Re: [RFC/PATCH] ext3: remove inode constructor

2007-05-05 Thread Andrew Morton 
On Sat, 5 May 2007 11:58:45 +0300 (EEST) Pekka J Enberg [EMAIL PROTECTED] 
wrote:

 On Fri, 4 May 2007, Andrew Morton wrote:
  I got 100% rejects against this because Christoph has already had
  his paws all over the slab constructor code everywhere.
  
  Was going to fix it up but then decided that we ought to make changes
  like this to ext4 as well.  Ideally beforehand, but simultaneously is
  OK as long as it's simple enough.
 
 I'll send you proper patches for them (and will convert other filesystems 
 too).

May as well.

 On Fri, 4 May 2007, Andrew Morton wrote:
  btw, for a benchmark I'd suggest just a silly create-1-files
  tight loop rather than something more complex like postmark.
 
 Do you want me to redo the benchmarks or are you happy enough with the 
 postmark numbers?

I doubt if this is measurable, really.  It'll be something like the
difference between an L1 hit and an L2 hit in amongst all the other stuff
we do on a per-inode basis.

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Re: [RFC/PATCH] ext3: remove inode constructor

2007-05-05 Thread Pekka J Enberg 
On Fri, 4 May 2007, Christoph Lameter wrote:
 Also could this be generalized to also apply to the generic inode 
 allocation in fs/inode.c?

I think we want to stick inode_init_ince() in alloc_inode() but we can't 
do that until all filesystems are converted over.

Pekka
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[RFC/PATCH] ext3: remove inode constructor

2007-05-04 Thread Pekka J Enberg 
From: Pekka Enberg [EMAIL PROTECTED]

As explained by Christoph Lameter, ext3_alloc_inode() touches the same
cache line as init_once() so we gain nothing from using slab
constructors.  The SLUB allocator will be more effective without it
(free pointer can be placed inside the free'd object), so move inode
initialization to ext3_alloc_inode completely.

[postmark: numbers = 1, transactions = 1, 2 GHz Pentium M]

2.6.21 vanilla:

  real  0m19.006s
  user  0m0.144s
  sys   0m7.424s

  real  0m9.040s
  user  0m0.156s
  sys   0m5.164s

  real  0m8.939s
  user  0m0.128s
  sys   0m5.180s

2.6.21 + ext3-remove-inode-constructor:

  real  0m19.176s
  user  0m0.176s
  sys   0m7.436s

  real  0m9.030s
  user  0m0.172s
  sys   0m5.120s

  real  0m8.966s
  user  0m0.168s
  sys   0m5.132s

Cc: Stephen C. Tweedie [EMAIL PROTECTED]
Cc: Andrew Morton [EMAIL PROTECTED]
Cc: Andreas Dilger [EMAIL PROTECTED]
Cc: Christoph Lameter [EMAIL PROTECTED]
Signed-off-by: Pekka Enberg [EMAIL PROTECTED]
---
 fs/ext3/super.c |   30 --
 1 file changed, 12 insertions(+), 18 deletions(-)

Index: 2.6/fs/ext3/super.c
===
--- 2.6.orig/fs/ext3/super.c2007-05-04 12:57:09.0 +0300
+++ 2.6/fs/ext3/super.c 2007-05-04 13:01:27.0 +0300
@@ -444,17 +444,26 @@ static struct kmem_cache *ext3_inode_cac
 static struct inode *ext3_alloc_inode(struct super_block *sb)
 {
struct ext3_inode_info *ei;
+   struct inode *inode;
 
ei = kmem_cache_alloc(ext3_inode_cachep, GFP_NOFS);
if (!ei)
return NULL;
+INIT_LIST_HEAD(ei-i_orphan);
+#ifdef CONFIG_EXT3_FS_XATTR
+init_rwsem(ei-xattr_sem);
+#endif
+mutex_init(ei-truncate_mutex);
 #ifdef CONFIG_EXT3_FS_POSIX_ACL
ei-i_acl = EXT3_ACL_NOT_CACHED;
ei-i_default_acl = EXT3_ACL_NOT_CACHED;
 #endif
ei-i_block_alloc_info = NULL;
-   ei-vfs_inode.i_version = 1;
-   return ei-vfs_inode;
+
+   inode = ei-vfs_inode;
+   inode_init_once(inode);
+   inode-i_version = 1;
+   return inode;
 }
 
 static void ext3_destroy_inode(struct inode *inode)
@@ -462,28 +471,13 @@ static void ext3_destroy_inode(struct in
kmem_cache_free(ext3_inode_cachep, EXT3_I(inode));
 }
 
-static void init_once(void * foo, struct kmem_cache * cachep, unsigned long 
flags)
-{
-   struct ext3_inode_info *ei = (struct ext3_inode_info *) foo;
-
-   if ((flags  (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
-   SLAB_CTOR_CONSTRUCTOR) {
-   INIT_LIST_HEAD(ei-i_orphan);
-#ifdef CONFIG_EXT3_FS_XATTR
-   init_rwsem(ei-xattr_sem);
-#endif
-   mutex_init(ei-truncate_mutex);
-   inode_init_once(ei-vfs_inode);
-   }
-}
-
 static int init_inodecache(void)
 {
ext3_inode_cachep = kmem_cache_create(ext3_inode_cache,
 sizeof(struct ext3_inode_info),
 0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
-init_once, NULL);
+NULL, NULL);
if (ext3_inode_cachep == NULL)
return -ENOMEM;
return 0;
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Re: [RFC/PATCH] ext3: remove inode constructor

2007-05-04 Thread Christoph Lameter 
On Fri, 4 May 2007, Pekka J Enberg wrote:

 Index: 2.6/fs/ext3/super.c
 ===
 --- 2.6.orig/fs/ext3/super.c  2007-05-04 12:57:09.0 +0300
 +++ 2.6/fs/ext3/super.c   2007-05-04 13:01:27.0 +0300
 @@ -444,17 +444,26 @@ static struct kmem_cache *ext3_inode_cac
  static struct inode *ext3_alloc_inode(struct super_block *sb)
  {
   struct ext3_inode_info *ei;
 + struct inode *inode;
  
   ei = kmem_cache_alloc(ext3_inode_cachep, GFP_NOFS);
   if (!ei)
   return NULL;
 +INIT_LIST_HEAD(ei-i_orphan);
 +#ifdef CONFIG_EXT3_FS_XATTR
 +init_rwsem(ei-xattr_sem);
 +#endif
 +mutex_init(ei-truncate_mutex);

^^^ whitespace issues

Also could this be generalized to also apply to the generic inode 
allocation in fs/inode.c?

-
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Re: [RFC/PATCH] ext3: remove inode constructor

2007-05-04 Thread Andrew Morton 
On Fri, 4 May 2007 13:14:35 +0300 (EEST)
Pekka J Enberg [EMAIL PROTECTED] wrote:

 As explained by Christoph Lameter, ext3_alloc_inode() touches the same
 cache line as init_once() so we gain nothing from using slab
 constructors.  The SLUB allocator will be more effective without it
 (free pointer can be placed inside the free'd object), so move inode
 initialization to ext3_alloc_inode completely.

I got 100% rejects against this because Christoph has already had
his paws all over the slab constructor code everywhere.

Was going to fix it up but then decided that we ought to make changes
like this to ext4 as well.  Ideally beforehand, but simultaneously is
OK as long as it's simple enough.

btw, for a benchmark I'd suggest just a silly create-1-files
tight loop rather than something more complex like postmark.
-
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