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io_uring/kbuf: cleanup passing back cflags 

We have various functions calculating the CQE cflags we need to pass
back, but it's all the same everywhere. Make a number of the putting
functions void, and just have the two main helps for this, io_put_kbuf()
and io_put_kbuf_comp() calculate the actual mask and pass it back.

While at it, cleanup how we put REQ_F_BUFFER_RING buffers. Before
this change, we would call into __io_put_kbuf() only to go right back
in to the header defined functions. As clearing this type of buffer
is just re-assigning the buf_index and incrementing the head, this
is very wasteful.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2024-01-29 20:59:18 -07:00
parent 949249e25f
commit 8435c6f380
2 changed files with 31 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
io_uring/kbuf.c
View File

@ -102,10 +102,8 @@ bool io_kbuf_recycle_legacy(struct io_kiocb *req, unsigned issue_flags)
return true;
}
unsigned int __io_put_kbuf(struct io_kiocb *req, unsigned issue_flags)
void __io_put_kbuf(struct io_kiocb *req, unsigned issue_flags)
{
unsigned int cflags;
/*
* We can add this buffer back to two lists:
*
@ -118,21 +116,17 @@ unsigned int __io_put_kbuf(struct io_kiocb *req, unsigned issue_flags)
* We migrate buffers from the comp_list to the issue cache list
* when we need one.
*/
if (req->flags & REQ_F_BUFFER_RING) {
/* no buffers to recycle for this case */
cflags = __io_put_kbuf_list(req, NULL);
} else if (issue_flags & IO_URING_F_UNLOCKED) {
if (issue_flags & IO_URING_F_UNLOCKED) {
struct io_ring_ctx *ctx = req->ctx;
spin_lock(&ctx->completion_lock);
cflags = __io_put_kbuf_list(req, &ctx->io_buffers_comp);
__io_put_kbuf_list(req, &ctx->io_buffers_comp);
spin_unlock(&ctx->completion_lock);
} else {
lockdep_assert_held(&req->ctx->uring_lock);
cflags = __io_put_kbuf_list(req, &req->ctx->io_buffers_cache);
__io_put_kbuf_list(req, &req->ctx->io_buffers_cache);
}
return cflags;
}
static void __user *io_provided_buffer_select(struct io_kiocb *req, size_t *len,

41
io_uring/kbuf.h
View File

@ -57,7 +57,7 @@ int io_register_pbuf_status(struct io_ring_ctx *ctx, void __user *arg);
void io_kbuf_mmap_list_free(struct io_ring_ctx *ctx);
unsigned int __io_put_kbuf(struct io_kiocb *req, unsigned issue_flags);
void __io_put_kbuf(struct io_kiocb *req, unsigned issue_flags);
bool io_kbuf_recycle_legacy(struct io_kiocb *req, unsigned issue_flags);
@ -108,41 +108,54 @@ static inline bool io_kbuf_recycle(struct io_kiocb *req, unsigned issue_flags)
return false;
}
static inline unsigned int __io_put_kbuf_list(struct io_kiocb *req,
struct list_head *list)
static inline void __io_put_kbuf_ring(struct io_kiocb *req)
{
unsigned int ret = IORING_CQE_F_BUFFER | (req->buf_index << IORING_CQE_BUFFER_SHIFT);
if (req->buf_list) {
req->buf_index = req->buf_list->bgid;
req->buf_list->head++;
}
req->flags &= ~REQ_F_BUFFER_RING;
}
static inline void __io_put_kbuf_list(struct io_kiocb *req,
struct list_head *list)
{
if (req->flags & REQ_F_BUFFER_RING) {
if (req->buf_list) {
req->buf_index = req->buf_list->bgid;
req->buf_list->head++;
}
req->flags &= ~REQ_F_BUFFER_RING;
__io_put_kbuf_ring(req);
} else {
req->buf_index = req->kbuf->bgid;
list_add(&req->kbuf->list, list);
req->flags &= ~REQ_F_BUFFER_SELECTED;
}
return ret;
}
static inline unsigned int io_put_kbuf_comp(struct io_kiocb *req)
{
unsigned int ret;
lockdep_assert_held(&req->ctx->completion_lock);
if (!(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)))
return 0;
return __io_put_kbuf_list(req, &req->ctx->io_buffers_comp);
ret = IORING_CQE_F_BUFFER | (req->buf_index << IORING_CQE_BUFFER_SHIFT);
__io_put_kbuf_list(req, &req->ctx->io_buffers_comp);
return ret;
}
static inline unsigned int io_put_kbuf(struct io_kiocb *req,
unsigned issue_flags)
{
unsigned int ret;
if (!(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)))
if (!(req->flags & (REQ_F_BUFFER_RING | REQ_F_BUFFER_SELECTED)))
return 0;
return __io_put_kbuf(req, issue_flags);
ret = IORING_CQE_F_BUFFER | (req->buf_index << IORING_CQE_BUFFER_SHIFT);
if (req->flags & REQ_F_BUFFER_RING)
__io_put_kbuf_ring(req);
else
__io_put_kbuf(req, issue_flags);
return ret;
}
#endif