> On 10/1/26 15:52, Yeoreum Yun wrote:
> >> On 9/29/26 12:01, Yeoreum Yun wrote:
> >>>
> >>> Okay. I'll change like below in next-spin:
> >>>
> >>> -------&<-------
> >>>
> >>> @@ -411,57 +400,78 @@ static bool check_huge_type(uint64_t categories,
> >>> enum check_huge_type type)
> >>> return false;
> >>> }
> >>>
> >>> -static bool __check_pmd_huge(void *addr, size_t len, int nr_hpages,
> >>> - uint64_t hpage_size, enum check_huge_type type)
> >>> +static bool __check_huge(void *addr, size_t len, int nr_hpages,
> >>> + uint64_t hpage_size, enum check_huge_type type)
> >>> {
> >>> {
> >>> - int pagemap_fd;
> >>> + bool ret = false;
> >>> + int pagemap_fd, kpageflags_fd;
> >>> int nr_pmd_mappings = 0;
> >>> + uint64_t pmd_pagesize, scan_mapping_size;
> >>> uint64_t categories;
> >>> + unsigned long pfn;
> >>> + bool check_pmd_mapping, allow_nonpresent;
> >>> char *start = addr;
> >>> char *end = start + len;
> >>>
> >>> + pmd_pagesize = read_pmd_pagesize();
> >>> + if (!pmd_pagesize)
> >>> + ksft_exit_fail_msg("reading PMD pagesize failed\n");
> >>> +
> >>> + check_pmd_mapping = hpage_size == pmd_pagesize;
> >>> + scan_mapping_size = (nr_hpages > 0) ? hpage_size : psize();
> >>> + /* Some mTHP tests check a partially populated PMD-sized range. */
> >>> + allow_nonpresent = (uint64_t)nr_hpages * hpage_size < len;
> >>> +
> >>> pagemap_fd = open(PAGEMAP_PATH, O_RDONLY);
> >>> if (pagemap_fd < 0)
> >>> ksft_exit_fail_perror("open pagemap");
> >>>
> >>> - for (; start < end; start += hpage_size) {
> >>> + kpageflags_fd = open(KPAGEFLAGS_PATH, O_RDONLY);
> >>> + if (kpageflags_fd < 0)
> >>> + ksft_exit_fail_perror("open kpageflags");
> >>> +
> >>> + for (; start < end; start += scan_mapping_size) {
> >>> categories = pagemap_scan_get_categories(pagemap_fd,
> >>> start);
> >>> - if (!(categories & PAGE_IS_HUGE))
> >>> + pfn = pagemap_get_pfn(pagemap_fd, start);
> >>> + if (pfn == -1UL) {
> >>> + if (!allow_nonpresent)
> >>> + goto out;
> >>> continue;
> >>> - if (check_huge_type(categories, type))
> >>> + }
> >>> + if (!check_huge_type(categories, type))
> >>> + goto out;
> >>> + }
> >>> +
> >>> + if (!check_pmd_mapping) {
> >>> + ret = check_large_folios(pagemap_fd, kpageflags_fd,
> >>> + addr, len, nr_hpages, hpage_size);
> >>> + goto out;
> >>> + }
> >>> +
> >>> + for (start = addr; start < end; start += scan_mapping_size) {
> >>> + categories = pagemap_scan_get_categories(pagemap_fd,
> >>> start);
> >>> + if (categories & PAGE_IS_HUGE)
> >>> nr_pmd_mappings++;
> >>> }
> >>> - close(pagemap_fd);
> >>>
> >>> - return nr_hpages == nr_pmd_mappings;
> >>> + if (nr_pmd_mappings != nr_hpages)
> >>> + goto out;
> >>> + ret = true;
> >>> +
> >>> +out:
> >>> + close(pagemap_fd);
> >>> + close(kpageflags_fd);
> >>> + return ret;
> >>> }
> >>>
> >>
> >> I'd leave existing __check_huge() mostly alone, and instead have an
> >> additional
> >> function that checks the type.
> >>
> >> Essentially a __check_type() or sth that we run after the large folio /
> >> pmd check.
> >
> > So, You mean like this?
> >
> > -------&<-------
> >
> > -enum check_huge_type {
> > - CHECK_HUGE_ANON,
> > - CHECK_HUGE_FILE,
> > +enum check_type {
> > + CHECK_TYPE_ANON,
> > + CHECK_TYPE_FILE,
> > };
> >
> > -static bool check_huge_type(uint64_t categories, enum check_huge_type type)
> > +static bool __check_type(void *addr, size_t len, uint64_t page_size,
> > + bool allow_nonpresent, enum check_type type)
>
>
> As discussed off-list, maybe we can avoid the allow_nonpresent handling!
Okay. I'll change. Thanks!
--
Sincerely,
Yeoreum Yun
