Commit 4ce8ad95 authored by Olivier Langlois's avatar Olivier Langlois Committed by Jens Axboe
Browse files

io_uring: Create define to modify a SQPOLL parameter 



The magic number used to cap the number of entries extracted from an
io_uring instance SQ before moving to the other instances is an
interesting parameter to experiment with.

A define has been created to make it easy to change its value from a
single location.

Signed-off-by: default avatarOlivier Langlois <olivier@trillion01.com>
Reviewed-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b401640063e77ad3e9f921e09c9b3ac10a8bb923.1624473200.git.olivier@trillion01.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 99713501

fs/io_uring.c

+3 −2
Original line number Diff line number Diff line
@@ -89,6 +89,7 @@ 


#define IORING_MAX_ENTRIES	32768

#define IORING_MAX_CQ_ENTRIES	(2 * IORING_MAX_ENTRIES)

#define IORING_SQPOLL_CAP_ENTRIES_VALUE 8



/*

 * Shift of 9 is 512 entries, or exactly one page on 64-bit archs
@@ -6797,8 +6798,8 @@ static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries) 


	to_submit = io_sqring_entries(ctx);

	/* if we're handling multiple rings, cap submit size for fairness */

	if (cap_entries && to_submit > 8)

		to_submit = 8;

	if (cap_entries && to_submit > IORING_SQPOLL_CAP_ENTRIES_VALUE)

		to_submit = IORING_SQPOLL_CAP_ENTRIES_VALUE;



	if (!list_empty(&ctx->iopoll_list) || to_submit) {

		unsigned nr_events = 0;