Re: [PATCH] kunit: time: Add faster unit test with shorter time range

[Guenter Roeck <linux@roeck-us.net>]

On 3/14/24 12:05, Rae Moar wrote:
> On Wed, Mar 13, 2024 at 5:01 PM Guenter Roeck <linux@roeck-us.net> wrote:
>>
>> Commit a547c4ce10bd ("kunit: time: Mark test as slow using test
>> attributes") marked the time unit test as slow. This means it does not
>> run anymore if slow tests are disabled. This reduces test coverage and
>> is thus undesirable. At the same time, the test currently covers a range
>> of 160,000 years, which has limited value.
>>
>> Add additional test case covering a total range of 1,600 years. This test
>> takes less than a second to run even on slow systems while still covering
>> twice the leap year calculation range of 400 years around the center date.
>> This test can run even with slow tests disabled.
> 
> Hello!
> 
> I really like this addition of another time range test. This looks good to me.
> 
> Thanks!
> -Rae
> 
> Reviewed-by: Rae Moar <rmoar@google.com>
> 
>>
>> Cc: Rae Moar <rmoar@google.com>
>> Cc: Shuah Khan <skhan@linuxfoundation.org>
>> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
>> ---
>>   kernel/time/time_test.c | 35 +++++++++++++++++++++++++++--------
>>   1 file changed, 27 insertions(+), 8 deletions(-)
>>
>> diff --git a/kernel/time/time_test.c b/kernel/time/time_test.c
>> index 3e5d422dd15c..15c6f3a5e73c 100644
>> --- a/kernel/time/time_test.c
>> +++ b/kernel/time/time_test.c
>> @@ -47,18 +47,18 @@ static void advance_date(long *year, int *month, int *mday, int *yday)
>>   }
>>
>>   /*
>> - * Checks every day in a 160000 years interval centered at 1970-01-01
>> + * Checks every day in a specified interval centered at 1970-01-01
>>    * against the expected result.
>>    */
>> -static void time64_to_tm_test_date_range(struct kunit *test)
>> +static void time64_to_tm_test_date_range(struct kunit *test, int years)
>>   {
>>          /*
>> -        * 80000 years  = (80000 / 400) * 400 years
>> -        *              = (80000 / 400) * 146097 days
>> -        *              = (80000 / 400) * 146097 * 86400 seconds
>> +        * years        = (years / 400) * 400 years
> 
> This is tiny but if there is another version, I find this comment a
> bit confusing. Could you change this to maybe be "total seconds ="
> instead of "years =" because years is used as a unit on the right side
> of the equation?
> 

Good point. "total seconds" might be just as confusing, though.
How about "total range", "time range", or just "range" ?

Thanks,
Guenter