Commit 2b8e976b authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: user registered clockid for wait timeouts 



Add a new registration opcode IORING_REGISTER_CLOCK, which allows the
user to select which clock id it wants to use with CQ waiting timeouts.
It only allows a subset of all posix clocks and currently supports
CLOCK_MONOTONIC and CLOCK_BOOTTIME.

Suggested-by: default avatarLewis Baker <lewissbaker@gmail.com>
Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/98f2bc8a3c36cdf8f0e6a275245e81e903459703.1723039801.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent d29cb372

include/linux/io_uring_types.h

+3 −0
Original line number Diff line number Diff line
@@ -239,6 +239,9 @@ struct io_ring_ctx { 
		struct io_rings		*rings;

		struct percpu_ref	refs;



		clockid_t		clockid;

		enum tk_offsets		clock_offset;



		enum task_work_notify_mode	notify_method;

		unsigned			sq_thread_idle;

	} ____cacheline_aligned_in_smp;

include/uapi/linux/io_uring.h

+7 −0
Original line number Diff line number Diff line
@@ -596,6 +596,8 @@ enum io_uring_register_op { 
	IORING_REGISTER_NAPI			= 27,

	IORING_UNREGISTER_NAPI			= 28,



	IORING_REGISTER_CLOCK			= 29,



	/* this goes last */

	IORING_REGISTER_LAST,
@@ -676,6 +678,11 @@ struct io_uring_restriction { 
	__u32 resv2[3];

};



struct io_uring_clock_register {

	__u32	clockid;

	__u32	__resv[3];

};



struct io_uring_buf {

	__u64	addr;

	__u32	len;

io_uring/io_uring.c

+6 −2
Original line number Diff line number Diff line
@@ -2377,7 +2377,8 @@ static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, 
	ret = 0;

	if (iowq->timeout == KTIME_MAX)

		schedule();

	else if (!schedule_hrtimeout(&iowq->timeout, HRTIMER_MODE_ABS))

	else if (!schedule_hrtimeout_range_clock(&iowq->timeout, 0,

						 HRTIMER_MODE_ABS, ctx->clockid))

		ret = -ETIME;

	current->in_iowait = 0;

	return ret;
@@ -2422,7 +2423,7 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, u32 flags, 


		iowq.timeout = timespec64_to_ktime(ts);

		if (!(flags & IORING_ENTER_ABS_TIMER))

			iowq.timeout = ktime_add(iowq.timeout, ktime_get());

			iowq.timeout = ktime_add(iowq.timeout, io_get_time(ctx));

	}



	if (sig) {
@@ -3424,6 +3425,9 @@ static __cold int io_uring_create(unsigned entries, struct io_uring_params *p, 
	if (!ctx)

		return -ENOMEM;



	ctx->clockid = CLOCK_MONOTONIC;

	ctx->clock_offset = 0;



	if ((ctx->flags & IORING_SETUP_DEFER_TASKRUN) &&

	    !(ctx->flags & IORING_SETUP_IOPOLL) &&

	    !(ctx->flags & IORING_SETUP_SQPOLL))

io_uring/io_uring.h

+8 −0
Original line number Diff line number Diff line
@@ -437,6 +437,14 @@ static inline bool io_file_can_poll(struct io_kiocb *req) 
	return false;

}



static inline ktime_t io_get_time(struct io_ring_ctx *ctx)

{

	if (ctx->clockid == CLOCK_MONOTONIC)

		return ktime_get();



	return ktime_get_with_offset(ctx->clock_offset);

}



enum {

	IO_CHECK_CQ_OVERFLOW_BIT,

	IO_CHECK_CQ_DROPPED_BIT,

io_uring/napi.c

+1 −1
Original line number Diff line number Diff line
@@ -283,7 +283,7 @@ void __io_napi_busy_loop(struct io_ring_ctx *ctx, struct io_wait_queue *iowq) 


	iowq->napi_busy_poll_dt = READ_ONCE(ctx->napi_busy_poll_dt);

	if (iowq->timeout != KTIME_MAX) {

		ktime_t dt = ktime_sub(iowq->timeout, ktime_get());

		ktime_t dt = ktime_sub(iowq->timeout, io_get_time(ctx));



		iowq->napi_busy_poll_dt = min_t(u64, iowq->napi_busy_poll_dt, dt);

	}