[patch 13/14] fs: icache split IO and LRU lists
From: npiggin
Date: Thu Oct 21 2010 - 09:24:46 EST
Split inode reclaim and writeback lists in preparation to scale them up
(per-bdi locking for i_io and per-zone locking for i_lru)
Signed-off-by: Nick Piggin <npiggin@xxxxxxxxx>
---
fs/fs-writeback.c | 27 ++++++-------
fs/inode.c | 91 +++++++++++++++++++++++++++-------------------
fs/internal.h | 2 -
fs/nilfs2/mdt.c | 3 +
include/linux/fs.h | 3 +
include/linux/writeback.h | 1
mm/backing-dev.c | 6 +--
7 files changed, 74 insertions(+), 59 deletions(-)
Index: linux-2.6/fs/fs-writeback.c
===================================================================
--- linux-2.6.orig/fs/fs-writeback.c 2010-10-21 23:50:27.000000000 +1100
+++ linux-2.6/fs/fs-writeback.c 2010-10-21 23:50:27.000000000 +1100
@@ -173,11 +173,11 @@ static void redirty_tail(struct inode *i
if (!list_empty(&wb->b_dirty)) {
struct inode *tail;
- tail = list_entry(wb->b_dirty.next, struct inode, i_list);
+ tail = list_entry(wb->b_dirty.next, struct inode, i_io);
if (time_before(inode->dirtied_when, tail->dirtied_when))
inode->dirtied_when = jiffies;
}
- list_move(&inode->i_list, &wb->b_dirty);
+ list_move(&inode->i_io, &wb->b_dirty);
}
/*
@@ -188,7 +188,7 @@ static void requeue_io(struct inode *ino
struct bdi_writeback *wb = &inode_to_bdi(inode)->wb;
assert_spin_locked(&wb_inode_list_lock);
- list_move(&inode->i_list, &wb->b_more_io);
+ list_move(&inode->i_io, &wb->b_more_io);
}
static void inode_sync_complete(struct inode *inode)
@@ -230,14 +230,14 @@ static void move_expired_inodes(struct l
assert_spin_locked(&wb_inode_list_lock);
while (!list_empty(delaying_queue)) {
- inode = list_entry(delaying_queue->prev, struct inode, i_list);
+ inode = list_entry(delaying_queue->prev, struct inode, i_io);
if (older_than_this &&
inode_dirtied_after(inode, *older_than_this))
break;
if (sb && sb != inode->i_sb)
do_sb_sort = 1;
sb = inode->i_sb;
- list_move(&inode->i_list, &tmp);
+ list_move(&inode->i_io, &tmp);
}
/* just one sb in list, splice to dispatch_queue and we're done */
@@ -248,12 +248,12 @@ static void move_expired_inodes(struct l
/* Move inodes from one superblock together */
while (!list_empty(&tmp)) {
- inode = list_entry(tmp.prev, struct inode, i_list);
+ inode = list_entry(tmp.prev, struct inode, i_io);
sb = inode->i_sb;
list_for_each_prev_safe(pos, node, &tmp) {
- inode = list_entry(pos, struct inode, i_list);
+ inode = list_entry(pos, struct inode, i_io);
if (inode->i_sb == sb)
- list_move(&inode->i_list, dispatch_queue);
+ list_move(&inode->i_io, dispatch_queue);
}
}
}
@@ -420,8 +420,7 @@ writeback_single_inode(struct inode *ino
/*
* The inode is clean
*/
- list_move(&inode->i_list, &inode_unused);
- atomic_inc(&nr_unused);
+ list_del_init(&inode->i_io);
}
}
inode_sync_complete(inode);
@@ -471,7 +470,7 @@ static int writeback_sb_inodes(struct su
while (!list_empty(&wb->b_io)) {
long pages_skipped;
struct inode *inode = list_entry(wb->b_io.prev,
