On 3/19/22 12:23 AM, Gabriel Krisman Bertazi wrote:
>> +static void test_vma_reuse(int pagemap_fd, int pagesize)
>> +{
>> + char *map, *map2;
>> +
>> + map = mmap(NULL, pagesize, (PROT_READ | PROT_WRITE), (MAP_PRIVATE | MAP_ANON), -1, 0);
>> + if (map == MAP_FAILED)
>> + ksft_exit_fail_msg("mmap failed");
>> +
>> + clear_softdirty();
>> +
>> + /* Write to the page before unmapping and map the same size region again to check
>> + * if same memory region is gotten next time and if dirty bit is preserved across
>> + * this type of allocations.
>> + */
> This reads weird. It should *not* be preserved across different
> mappings. Also, we are not testing if the same region is reused, we are
> depending on it to test the sd bit.
>
> /* Ensures the soft-dirty bit is reset accross different mappings on the
> same address. */
Soft dirty bit is always set for new regions (reused or not). I'll
correct the comment and improve this sub test.
--
Muhammad Usama Anjum
