 +1100
@@ -400,7 +400,7 @@ ncp_dget_fpos(struct dentry *dentry, str
dent = list_entry(next, struct dentry, d_u.d_child);
if ((unsigned long)dent->d_fsdata == fpos) {
if (dent->d_inode)
- dget_locked(dent);
+ dget(dent);
else
dent = NULL;
spin_unlock(&parent->d_lock);
Index: linux-2.6/fs/ocfs2/dcache.c
===================================================================
--- linux-2.6.orig/fs/ocfs2/dcache.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/fs/ocfs2/dcache.c 2010-11-17 00:52:38.000000000 +1100
@@ -178,7 +178,7 @@ struct dentry *ocfs2_find_local_alias(st
mlog(0, "dentry found: %.*s\n",
dentry->d_name.len, dentry->d_name.name);
- dget_locked_dlock(dentry);
+ dget_dlock(dentry);
spin_unlock(&dentry->d_lock);
break;
}
Index: linux-2.6/include/linux/dcache.h
===================================================================
--- linux-2.6.orig/include/linux/dcache.h 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/include/linux/dcache.h 2010-11-17 00:52:38.000000000 +1100
@@ -317,23 +317,17 @@ extern char *dentry_path(struct dentry *
/* Allocation counts.. */
/**
- * dget, dget_locked - get a reference to a dentry
+ * dget, dget_dlock - get a reference to a dentry
* @dentry: dentry to get a reference to
*
* Given a dentry or %NULL pointer increment the reference count
* if appropriate and return the dentry. A dentry will not be
- * destroyed when it has references. dget() should never be
- * called for dentries with zero reference counter. For these cases
- * (preferably none, functions in dcache.c are sufficient for normal
- * needs and they take necessary precautions) you should hold d_lock
- * and call dget_dlock() instead of dget().
+ * destroyed when it has references.
*/
static inline struct dentry *dget_dlock(struct dentry *dentry)
{
- if (dentry) {
- BUG_ON(!dentry->d_count);
+ if (dentry)
dentry->d_count++;
- }
return dentry;
}
@@ -347,9 +341,6 @@ static inline struct dentry *dget(struct
return dentry;
}
-extern struct dentry * dget_locked(struct dentry *);
-extern struct dentry * dget_locked_dlock(struct dentry *);
-
extern struct dentry *dget_parent(struct dentry *dentry);
/**
Index: linux-2.6/kernel/cgroup.c
===================================================================
--- linux-2.6.orig/kernel/cgroup.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/kernel/cgroup.c 2010-11-17 00:52:38.000000000 +1100
@@ -885,7 +885,7 @@ static void cgroup_clear_directory(struc
/* This should never be called on a cgroup
* directory with child cgroups */
BUG_ON(d->d_inode->i_mode & S_IFDIR);
- dget_locked_dlock(d);
+ dget_dlock(d);
spin_unlock(&d->d_lock);
spin_unlock(&dentry->d_lock);
d_delete(d);
Index: linux-2.6/security/selinux/selinuxfs.c
===================================================================
--- linux-2.6.orig/security/selinux/selinuxfs.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/security/selinux/selinuxfs.c 2010-11-17 00:52:38.000000000 +1100
@@ -1154,7 +1154,7 @@ static void sel_remove_entries(struct de
list_del_init(node);
if (d->d_inode) {
- dget_locked_dlock(d);
+ dget_dlock(d);
spin_unlock(&de->d_lock);
spin_unlock(&d->d_lock);
d_delete(d);
Index: linux-2.6/drivers/infiniband/hw/qib/qib_fs.c
===================================================================
--- linux-2.6.orig/drivers/infiniband/hw/qib/qib_fs.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/drivers/infiniband/hw/qib/qib_fs.c 2010-11-17 00:52:38.000000000 +1100
@@ -455,7 +455,7 @@ static int remove_file(struct dentry *pa
spin_lock(&tmp->d_lock);
if (!(d_unhashed(tmp) && tmp->d_inode)) {
- dget_locked_dlock(tmp);