- struct inode, i_list);
+ struct inode, i_io);
if (!spin_trylock(&inode->i_lock)) {
spin_unlock(&wb_inode_list_lock);
@@ -558,7 +557,7 @@ void writeback_inodes_wb(struct bdi_writ
while (!list_empty(&wb->b_io)) {
struct inode *inode = list_entry(wb->b_io.prev,
- struct inode, i_list);
+ struct inode, i_io);
struct super_block *sb = inode->i_sb;
if (!pin_sb_for_writeback(sb)) {
@@ -704,7 +703,7 @@ static long wb_writeback(struct bdi_writ
spin_lock(&wb_inode_list_lock);
if (!list_empty(&wb->b_more_io)) {
inode = list_entry(wb->b_more_io.prev,
- struct inode, i_list);
+ struct inode, i_io);
if (!spin_trylock(&inode->i_lock)) {
spin_unlock(&wb_inode_list_lock);
cpu_relax();
@@ -1025,7 +1024,7 @@ void __mark_inode_dirty(struct inode *in
inode->dirtied_when = jiffies;
spin_lock(&wb_inode_list_lock);
- list_move(&inode->i_list, &bdi->wb.b_dirty);
+ list_move(&inode->i_io, &bdi->wb.b_dirty);
spin_unlock(&wb_inode_list_lock);
}
}
Index: linux-2.6/include/linux/fs.h
===================================================================
--- linux-2.6.orig/include/linux/fs.h 2010-10-21 23:50:27.000000000 +1100
+++ linux-2.6/include/linux/fs.h 2010-10-21 23:50:27.000000000 +1100
@@ -725,7 +725,8 @@ struct posix_acl;
struct inode {
struct hlist_node i_hash;
- struct list_head i_list; /* backing dev IO list */
+ struct list_head i_io; /* backing dev IO list */
+ struct list_head i_lru; /* inode LRU list */
struct list_head i_sb_list;
struct list_head i_dentry;
unsigned long i_ino;
Index: linux-2.6/mm/backing-dev.c
===================================================================
--- linux-2.6.orig/mm/backing-dev.c 2010-10-21 23:50:27.000000000 +1100
+++ linux-2.6/mm/backing-dev.c 2010-10-21 23:50:27.000000000 +1100
@@ -74,11 +74,11 @@ static int bdi_debug_stats_show(struct s
nr_wb = nr_dirty = nr_io = nr_more_io = 0;
spin_lock(&wb_inode_list_lock);
- list_for_each_entry(inode, &wb->b_dirty, i_list)
+ list_for_each_entry(inode, &wb->b_dirty, i_io)
nr_dirty++;
- list_for_each_entry(inode, &wb->b_io, i_list)
+ list_for_each_entry(inode, &wb->b_io, i_io)
nr_io++;
- list_for_each_entry(inode, &wb->b_more_io, i_list)
+ list_for_each_entry(inode, &wb->b_more_io, i_io)
nr_more_io++;
spin_unlock(&wb_inode_list_lock);
Index: linux-2.6/fs/inode.c
===================================================================
--- linux-2.6.orig/fs/inode.c 2010-10-21 23:50:27.000000000 +1100
+++ linux-2.6/fs/inode.c 2010-10-21 23:50:38.000000000 +1100
@@ -33,14 +33,15 @@
* i_count
* i_state
* i_hash
- * i_list
+ * i_lru
+ * i_io
* i_sb_list
* sb_inode_list_lock protects:
* s_inodes, i_sb_list
* inode_hash_lock protects:
* inode hash table, i_hash
* wb_inode_list_lock protects:
- * inode_unused, b_io, b_more_io, b_dirty, i_list
+ * inode_lru, b_io, b_more_io, b_dirty, i_lru, i_io
*
* Ordering:
* i_lock
@@ -95,7 +96,7 @@ static unsigned int i_hash_shift __read_
* allowing for low-overhead inode sync() operations.
