io_uring: add support for hybrid IOPOLL

A new hybrid poll is implemented on the io_uring layer. Once an IO is
issued, it will not poll immediately, but rather block first and re-run
before IO complete, then poll to reap IO. While this poll method could
be a suboptimal solution when running on a single thread, it offers
performance lower than regular polling but higher than IRQ, and CPU
utilization is also lower than polling.

To use hybrid polling, the ring must be setup with both the
IORING_SETUP_IOPOLL and IORING_SETUP_HYBRID)IOPOLL flags set. Hybrid
polling has the same restrictions as IOPOLL, in that commands must
explicitly support it.

Signed-off-by: hexue <xue01.he@samsung.com>
Link: https://lore.kernel.org/r/20241101091957.564220-2-xue01.he@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This commit is contained in:

hexue

2024-11-01 17:19:57 +08:00

committed by

Jens Axboe

parent c1329532d5

commit 01ee194d1a

4 changed files with 108 additions and 14 deletions

									
										include/uapi/linux/io_uring.h
									
		+3
		
												View File
												
				@@ -200,6 +200,9 @@ enum io_uring_sqe_flags_bit {

				 */

				#define IORING_SETUP_NO_SQARRAY		(1U << 16)

				/* Use hybrid poll in iopoll process */

				#define IORING_SETUP_HYBRID_IOPOLL	(1U << 17)

				enum io_uring_op {

					IORING_OP_NOP,

					IORING_OP_READV,