If user doesn't configured poll queue but do the polled IO, it will get
a low performeance than regular poll, but 100% CPU uage. And there's no
prompts or warnings.
This patch aims to help users more easily verify their configurations
correctly, avoiding time and performance losses.
--
changes from v1:
- without disrupting the original I/O process.
- move judgement from block to io_uring.
Signed-off-by: hexue <xue01.he@xxxxxxxxxxx>
---
include/linux/io_uring_types.h | 1 +
io_uring/io_uring.c | 4 +++-
io_uring/rw.c | 18 ++++++++++++++++++
3 files changed, 22 insertions(+), 1 deletion(-)
diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index 91224bbcfa73..270c3edbbf21 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -428,6 +428,7 @@ struct io_ring_ctx {
unsigned short n_sqe_pages;
struct page **ring_pages;
struct page **sqe_pages;
+ bool check_poll_queue;
};
struct io_tw_state {
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 816e93e7f949..1b45b4c52ae0 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -3463,8 +3463,10 @@ static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
!(ctx->flags & IORING_SETUP_SQPOLL))
ctx->task_complete = true;
- if (ctx->task_complete || (ctx->flags & IORING_SETUP_IOPOLL))
+ if (ctx->task_complete || (ctx->flags & IORING_SETUP_IOPOLL)) {
ctx->lockless_cq = true;
+ ctx->check_poll_queue = false;
+ }
/*
* lazy poll_wq activation relies on ->task_complete for synchronisation
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 1a2128459cb4..20f417152a17 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -772,6 +772,23 @@ static bool need_complete_io(struct io_kiocb *req)
S_ISBLK(file_inode(req->file)->i_mode);
}
+static void check_poll_queue_state(struct io_ring_ctx *ctx, struct io_kiocb *req)
+{
+ if (!ctx->check_poll_queue) {
+ struct block_device *bdev;
+ struct request_queue *q;
+ struct inode *inode = req->file->f_inode;
+
+ if (inode->i_rdev) {
+ bdev = blkdev_get_no_open(inode->i_rdev);
+ q = bdev->bd_queue;
+ if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
+ pr_warn("the device does't configured with poll queues\n");
+ }
+ ctx->check_poll_queue = true;
+ }
+}
+
static int io_rw_init_file(struct io_kiocb *req, fmode_t mode)
{
struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);
@@ -804,6 +821,7 @@ static int io_rw_init_file(struct io_kiocb *req, fmode_t mode)
if (ctx->flags & IORING_SETUP_IOPOLL) {
if (!(kiocb->ki_flags & IOCB_DIRECT) || !file->f_op->iopoll)
return -EOPNOTSUPP;
+ check_poll_queue_state(ctx, req);
kiocb->private = NULL;
kiocb->ki_flags |= IOCB_HIPRI;
--
2.40.1
