From: npiggin@kernel.dk
To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: [patch 12/35] fs: inode atomic last_ino, iunique lock
Date: Tue, 19 Oct 2010 14:42:28 +1100 [thread overview]
Message-ID: <20101019034656.732498317@kernel.dk> (raw)
In-Reply-To: 20101019034216.319085068@kernel.dk
[-- Attachment #1: fs-inode_lock-scale-6c.patch --]
[-- Type: text/plain, Size: 2507 bytes --]
Make last_ino atomic in preperation for removing inode_lock.
Make a new lock for iunique counter, for removing inode_lock.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
---
fs/inode.c | 37 +++++++++++++++++++++++++++++--------
1 file changed, 29 insertions(+), 8 deletions(-)
Index: linux-2.6/fs/inode.c
===================================================================
--- linux-2.6.orig/fs/inode.c 2010-10-19 14:18:59.000000000 +1100
+++ linux-2.6/fs/inode.c 2010-10-19 14:19:32.000000000 +1100
@@ -742,7 +742,7 @@
* error if st_ino won't fit in target struct field. Use 32bit counter
* here to attempt to avoid that.
*/
- static unsigned int last_ino;
+ static atomic_t last_ino = ATOMIC_INIT(0);
struct inode *inode;
spin_lock_prefetch(&inode_lock);
@@ -752,7 +752,7 @@
spin_lock(&inode_lock);
spin_lock(&sb_inode_list_lock);
spin_lock(&inode->i_lock);
- inode->i_ino = ++last_ino;
+ inode->i_ino = (unsigned int)atomic_inc_return(&last_ino);
inode->i_state = 0;
__inode_add_to_lists(sb, NULL, inode);
spin_unlock(&inode->i_lock);
@@ -903,6 +903,29 @@
return inode;
}
+/* Is the ino for this sb hashed right now? */
+static int is_ino_hashed(struct super_block *sb, unsigned long ino)
+{
+ struct hlist_node *node;
+ struct inode *inode = NULL;
+ struct hlist_head *head = inode_hashtable + hash(sb, ino);
+
+ spin_lock(&inode_hash_lock);
+ hlist_for_each_entry(inode, node, head, i_hash) {
+ if (inode->i_ino == ino && inode->i_sb == sb) {
+ spin_unlock(&inode_hash_lock);
+ return 0;
+ }
+ /*
+ * Don't bother checking for I_FREEING etc., because
+ * we don't want iunique to wait on freeing inodes. Just
+ * skip it and get the next one.
+ */
+ }
+ spin_unlock(&inode_hash_lock);
+ return 1;
+}
+
/**
* iunique - get a unique inode number
* @sb: superblock
@@ -924,20 +947,18 @@
* error if st_ino won't fit in target struct field. Use 32bit counter
* here to attempt to avoid that.
*/
+ static DEFINE_SPINLOCK(unique_lock);
static unsigned int counter;
- struct inode *inode;
- struct hlist_head *head;
ino_t res;
spin_lock(&inode_lock);
+ spin_lock(&unique_lock);
do {
if (counter <= max_reserved)
counter = max_reserved + 1;
res = counter++;
- head = inode_hashtable + hash(sb, res);
- inode = find_inode_fast(sb, head, res);
- spin_unlock(&inode->i_lock);
- } while (inode != NULL);
+ } while (!is_ino_hashed(sb, res));
+ spin_unlock(&unique_lock);
spin_unlock(&inode_lock);
return res;
next prev parent reply other threads:[~2010-10-19 3:56 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-19 3:42 [patch 00/35] my inode scaling series for review npiggin
2010-10-19 3:42 ` [patch 01/35] bit_spinlock: add required includes npiggin
2010-10-19 3:42 ` [patch 02/35] kernel: add bl_list npiggin
2010-10-19 3:42 ` [patch 03/35] mm: implement per-zone shrinker npiggin
2010-10-19 4:49 ` KOSAKI Motohiro
2010-10-19 5:33 ` Nick Piggin
2010-10-19 5:40 ` KOSAKI Motohiro
2010-10-19 3:42 ` [patch 04/35] vfs: convert inode and dentry caches to " npiggin
2010-10-19 3:42 ` [patch 05/35] fs: icache lock s_inodes list npiggin
