io_wq: add per-wq work handler instead of per work

io_uring is the only user of io-wq, and now it uses only io-wq callback
for all its requests, namely io_wq_submit_work(). Instead of storing
work->runner callback in each instance of io_wq_work, keep it in io-wq
itself.

pros:
- reduces io_wq_work size
- more robust -- ->func won't be invalidated with mem{cpy,set}(req)
- helps other work

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2020-06-08 21:08:20 +03:00 committed by Jens Axboe
parent d4c81f3852
commit f5fa38c59c
3 changed files with 12 additions and 8 deletions

View File

@ -112,6 +112,7 @@ struct io_wq {
unsigned long state;
free_work_fn *free_work;
io_wq_work_fn *do_work;
struct task_struct *manager;
struct user_struct *user;
@ -528,7 +529,7 @@ static void io_worker_handle_work(struct io_worker *worker)
hash = io_get_work_hash(work);
linked = old_work = work;
linked->func(&linked);
wq->do_work(&linked);
linked = (old_work == linked) ? NULL : linked;
work = next_hashed;
@ -785,7 +786,7 @@ static void io_run_cancel(struct io_wq_work *work, struct io_wqe *wqe)
struct io_wq_work *old_work = work;
work->flags |= IO_WQ_WORK_CANCEL;
work->func(&work);
wq->do_work(&work);
work = (work == old_work) ? NULL : work;
wq->free_work(old_work);
} while (work);
@ -1023,7 +1024,7 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
int ret = -ENOMEM, node;
struct io_wq *wq;
if (WARN_ON_ONCE(!data->free_work))
if (WARN_ON_ONCE(!data->free_work || !data->do_work))
return ERR_PTR(-EINVAL);
wq = kzalloc(sizeof(*wq), GFP_KERNEL);
@ -1037,6 +1038,7 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
}
wq->free_work = data->free_work;
wq->do_work = data->do_work;
/* caller must already hold a reference to this */
wq->user = data->user;
@ -1093,7 +1095,7 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
bool io_wq_get(struct io_wq *wq, struct io_wq_data *data)
{
if (data->free_work != wq->free_work)
if (data->free_work != wq->free_work || data->do_work != wq->do_work)
return false;
return refcount_inc_not_zero(&wq->use_refs);

View File

@ -85,7 +85,6 @@ static inline void wq_list_del(struct io_wq_work_list *list,
struct io_wq_work {
struct io_wq_work_node list;
void (*func)(struct io_wq_work **);
struct files_struct *files;
struct mm_struct *mm;
const struct cred *creds;
@ -94,9 +93,9 @@ struct io_wq_work {
pid_t task_pid;
};
#define INIT_IO_WORK(work, _func) \
#define INIT_IO_WORK(work) \
do { \
*(work) = (struct io_wq_work){ .func = _func }; \
*(work) = (struct io_wq_work){}; \
} while (0) \
static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
@ -108,10 +107,12 @@ static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
}
typedef void (free_work_fn)(struct io_wq_work *);
typedef void (io_wq_work_fn)(struct io_wq_work **);
struct io_wq_data {
struct user_struct *user;
io_wq_work_fn *do_work;
free_work_fn *free_work;
};

View File

@ -5776,7 +5776,7 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
refcount_set(&req->refs, 2);
req->task = NULL;
req->result = 0;
INIT_IO_WORK(&req->work, io_wq_submit_work);
INIT_IO_WORK(&req->work);
if (unlikely(req->opcode >= IORING_OP_LAST))
return -EINVAL;
@ -6796,6 +6796,7 @@ static int io_init_wq_offload(struct io_ring_ctx *ctx,
data.user = ctx->user;
data.free_work = io_free_work;
data.do_work = io_wq_submit_work;
if (!(p->flags & IORING_SETUP_ATTACH_WQ)) {
/* Do QD, or 4 * CPUS, whatever is smallest */