Commit 15641e42 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: don't cache number of dropped SQEs 



Kill ->cached_sq_dropped and wire DRAIN sequence number correction via
->cq_extra, which is there exactly for that purpose. User visible
dropped counter will be populated by incrementing it instead of keeping
a copy, similarly as it was done not so long ago with cq_overflow.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/088aceb2707a534d531e2770267c4498e0507cc1.1623709150.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 17d3aeb3

fs/io_uring.c

+5 −7
Original line number Diff line number Diff line
@@ -370,7 +370,6 @@ struct io_ring_ctx { 
		struct io_uring_sqe	*sq_sqes;

		unsigned		cached_sq_head;

		unsigned		sq_entries;

		unsigned		cached_sq_dropped;

		unsigned long		sq_check_overflow;

		struct list_head	defer_list;
@@ -5994,13 +5993,11 @@ static u32 io_get_sequence(struct io_kiocb *req) 
{

	struct io_kiocb *pos;

	struct io_ring_ctx *ctx = req->ctx;

	u32 total_submitted, nr_reqs = 0;

	u32 nr_reqs = 0;



	io_for_each_link(pos, req)

		nr_reqs++;



	total_submitted = ctx->cached_sq_head - ctx->cached_sq_dropped;

	return total_submitted - nr_reqs;

	return ctx->cached_sq_head - nr_reqs;

}



static int io_req_defer(struct io_kiocb *req)
@@ -6701,8 +6698,9 @@ static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx) 
		return &ctx->sq_sqes[head];



	/* drop invalid entries */

	ctx->cached_sq_dropped++;

	WRITE_ONCE(ctx->rings->sq_dropped, ctx->cached_sq_dropped);

	ctx->cq_extra--;

	WRITE_ONCE(ctx->rings->sq_dropped,

		   READ_ONCE(ctx->rings->sq_dropped) + 1);

	return NULL;

}