Re: [PATCH v5 6/7] selftests: prctl: introduce tests for disabling THPs completely

From: Usama Arif
Date: Mon Aug 18 2025 - 06:43:53 EST




On 18/08/2025 10:36, David Hildenbrand wrote:
>> +
>> +TEST_F(prctl_thp_disable_completely, fork)
>> +{
>> +    int ret = 0;
>> +    pid_t pid;
>> +
>> +    /* Make sure prctl changes are carried across fork */
>> +    pid = fork();
>> +    ASSERT_GE(pid, 0);
>> +
>> +    if (!pid)
>> +        prctl_thp_disable_completely_test(_metadata, self->pmdsize, variant->thp_policy);
>> +
>
> Skimming over this once more ... this raises two questions
>
> (a) There is nothing to wait for in the child
> (b) Does it work when we return in the child from this function?
>
> I think (b) works by design of the kselftest_harness, as this function is
> itself executed from a child process.
>
> Regarding (a), it might be cleaner to just
>

Makes sense, thanks for pointing this out! Have sent the fixlets.