+ dget_dlock(tmp);
__d_drop(tmp);
spin_unlock(&tmp->d_lock);
simple_unlink(parent->d_inode, tmp);
Index: linux-2.6/drivers/staging/smbfs/cache.c
===================================================================
--- linux-2.6.orig/drivers/staging/smbfs/cache.c 2010-11-17 00:52:37.000000000 +1100
+++ linux-2.6/drivers/staging/smbfs/cache.c 2010-11-17 00:52:38.000000000 +1100
@@ -102,7 +102,7 @@ smb_dget_fpos(struct dentry *dentry, str
dent = list_entry(next, struct dentry, d_u.d_child);
if ((unsigned long)dent->d_fsdata == fpos) {
if (dent->d_inode)
- dget_locked(dent);
+ dget(dent);
else
dent = NULL;
goto out_unlock;
next prev parent reply other threads:[~2010-11-16 14:24 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-16 14:09 [patch 00/28] [rfc] dcache scaling part 1 Nick Piggin
2010-11-16 14:09 ` [patch 01/28] fs: d_validate fixes Nick Piggin
2010-11-17 10:44 ` Andi Kleen
2010-11-18 20:51 ` David Miller
2010-11-18 20:59 ` David Miller
2010-11-19 5:05 ` Nick Piggin
2010-11-19 5:01 ` Nick Piggin
2010-11-16 14:09 ` [patch 02/28] kernel: kmem_ptr_validate considered harmful Nick Piggin
2010-11-16 14:09 ` [patch 03/28] fs: dcache documentation cleanup Nick Piggin
2010-11-16 14:09 ` [patch 04/28] fs: change d_delete semantics Nick Piggin
2010-11-17 0:16 ` Tim Pepper
2010-11-16 14:09 ` [patch 05/28] cifs: dont overwrite dentry name in d_revalidate Nick Piggin
2010-11-16 14:09 ` [patch 06/28] jfs: " Nick Piggin
2010-11-16 14:09 ` [patch 07/28] fs: change d_compare for rcu-walk Nick Piggin
2010-11-17 0:44 ` Tim Pepper
2010-11-16 14:09 ` [patch 08/28] fs: change d_hash " Nick Piggin
2010-11-17 0:50 ` Tim Pepper
2010-11-16 14:09 ` [patch 09/28] hostfs: simplify locking Nick Piggin
2010-11-16 14:09 ` [patch 10/28] fs: dcache scale hash Nick Piggin
2010-11-16 14:09 ` [patch 11/28] fs: dcache scale lru Nick Piggin
2010-11-16 14:09 ` [patch 12/28] fs: dcache scale dentry refcount Nick Piggin
2010-11-16 14:09 ` [patch 13/28] fs: dcache scale d_unhashed Nick Piggin
2010-11-19 19:41 ` Tim Pepper
2010-11-16 14:09 ` [patch 14/28] fs: dcache scale subdirs Nick Piggin
2010-11-19 19:41 ` Tim Pepper
2010-11-16 14:09 ` [patch 15/28] fs: scale inode alias list Nick Piggin
2010-11-19 19:41 ` Tim Pepper
2010-11-16 14:09 ` [patch 16/28] fs: Use rename lock and RCU for multi-step operations Nick Piggin
2010-11-19 19:42 ` Tim Pepper
2010-11-16 14:09 ` [patch 17/28] fs: increase d_name lock coverage Nick Piggin
2010-11-16 14:09 ` [patch 18/28] fs: dcache remove dcache_lock Nick Piggin
2010-11-16 14:09 ` [patch 19/28] fs: dcache avoid starvation in dcache multi-step operations Nick Piggin
2010-11-16 14:09 ` [patch 20/28] fs: dcache reduce dput locking Nick Piggin
2010-11-16 14:09 ` [patch 21/28] fs: dcache reduce locking in d_alloc Nick Piggin
2010-11-16 14:09 ` [patch 22/28] fs: dcache reduce dcache_inode_lock Nick Piggin
2010-11-16 14:09 ` Nick Piggin [this message]
2010-11-16 14:09 ` [patch 24/28] fs: dcache reduce d_parent locking Nick Piggin
2010-11-16 14:09 ` [patch 25/28] fs: dcache reduce prune_one_dentry locking Nick Piggin
2010-11-16 14:09 ` [patch 26/28] fs: reduce dcache_inode_lock width in lru scanning Nick Piggin
2010-11-16 14:09 ` [patch 27/28] fs: use RCU in shrink_dentry_list to reduce lock nesting Nick Piggin
2010-11-16 14:09 ` [patch 28/28] fs: consolidate dentry kill sequence Nick Piggin
2010-11-17 2:12 ` [patch 00/28] [rfc] dcache scaling part 1 Dave Chinner
2010-11-17 10:56 ` Andi Kleen
2010-11-17 11:19 ` Nick Piggin
2010-11-17 12:01 ` Andi Kleen
2010-11-19 19:43 ` Tim Pepper
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