*/
-LIST_HEAD(inode_unused);
+static LIST_HEAD(inode_lru);
static struct hlist_head *inode_hashtable __read_mostly;
/*
@@ -298,6 +299,7 @@ EXPORT_SYMBOL(__destroy_inode);
void destroy_inode(struct inode *inode)
{
+ BUG_ON(!list_empty(&inode->i_io));
__destroy_inode(inode);
if (inode->i_sb->s_op->destroy_inode)
inode->i_sb->s_op->destroy_inode(inode);
@@ -316,7 +318,8 @@ void inode_init_once(struct inode *inode
INIT_HLIST_NODE(&inode->i_hash);
INIT_LIST_HEAD(&inode->i_dentry);
INIT_LIST_HEAD(&inode->i_devices);
- INIT_LIST_HEAD(&inode->i_list);
+ INIT_LIST_HEAD(&inode->i_io);
+ INIT_LIST_HEAD(&inode->i_lru);
INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC);
spin_lock_init(&inode->i_data.tree_lock);
spin_lock_init(&inode->i_data.i_mmap_lock);
@@ -388,6 +391,35 @@ static void evict(struct inode *inode)
cd_forget(inode);
}
+static void insert_inode_lru(struct inode *inode)
+{
+ if (list_empty(&inode->i_lru)) {
+ spin_lock(&wb_inode_list_lock);
+ list_add(&inode->i_lru, &inode_lru);
+ spin_unlock(&wb_inode_list_lock);
+ atomic_inc(&nr_unused);
+ }
+}
+
+static void remove_inode_lru(struct inode *inode)
+{
+ if (!list_empty(&inode->i_lru)) {
+ spin_lock(&wb_inode_list_lock);
+ list_del_init(&inode->i_lru);
+ spin_unlock(&wb_inode_list_lock);
+ atomic_dec(&nr_unused);
+ }
+}
+
+static void remove_inode_io(struct inode *inode)
+{
+ if (!list_empty(&inode->i_io)) {
+ spin_lock(&wb_inode_list_lock);
+ list_del_init(&inode->i_io);
+ spin_unlock(&wb_inode_list_lock);
+ }
+}
+
static void __remove_inode_hash(struct inode *inode);
/*
@@ -405,8 +437,8 @@ static void dispose_list(struct list_hea
struct inode *inode;
/* No locking here, it's a private list now */
- inode = list_first_entry(head, struct inode, i_list);
- list_del_init(&inode->i_list);
+ inode = list_first_entry(head, struct inode, i_lru);
+ list_del_init(&inode->i_lru);
evict(inode);
@@ -454,17 +486,12 @@ static int invalidate_list(struct super_
}
invalidate_inode_buffers(inode);
if (!inode->i_count) {
- if (!list_empty(&inode->i_list)) {
- spin_lock(&wb_inode_list_lock);
- list_del(&inode->i_list);
- spin_unlock(&wb_inode_list_lock);
- if (!(inode->i_state & (I_DIRTY|I_SYNC)))
- atomic_dec(&nr_unused);
- }
+ remove_inode_lru(inode);
+ remove_inode_io(inode);
WARN_ON(inode->i_state & I_NEW);
inode->i_state |= I_FREEING;
spin_unlock(&inode->i_lock);
- list_add(&inode->i_list, dispose);
+ list_add(&inode->i_lru, dispose);
count++;
continue;
}
@@ -518,7 +545,7 @@ static int can_unuse(struct inode *inode
*
* Any inodes which are pinned purely because of attached pagecache have their
* pagecache removed. We expect the final iput() on that inode to add it to
- * the front of the inode_unused list. So look for it there and if the
+ * the front of the inode_lru list. So look for it there and if the
* inode is still freeable, proceed. The right inode is found 99.9% of the
* time in testing on a 4-way.
*
@@ -538,10 +565,10 @@ static void prune_icache(int nr_to_scan)
for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) {
struct inode *inode;
- if (list_empty(&inode_unused))
+ if (list_empty(&inode_lru))
break;
- inode = list_entry(inode_unused.prev, struct inode, i_list);
+ inode = list_entry(inode_lru.prev, struct inode, i_lru);
if (!spin_trylock(&inode->i_lock)) {
spin_unlock(&wb_inode_list_lock);
@@ -550,13 +577,13 @@ static void prune_icache(int nr_to_scan)
}
if (inode->i_count || (inode->i_state & ~I_REFERENCED)) {
- list_del_init(&inode->i_list);
+ list_del_init(&inode->i_lru);
spin_unlock(&inode->i_lock);
atomic_dec(&nr_unused);
continue;
}
if (inode->i_state & I_REFERENCED) {
- list_move(&inode->i_list, &inode_unused);
+ list_move(&inode->i_lru, &inode_lru);
inode->i_state &= ~I_REFERENCED;
spin_unlock(&inode->i_lock);
continue;
@@ -569,7 +596,7 @@ static void prune_icache(int nr_to_scan)
*
* We'll try to get it back if it becomes freeable.
