What kernel version do you need for multishot timeouts?

[cmazakas]

I'm reading the man page for io_uring_prep_timeout.3 and I'm noticing that I keep getting -EINVAL when I setup the multishot timeout SQE.

I looked into liburing's test and it seems like it skips this if the platform doesn't support it. I went into test/timeout.c and updated the code to do:

ret = cqe->res;
if (ret == -EINVAL) {
  printf("noooooooo, say it ain't soooo!!!!!!\n");
	no_multishot = 1;
	return T_EXIT_SKIP;
}

and in my terminal, I see:

exbigboss@exbigboss-XPS-9315:~/cpp/liburing$ ./test/timeout.t 
noooooooo, say it ain't soooo!!!!!!

So it seems like this is expected on my platform. I'm using Ubuntu 23.04 w/ kernel 6.2 so I'm a little surprised this doesn't seem to work:

exbigboss@exbigboss-XPS-9315:~/cpp/liburing$ uname -a
Linux exbigboss-XPS-9315 6.2.0-33-generic #33-Ubuntu SMP PREEMPT_DYNAMIC Tue Sep  5 14:49:19 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

[cmazakas]

Alright, I upgraded to Ubuntu 23.10 from 23.04 (i.e. 6.2 -> 6.5) and now it seems to be working.

[axboe]

It was added with 6.4 - usually I add that to the man pages, but looks like this one was forgotten. Will do that now.