On Tue, 9 Apr 2024 at 13:12, Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
>
> On 04/09, Thomas Gleixner wrote:
> >
> > The discussion started about running new tests on older kernels. As this
> > is a feature and not a bug fix that obviously fails on older kernels.
>
> OK, I see... please see below.
>
> > So something like the uncompiled below should work.
>
> Hmm... this patch doesn't apply to Linus's tree...
>
> It seems that this is because in your tree check_timer_distribution() does
>
> if (timer_delete(id)) {
> ksft_perror("Can't delete timer");
> return 0;
> }
>
> while in Linus's tree it returns -1 if timer_delete() fails. Nevermind.
>
> Thomas, I am almost shy to continue this discussion and waste your time ;)
> But ...
>
> > +static bool check_kernel_version(unsigned int min_major, unsigned int min_minor)
> > +{
> > + unsigned int major, minor;
> > + struct utsname info;
> > +
> > + uname(&info);
> > + if (sscanf(info.release, "%u.%u.", &major, &minor) != 2)
> > + ksft_exit_fail();
> > + return major > min_major || (major == min_major && minor >= min_minor);
> > +}
>
> this looks useful regardless. Perhaps it should be moved into
> tools/testing/selftests/kselftest.h as ksft_ck_kernel_version() ?
>
> > +static int check_timer_distribution(void)
> > +{
> > + const char *errmsg;
> > +
> > + if (!check_kernel_version(6, 3)) {
> > + ksft_test_result_skip("check signal distribution (old kernel)\n");
> > return 0;
>
> ...
>
> > + ksft_test_result(!ctd_failed, "check signal distribution\n");
>
> Perhaps
>
> if (!ctd_failed)
> ksft_test_result_pass("check signal distribution\n");
> else if (check_kernel_version(6, 3))
> ksft_test_result_fail("check signal distribution\n");
> else
> ksft_test_result_skip("check signal distribution (old kernel)\n");
>
> makes more sense?
This looks even better!
> This way it can be used on the older kernels with bcb7ee79029d backported.
>
> Oleg.
>