2010-10-19 3:42 ` [patch 06/35] fs: icache lock inode hash npiggin
2010-10-19 3:42 ` [patch 07/35] fs: icache lock i_state npiggin
2010-10-19 10:47 ` Miklos Szeredi
2010-10-19 17:06 ` Peter Zijlstra
2010-10-19 3:42 ` [patch 08/35] fs: icache lock i_count npiggin
2010-10-19 10:16 ` Boaz Harrosh
2010-10-20 2:14 ` Nick Piggin
2010-10-19 3:42 ` [patch 09/35] fs: icache lock lru/writeback lists npiggin
2010-10-19 3:42 ` [patch 10/35] fs: icache atomic inodes_stat npiggin
2010-10-19 3:42 ` [patch 11/35] fs: icache lock inode state npiggin
2010-10-19 3:42 ` npiggin [this message]
2010-10-19 3:42 ` [patch 13/35] fs: icache remove inode_lock npiggin
2010-10-19 3:42 ` [patch 14/35] fs: icache factor hash lock into functions npiggin
2010-10-19 3:42 ` [patch 15/35] fs: icache per-bucket inode hash locks npiggin
2010-10-19 3:42 ` [patch 16/35] fs: icache lazy inode lru npiggin
2010-10-19 3:42 ` [patch 17/35] fs: icache RCU free inodes npiggin
2010-10-19 3:42 ` [patch 18/35] fs: avoid inode RCU freeing for pseudo fs npiggin
2010-10-19 3:42 ` [patch 19/35] fs: icache remove redundant i_sb_list umount locking npiggin
2010-10-20 12:46 ` Al Viro
2010-10-20 13:03 ` Nick Piggin
2010-10-20 13:27 ` Al Viro
2010-10-19 3:42 ` [patch 20/35] fs: icache rcu walk for i_sb_list npiggin
2010-10-19 3:42 ` [patch 21/35] fs: icache per-cpu nr_inodes, non-atomic nr_unused counters npiggin
2010-10-19 3:42 ` [patch 22/35] fs: icache per-cpu last_ino allocator npiggin
2010-10-19 3:42 ` [patch 23/35] fs: icache use per-CPU lists and locks for sb inode lists npiggin
2010-10-19 15:33 ` Miklos Szeredi
2010-10-20 2:37 ` Nick Piggin
2010-10-19 3:42 ` [patch 24/35] fs: icache use RCU to avoid locking in hash lookups npiggin
2010-10-19 3:42 ` [patch 25/35] fs: icache reduce some locking overheads npiggin
2010-10-19 3:42 ` [patch 26/35] fs: icache alloc anonymous inode allocation npiggin
2010-10-19 15:50 ` Miklos Szeredi
2010-10-20 2:38 ` Nick Piggin
2010-10-19 16:33 ` Christoph Hellwig
2010-10-20 3:07 ` Nick Piggin
2010-10-19 3:42 ` [patch 27/35] fs: icache split IO and LRU lists npiggin
2010-10-19 16:12 ` Miklos Szeredi
2010-10-20 2:41 ` Nick Piggin
2010-10-19 3:42 ` [patch 28/35] fs: icache split writeback and lru locks npiggin
2010-10-19 3:42 ` [patch 29/35] fs: icache per-bdi writeback list locking npiggin
2010-10-19 3:42 ` [patch 30/35] fs: icache lazy LRU avoid LRU locking after IO operation npiggin
2010-10-19 3:42 ` [patch 31/35] fs: icache per-zone inode LRU npiggin
2010-10-19 12:38 ` Dave Chinner
2010-10-20 2:35 ` Nick Piggin
2010-10-20 3:12 ` Nick Piggin
2010-10-20 9:43 ` Dave Chinner
2010-10-20 10:02 ` Nick Piggin
2010-10-20 3:14 ` KOSAKI Motohiro
2010-10-20 3:20 ` Nick Piggin
2010-10-20 3:29 ` KOSAKI Motohiro
2010-10-20 10:19 ` Dave Chinner
2010-10-20 10:41 ` Nick Piggin
2010-10-19 3:42 ` [patch 32/35] fs: icache minimise I_FREEING latency npiggin
2010-10-19 3:42 ` [patch 33/35] fs: icache introduce inode_get/inode_get_ilock npiggin
2010-10-19 10:17 ` Boaz Harrosh
2010-10-20 2:17 ` Nick Piggin
2010-10-19 3:42 ` [patch 34/35] fs: inode rename i_count to i_refs npiggin
2010-10-19 3:42 ` [patch 35/35] fs: icache document more lock orders npiggin
2010-10-19 16:22 ` [patch 00/35] my inode scaling series for review Christoph Hellwig
2010-10-20 3:05 ` Nick Piggin
2010-10-20 13:14 ` Al Viro
2010-10-20 13:59 ` Nick Piggin
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