[LTP] [PATCH] io_uring: enable I/O Uring before testing

[Jeff Moyer]

Li Wang <liwang@redhat.com> writes:

> Hi Jeff,
>
> Thanks for comments.
>
> On Tue, Aug 8, 2023 at 9:17 PM Jeff Moyer <jmoyer@redhat.com> wrote:
>
>> Li Wang <liwang@redhat.com> writes:
>>
>> > Given that the upstream kernel is going to introduce io_uring_disabled
>> > knob which disables the creation of new io_uring instances system-wide.
>> >
>> > The new sysctl is designed to let a user with root on the machine
>> > enable and disable io_uring system-wide at runtime without requiring
>> > a kernel recompilation or a reboot.
>> >
>> > See:
>> https://patchwork.kernel.org/project/io-uring/patch/20230630151003.3622786-2-matteorizzo@google.com/
>> >
>> > Without this patch, LTP/io_uring test complains:
>> >
>> >   io_uring01.c:82: TFAIL: io_uring_setup() failed: EPERM (1)
>> >   io_uring02.c:213: TBROK: io_uring_setup() failed: EPERM (1)
>>
>> Just to be clear, with the above kernel patch applied io_uring is
>> enabled by default.  You shouldn't need to set the sysctl parameter
>> unless io_uring is explicitly disabled by the administrator (that can be
>> accomplished via the kernel command line, sysfs, or via sysctl.conf).
>>
>
> Yes, but it won't be harmful to set the parameter even if it's enabled by
> default,
> LTP uses save_restore field to manage sysfs knob unified, it guarantees the
> tests can really get performed whatever io_uring is enabled or disabled.
>
> I would keep the patch as it is unless you insist or others have an
> objection.

I agree with the patch.  I just think the description should be updated,
as it implies that, without the patch, the test will fail.  This is not
the case for an upstream kernel.

Thanks!
Jeff

>
>
>>
>> Cheers,
>> Jeff
>>
>> >
>> > Reproted-by: Jeff Moyer <jmoyer@redhat.com>
>> > Signed-off-by: Li Wang <liwang@redhat.com>
>> > ---
>> >  testcases/kernel/syscalls/io_uring/io_uring01.c | 5 +++++
>> >  testcases/kernel/syscalls/io_uring/io_uring02.c | 5 +++++
>> >  2 files changed, 10 insertions(+)
>> >
>> > diff --git a/testcases/kernel/syscalls/io_uring/io_uring01.c
>> b/testcases/kernel/syscalls/io_uring/io_uring01.c
>> > index 70151bb85..ab1ec00d6 100644
>> > --- a/testcases/kernel/syscalls/io_uring/io_uring01.c
>> > +++ b/testcases/kernel/syscalls/io_uring/io_uring01.c
>> > @@ -264,5 +264,10 @@ static struct tst_test test = {
>> >       .bufs = (struct tst_buffers []) {
>> >               {&iov, .iov_sizes = (int[]){BLOCK_SZ, -1}},
>> >               {}
>> > +     },
>> > +     .save_restore = (const struct tst_path_val[]) {
>> > +             {"/proc/sys/kernel/io_uring_disabled", "0",
>> > +                     TST_SR_SKIP_MISSING | TST_SR_TCONF_RO},
>> > +             {}
>> >       }
>> >  };
>> > diff --git a/testcases/kernel/syscalls/io_uring/io_uring02.c
>> b/testcases/kernel/syscalls/io_uring/io_uring02.c
>> > index c5c770074..c9d4bbcb1 100644
>> > --- a/testcases/kernel/syscalls/io_uring/io_uring02.c
>> > +++ b/testcases/kernel/syscalls/io_uring/io_uring02.c
>> > @@ -255,6 +255,11 @@ static struct tst_test test = {
>> >               TST_CAP(TST_CAP_REQ, CAP_SYS_CHROOT),
>> >               {}
>> >       },
>> > +     .save_restore = (const struct tst_path_val[]) {
>> > +             {"/proc/sys/kernel/io_uring_disabled", "0",
>> > +                     TST_SR_SKIP_MISSING | TST_SR_TCONF_RO},
>> > +             {}
>> > +     },
>> >       .tags = (const struct tst_tag[]) {
>> >               {"linux-git", "9392a27d88b9"},
>> >               {"linux-git", "ff002b30181d"},
>>
>>