*/
- list_move(&inode->i_list, &inode_unused);
+ list_move(&inode->i_lru, &inode_lru);
inode->i_count++;
spin_unlock(&wb_inode_list_lock);
spin_unlock(&inode->i_lock);
@@ -585,8 +612,8 @@ static void prune_icache(int nr_to_scan)
goto lock_again_2;
}
- if (inode != list_entry(inode_unused.next,
- struct inode, i_list)) {
+ if (inode != list_entry(inode_lru.next,
+ struct inode, i_lru)) {
spin_unlock(&inode->i_lock);
continue; /* wrong inode or list_empty */
}
@@ -595,7 +622,7 @@ static void prune_icache(int nr_to_scan)
continue;
}
}
- list_move(&inode->i_list, &freeable);
+ list_move(&inode->i_lru, &freeable);
WARN_ON(inode->i_state & I_NEW);
inode->i_state |= I_FREEING;
spin_unlock(&inode->i_lock);
@@ -1420,13 +1447,8 @@ static void iput_final(struct inode *ino
if (!drop) {
if (sb->s_flags & MS_ACTIVE) {
inode->i_state |= I_REFERENCED;
- if (!(inode->i_state & (I_DIRTY|I_SYNC)) &&
- list_empty(&inode->i_list)) {
- spin_lock(&wb_inode_list_lock);
- list_add(&inode->i_list, &inode_unused);
- spin_unlock(&wb_inode_list_lock);
- atomic_inc(&nr_unused);
- }
+ if (!(inode->i_state & (I_DIRTY|I_SYNC)))
+ insert_inode_lru(inode);
spin_unlock(&inode->i_lock);
return;
}
@@ -1439,13 +1461,8 @@ static void iput_final(struct inode *ino
inode->i_state &= ~I_WILL_FREE;
__remove_inode_hash(inode);
}
- if (!list_empty(&inode->i_list)) {
- spin_lock(&wb_inode_list_lock);
- list_del_init(&inode->i_list);
- spin_unlock(&wb_inode_list_lock);
- if (!(inode->i_state & (I_DIRTY|I_SYNC)))
- atomic_dec(&nr_unused);
- }
+ remove_inode_lru(inode);
+ remove_inode_io(inode);
spin_lock(&sb_inode_list_lock);
list_del_init(&inode->i_sb_list);
spin_unlock(&sb_inode_list_lock);
Index: linux-2.6/fs/nilfs2/mdt.c
===================================================================
--- linux-2.6.orig/fs/nilfs2/mdt.c 2010-10-21 23:50:27.000000000 +1100
+++ linux-2.6/fs/nilfs2/mdt.c 2010-10-21 23:50:27.000000000 +1100
@@ -504,7 +504,8 @@ nilfs_mdt_new_common(struct the_nilfs *n
#endif
inode->dirtied_when = 0;
- INIT_LIST_HEAD(&inode->i_list);
+ INIT_LIST_HEAD(&inode->i_io);
+ INIT_LIST_HEAD(&inode->i_lru);
INIT_LIST_HEAD(&inode->i_sb_list);
inode->i_state = 0;
#endif
Index: linux-2.6/fs/internal.h
===================================================================
--- linux-2.6.orig/fs/internal.h 2010-10-21 23:50:27.000000000 +1100
+++ linux-2.6/fs/internal.h 2010-10-21 23:50:27.000000000 +1100
@@ -45,8 +45,6 @@ static inline int __sync_blockdev(struct
}
#endif
-extern atomic_t nr_unused;
-
/*
* char_dev.c
*/
Index: linux-2.6/include/linux/writeback.h
===================================================================
--- linux-2.6.orig/include/linux/writeback.h 2010-10-21 23:50:27.000000000 +1100
+++ linux-2.6/include/linux/writeback.h 2010-10-21 23:50:27.000000000 +1100
@@ -11,7 +11,6 @@ struct backing_dev_info;
extern spinlock_t sb_inode_list_lock;
extern spinlock_t wb_inode_list_lock;
-extern struct list_head inode_unused;
/*
* fs/fs-writeback.c
--
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