Avoids cache line ping pongs between cpus and prepare next patch, because updates of nr_inodes dont need inode_lock anymore.
(socket8 bench result : no difference at this point) Signed-off-by: Eric Dumazet <[email protected]> --- fs/fs-writeback.c | 2 +- fs/inode.c | 39 +++++++++++++++++++++++++++++++-------- include/linux/fs.h | 3 +++ kernel/sysctl.c | 4 ++-- mm/page-writeback.c | 2 +- 5 files changed, 38 insertions(+), 12 deletions(-) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index d0ff0b8..b591cdd 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -608,7 +608,7 @@ void sync_inodes_sb(struct super_block *sb, int wait) unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS); wbc.nr_to_write = nr_dirty + nr_unstable + - (inodes_stat.nr_inodes - inodes_stat.nr_unused) + + (get_nr_inodes() - inodes_stat.nr_unused) + nr_dirty + nr_unstable; wbc.nr_to_write += wbc.nr_to_write / 2; /* Bit more for luck */ sync_sb_inodes(sb, &wbc); diff --git a/fs/inode.c b/fs/inode.c index 0487ddb..f94f889 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -96,9 +96,33 @@ static DEFINE_MUTEX(iprune_mutex); * Statistics gathering.. */ struct inodes_stat_t inodes_stat; +static struct percpu_counter nr_inodes; static struct kmem_cache * inode_cachep __read_mostly; +int get_nr_inodes(void) +{ + return percpu_counter_sum_positive(&nr_inodes); +} + +/* + * Handle nr_dentry sysctl + */ +#if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS) +int proc_nr_inodes(ctl_table *table, int write, struct file *filp, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + inodes_stat.nr_inodes = get_nr_inodes(); + return proc_dointvec(table, write, filp, buffer, lenp, ppos); +} +#else +int proc_nr_inodes(ctl_table *table, int write, struct file *filp, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + return -ENOSYS; +} +#endif + static void wake_up_inode(struct inode *inode) { /* @@ -306,9 +330,7 @@ static void dispose_list(struct list_head *head) destroy_inode(inode); nr_disposed++; } - spin_lock(&inode_lock); - inodes_stat.nr_inodes -= nr_disposed; - spin_unlock(&inode_lock); + percpu_counter_sub(&nr_inodes, nr_disposed); } /* @@ -560,8 +582,8 @@ struct inode *new_inode(struct super_block *sb) inode = alloc_inode(sb); if (inode) { + percpu_counter_inc(&nr_inodes); spin_lock(&inode_lock); - inodes_stat.nr_inodes++; list_add(&inode->i_list, &inode_in_use); list_add(&inode->i_sb_list, &sb->s_inodes); inode->i_ino = ++last_ino; @@ -622,7 +644,7 @@ static struct inode * get_new_inode(struct super_block *sb, struct hlist_head *h if (set(inode, data)) goto set_failed; - inodes_stat.nr_inodes++; + percpu_counter_inc(&nr_inodes); list_add(&inode->i_list, &inode_in_use); list_add(&inode->i_sb_list, &sb->s_inodes); hlist_add_head(&inode->i_hash, head); @@ -671,7 +693,7 @@ static struct inode * get_new_inode_fast(struct super_block *sb, struct hlist_he old = find_inode_fast(sb, head, ino); if (!old) { inode->i_ino = ino; - inodes_stat.nr_inodes++; + percpu_counter_inc(&nr_inodes); list_add(&inode->i_list, &inode_in_use); list_add(&inode->i_sb_list, &sb->s_inodes); hlist_add_head(&inode->i_hash, head); @@ -1042,8 +1064,8 @@ void generic_delete_inode(struct inode *inode) list_del_init(&inode->i_list); list_del_init(&inode->i_sb_list); inode->i_state |= I_FREEING; - inodes_stat.nr_inodes--; spin_unlock(&inode_lock); + percpu_counter_dec(&nr_inodes); security_inode_delete(inode); @@ -1093,8 +1115,8 @@ static void generic_forget_inode(struct inode *inode) list_del_init(&inode->i_list); list_del_init(&inode->i_sb_list); inode->i_state |= I_FREEING; - inodes_stat.nr_inodes--; spin_unlock(&inode_lock); + percpu_counter_dec(&nr_inodes); if (inode->i_data.nrpages) truncate_inode_pages(&inode->i_data, 0); clear_inode(inode); @@ -1394,6 +1416,7 @@ void __init inode_init(void) { int loop; + percpu_counter_init(&nr_inodes, 0); /* inode slab cache */ inode_cachep = kmem_cache_create("inode_cache", sizeof(struct inode), diff --git a/include/linux/fs.h b/include/linux/fs.h index 114cb65..a789346 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -47,6 +47,7 @@ struct inodes_stat_t { int dummy[5]; /* padding for sysctl ABI compatibility */ }; extern struct inodes_stat_t inodes_stat; +extern int get_nr_inodes(void); extern int leases_enable, lease_break_time; @@ -2219,6 +2220,8 @@ int proc_nr_files(struct ctl_table *table, int write, struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos); int proc_nr_dentry(struct ctl_table *table, int write, struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos); +int proc_nr_inodes(struct ctl_table *table, int write, struct file *filp, + void __user *buffer, size_t *lenp, loff_t *ppos); int get_filesystem_list(char * buf); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 777bee7..b705f3a 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1205,7 +1205,7 @@ static struct ctl_table fs_table[] = { .data = &inodes_stat, .maxlen = 2*sizeof(int), .mode = 0444, - .proc_handler = &proc_dointvec, + .proc_handler = &proc_nr_inodes, }, { .ctl_name = FS_STATINODE, @@ -1213,7 +1213,7 @@ static struct ctl_table fs_table[] = { .data = &inodes_stat, .maxlen = 7*sizeof(int), .mode = 0444, - .proc_handler = &proc_dointvec, + .proc_handler = &proc_nr_inodes, }, { .procname = "file-nr", diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 2970e35..a71a922 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -705,7 +705,7 @@ static void wb_kupdate(unsigned long arg) next_jif = start_jif + dirty_writeback_interval; nr_to_write = global_page_state(NR_FILE_DIRTY) + global_page_state(NR_UNSTABLE_NFS) + - (inodes_stat.nr_inodes - inodes_stat.nr_unused); + (get_nr_inodes() - inodes_stat.nr_unused); while (nr_to_write > 0) { wbc.more_io = 0; wbc.encountered_congestion = 0; -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
