From 0bc77381c1b1600e659eb7322c39d1753615722d Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 21 Jun 2013 08:58:21 -0400 Subject: [PATCH] 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 --- fs/seq_file.c | 54 ++++++++++++++++++++++++++++++++++++++++ include/linux/seq_file.h | 6 +++++ 2 files changed, 60 insertions(+) diff --git a/fs/seq_file.c b/fs/seq_file.c index 774c1eb7f1c9..3135c2525c76 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -921,3 +921,57 @@ struct hlist_node *seq_hlist_next_rcu(void *v, return rcu_dereference(node->next); } EXPORT_SYMBOL(seq_hlist_next_rcu); + +/** + * seq_hlist_start_precpu - start an iteration of a percpu hlist array + * @head: pointer to percpu array of struct hlist_heads + * @cpu: pointer to cpu "cursor" + * @pos: start position of sequence + * + * Called at seq_file->op->start(). + */ +struct hlist_node * +seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos) +{ + struct hlist_node *node; + + for_each_possible_cpu(*cpu) { + hlist_for_each(node, per_cpu_ptr(head, *cpu)) { + if (pos-- == 0) + return node; + } + } + return NULL; +} +EXPORT_SYMBOL(seq_hlist_start_percpu); + +/** + * seq_hlist_next_percpu - move to the next position of the percpu hlist array + * @v: pointer to current hlist_node + * @head: pointer to percpu array of struct hlist_heads + * @cpu: pointer to cpu "cursor" + * @pos: start position of sequence + * + * Called at seq_file->op->next(). + */ +struct hlist_node * +seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, + int *cpu, loff_t *pos) +{ + struct hlist_node *node = v; + + ++*pos; + + if (node->next) + return node->next; + + for (*cpu = cpumask_next(*cpu, cpu_possible_mask); *cpu < nr_cpu_ids; + *cpu = cpumask_next(*cpu, cpu_possible_mask)) { + struct hlist_head *bucket = per_cpu_ptr(head, *cpu); + + if (!hlist_empty(bucket)) + return bucket->first; + } + return NULL; +} +EXPORT_SYMBOL(seq_hlist_next_percpu); 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 -- 2.39.5