io-wq: add io_wq_work_node based stack

Apart from just using lists (i.e. io_wq_work_list), we also want to have
stacks, which are a bit faster, and have some interoperability between
them. Add a stack implementation based on io_wq_work_node and some
helpers.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5d3a412a5ac0d47e0f0499d70d2207d70a68925e.1632516769.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2021-09-24 21:59:46 +01:00 committed by Jens Axboe
parent 3ab665b74e
commit 0d9521b9b5

View file

@ -29,6 +29,15 @@ struct io_wq_work_list {
struct io_wq_work_node *last;
};
#define wq_list_for_each(pos, prv, head) \
for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
#define wq_list_empty(list) (READ_ONCE((list)->first) == NULL)
#define INIT_WQ_LIST(list) do { \
(list)->first = NULL; \
(list)->last = NULL; \
} while (0)
static inline void wq_list_add_after(struct io_wq_work_node *node,
struct io_wq_work_node *pos,
struct io_wq_work_list *list)
@ -54,6 +63,15 @@ static inline void wq_list_add_tail(struct io_wq_work_node *node,
}
}
static inline void wq_list_add_head(struct io_wq_work_node *node,
struct io_wq_work_list *list)
{
node->next = list->first;
if (!node->next)
list->last = node;
WRITE_ONCE(list->first, node);
}
static inline void wq_list_cut(struct io_wq_work_list *list,
struct io_wq_work_node *last,
struct io_wq_work_node *prev)
@ -69,6 +87,31 @@ static inline void wq_list_cut(struct io_wq_work_list *list,
last->next = NULL;
}
static inline void __wq_list_splice(struct io_wq_work_list *list,
struct io_wq_work_node *to)
{
list->last->next = to->next;
to->next = list->first;
INIT_WQ_LIST(list);
}
static inline bool wq_list_splice(struct io_wq_work_list *list,
struct io_wq_work_node *to)
{
if (!wq_list_empty(list)) {
__wq_list_splice(list, to);
return true;
}
return false;
}
static inline void wq_stack_add_head(struct io_wq_work_node *node,
struct io_wq_work_node *stack)
{
node->next = stack->next;
stack->next = node;
}
static inline void wq_list_del(struct io_wq_work_list *list,
struct io_wq_work_node *node,
struct io_wq_work_node *prev)
@ -76,14 +119,14 @@ static inline void wq_list_del(struct io_wq_work_list *list,
wq_list_cut(list, node, prev);
}
#define wq_list_for_each(pos, prv, head) \
for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
static inline
struct io_wq_work_node *wq_stack_extract(struct io_wq_work_node *stack)
{
struct io_wq_work_node *node = stack->next;
#define wq_list_empty(list) (READ_ONCE((list)->first) == NULL)
#define INIT_WQ_LIST(list) do { \
(list)->first = NULL; \
(list)->last = NULL; \
} while (0)
stack->next = node->next;
return node;
}
struct io_wq_work {
struct io_wq_work_node list;