From 84d08fa888e7c2d53b5bbc764db2ef02968b499c Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 5 Jul 2013 18:59:33 +0400 Subject: helper for reading ->d_count Signed-off-by: Al Viro --- include/linux/dcache.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux') diff --git a/include/linux/dcache.h b/include/linux/dcache.h index f42dbe145479..3092df3614ae 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -324,6 +324,11 @@ static inline int __d_rcu_to_refcount(struct dentry *dentry, unsigned seq) return ret; } +static inline unsigned d_count(struct dentry *dentry) +{ + return dentry->d_count; +} + /* validate "insecure" dentry pointer */ extern int d_validate(struct dentry *, struct dentry *); -- cgit v1.2.3 From 0bc77381c1b1600e659eb7322c39d1753615722d Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 21 Jun 2013 08:58:21 -0400 Subject: seq_file: add seq_list_*_percpu helpers When we convert the file_lock_list to a set of percpu lists, we'll need a way to iterate over them in order to output /proc/locks info. Add some seq_list_*_percpu helpers to handle that. Signed-off-by: Jeff Layton Acked-by: J. Bruce Fields Signed-off-by: Al Viro --- include/linux/seq_file.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux') diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h index 2da29ac178fc..4e32edc8f506 100644 --- a/include/linux/seq_file.h +++ b/include/linux/seq_file.h @@ -173,4 +173,10 @@ extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, extern struct hlist_node *seq_hlist_next_rcu(void *v, struct hlist_head *head, loff_t *ppos); + +/* Helpers for iterating over per-cpu hlist_head-s in seq_files */ +extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos); + +extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos); + #endif -- cgit v1.2.3 From 7012b02a2b2c42bb1e1d95040a6e3bb59c7284f7 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 21 Jun 2013 08:58:22 -0400 Subject: locks: move file_lock_list to a set of percpu hlist_heads and convert file_lock_lock to an lglock The file_lock_list is only used for /proc/locks. The vastly common case is for locks to be put onto the list and come off again, without ever being traversed. Help optimize for this use-case by moving to percpu hlist_head-s. At the same time, we can make the locking less contentious by moving to an lglock. When iterating over the lists for /proc/locks, we must take the global lock and then iterate over each CPU's list in turn. This change necessitates a new fl_link_cpu field to keep track of which CPU the entry is on. On x86_64 at least, this field is placed within an existing hole in the struct to avoid growing the size. Signed-off-by: Jeff Layton Acked-by: J. Bruce Fields Signed-off-by: Al Viro --- include/linux/fs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/fs.h b/include/linux/fs.h index 99be011e00de..834c9e5113d9 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -954,6 +954,7 @@ struct file_lock { unsigned int fl_flags; unsigned char fl_type; unsigned int fl_pid; + int fl_link_cpu; /* what cpu's list is this on? */ struct pid *fl_nspid; wait_queue_head_t fl_wait; struct file *fl_file; -- cgit v1.2.3