Re: [PATCH RFC 1/1] block/export: FUSE-over-io_uring Support for QEMU FUSE Exports

[Stefan Hajnoczi <stefanha@redhat.com>]

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On Mon, Jul 21, 2025 at 01:51:44PM +0000, Bernd Schubert wrote:
> I need test these flags again, might be worthful for qemu as well
> 
> 	/* These flags should help to increase performance, but actually
> 	 * make it a bit slower - reason should get investigated.
> 	 */
> 	if (0) {
> 		/* Has the main slow down effect */
> 		params.flags |= IORING_SETUP_SINGLE_ISSUER;
> 
> 		// params.flags |= IORING_SETUP_DEFER_TASKRUN;
> 		params.flags |= IORING_SETUP_TASKRUN_FLAG;
> 
> 		/* Second main effect to make it slower */
> 		params.flags |= IORING_SETUP_COOP_TASKRUN;
> 	}

Yes, they are interesting. Thanks for mentioning them!

An earlier attempt at enabling IORING_SETUP_SINGLE_ISSUER in QEMU (still
needs benchmarking):
https://lore.kernel.org/qemu-devel/174293621917.22751.11381319865102029969-0%40git.sr.ht/T/#t

Let's consider these flags as a separate patch series. I have a
benchmarking setup that can be used for measurement, so I'll take this
as a TODO item for myself to work on over the coming days.

Thanks,
Stefan

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