which liburing library version should I use for kernel 5.10?

[osevan]

Which version is latest stable one for kernel 5.10?

Thanks and

Best regards

[axboe]

Just use the latest one, liburing and the kernel aren't tied to each other, it's just that some features are only available on newer kernels. But you can use the 2.1 release with 5.10 just fine, as well as the upcoming 2.2.

[victorstewart]

but it'll fail to build if new opcodes were added to liburing to support newer kernel operations, because the enum values aren't in the older kernel's header file. i've encountered that a few times.

[osevan]

Just use the latest one, liburing and the kernel aren't tied to each other, it's just that some features are only available on newer kernels. But you can use the 2.1 release with 5.10 just fine, as well as the upcoming 2.2.

New version are more performing better than normal versions?

This is important too for me.

Thanks and

Best regards

[axboe]

The current master branch, which will become 2.2, does have a few optimizations over the 2.1 release. So yes, it should be better. As usual, also fixes bugs found in 2.1.

[axboe]

but it'll fail to build if new opcodes were added to liburing to support newer kernel operations, because the enum values aren't in the older kernel's header file. i've encountered that a few times.

How so? liburing doesn't depend on any kernel io_uring headers, it carries its own for that very reason.

[axboe]

This is not making sense to me. This is clearly at compile time, not runtime. Are you using a liburing.h with an io_uring.h from an older kernel somehow? This sounds like a build issue, something specific on your end? You have a non-coherent set of headers, are you including io_uring.h from your app somehow before liburing.h? Just guessing here.

I had to look to see what system header I have it installed, it's a lot older than the liburing once I'm building. I built all versions since 0.7 and up and I don't see anything like this.

[axboe]

haha given the self contained point you made, now i'm guessing there's a header with all these definitions that i haven't been including?

You don't need to include anything outside of liburing.h, in fact my strong suspicion above is that you are including some unrelated io_uring.h that came from another package?

[axboe]

How did you install liburing? Package or self-installed? liburing puts the header in install-path/include/liburing.h and the other headers from liburing end up in liburing/.

[victorstewart]

right i meant when you compile the application. ahh you solved it! from way back when i had this line #include <linux/io_uring.h> included 🙄

[axboe]

Mystery solved! Back to the original question, my original comment still stands. Use the latest version, there are no kernel dependencies. EOD ;-)