On Tue, Mar 31, 2026 at 10:19:44PM -0700, Matthew Brost wrote: > On Tue, Mar 31, 2026 at 05:34:44PM +1100, Alistair Popple wrote: > > Several HMM tests hardcode TWOMEG as the THP size. This is wrong on > > architectures where the PMD size is not 2MB such as arm64 with 64K base > > +1 > > But one question… > > Can’t the THP size be derived via HPAGE_PMD_ORDER? > > If not, then some DRM common code I’ve written will break on arm64. >
Ignore this I seemly forgot we are in userspace here. Matt > Matt > > > pages where THP is 512MB. Fix this by using read_pmd_pagesize() from > > vm_util instead. > > > > While here also replace the custom file_read_ulong() helper used to > > parse the default hugetlbfs page size from /proc/meminfo with the > > existing default_huge_page_size() from vm_util. > > > > [1] > > https://lore.kernel.org/linux-mm/[email protected]/ > > > > Fixes: fee9f6d1b8df ("mm/hmm/test: add selftests for HMM") > > Fixes: 519071529d2a ("selftests/mm/hmm-tests: new tests for zone device THP > > migration") > > Reported-by: Zenghui Yu <[email protected]> > > Closes: > > https://lore.kernel.org/linux-mm/[email protected]/ > > Signed-off-by: Alistair Popple <[email protected]> > > --- > > tools/testing/selftests/mm/hmm-tests.c | 83 +++++--------------------- > > 1 file changed, 16 insertions(+), 67 deletions(-) > > > > diff --git a/tools/testing/selftests/mm/hmm-tests.c > > b/tools/testing/selftests/mm/hmm-tests.c > > index e8328c89d855..788689497e92 100644 > > --- a/tools/testing/selftests/mm/hmm-tests.c > > +++ b/tools/testing/selftests/mm/hmm-tests.c > > @@ -34,6 +34,7 @@ > > */ > > #include <lib/test_hmm_uapi.h> > > #include <mm/gup_test.h> > > +#include <mm/vm_util.h> > > > > struct hmm_buffer { > > void *ptr; > > @@ -548,7 +549,7 @@ TEST_F(hmm, anon_write_child) > > > > for (migrate = 0; migrate < 2; ++migrate) { > > for (use_thp = 0; use_thp < 2; ++use_thp) { > > - npages = ALIGN(use_thp ? TWOMEG : HMM_BUFFER_SIZE, > > + npages = ALIGN(use_thp ? read_pmd_pagesize() : > > HMM_BUFFER_SIZE, > > self->page_size) >> self->page_shift; > > ASSERT_NE(npages, 0); > > size = npages << self->page_shift; > > @@ -728,7 +729,7 @@ TEST_F(hmm, anon_write_huge) > > int *ptr; > > int ret; > > > > - size = 2 * TWOMEG; > > + size = 2 * read_pmd_pagesize(); > > > > buffer = malloc(sizeof(*buffer)); > > ASSERT_NE(buffer, NULL); > > @@ -744,7 +745,7 @@ TEST_F(hmm, anon_write_huge) > > buffer->fd, 0); > > ASSERT_NE(buffer->ptr, MAP_FAILED); > > > > - size = TWOMEG; > > + size /= 2; > > npages = size >> self->page_shift; > > map = (void *)ALIGN((uintptr_t)buffer->ptr, size); > > ret = madvise(map, size, MADV_HUGEPAGE); > > @@ -770,54 +771,6 @@ TEST_F(hmm, anon_write_huge) > > hmm_buffer_free(buffer); > > } > > > > -/* > > - * Read numeric data from raw and tagged kernel status files. Used to read > > - * /proc and /sys data (without a tag) and from /proc/meminfo (with a tag). > > - */ > > -static long file_read_ulong(char *file, const char *tag) > > -{ > > - int fd; > > - char buf[2048]; > > - int len; > > - char *p, *q; > > - long val; > > - > > - fd = open(file, O_RDONLY); > > - if (fd < 0) { > > - /* Error opening the file */ > > - return -1; > > - } > > - > > - len = read(fd, buf, sizeof(buf)); > > - close(fd); > > - if (len < 0) { > > - /* Error in reading the file */ > > - return -1; > > - } > > - if (len == sizeof(buf)) { > > - /* Error file is too large */ > > - return -1; > > - } > > - buf[len] = '\0'; > > - > > - /* Search for a tag if provided */ > > - if (tag) { > > - p = strstr(buf, tag); > > - if (!p) > > - return -1; /* looks like the line we want isn't there */ > > - p += strlen(tag); > > - } else > > - p = buf; > > - > > - val = strtol(p, &q, 0); > > - if (*q != ' ') { > > - /* Error parsing the file */ > > - return -1; > > - } > > - > > - return val; > > -} > > - > > /* > > * Write huge TLBFS page. > > */ > > @@ -826,15 +779,13 @@ TEST_F(hmm, anon_write_hugetlbfs) > > struct hmm_buffer *buffer; > > unsigned long npages; > > unsigned long size; > > - unsigned long default_hsize; > > + unsigned long default_hsize = default_huge_page_size(); > > unsigned long i; > > int *ptr; > > int ret; > > > > - default_hsize = file_read_ulong("/proc/meminfo", "Hugepagesize:"); > > - if (default_hsize < 0 || default_hsize*1024 < default_hsize) > > + if (!default_hsize) > > SKIP(return, "Huge page size could not be determined"); > > - default_hsize = default_hsize*1024; /* KB to B */ > > > > size = ALIGN(TWOMEG, default_hsize); > > npages = size >> self->page_shift; > > @@ -1606,7 +1557,7 @@ TEST_F(hmm, compound) > > struct hmm_buffer *buffer; > > unsigned long npages; > > unsigned long size; > > - unsigned long default_hsize; > > + unsigned long default_hsize = default_huge_page_size(); > > int *ptr; > > unsigned char *m; > > int ret; > > @@ -1614,10 +1565,8 @@ TEST_F(hmm, compound) > > > > /* Skip test if we can't allocate a hugetlbfs page. */ > > > > - default_hsize = file_read_ulong("/proc/meminfo", "Hugepagesize:"); > > - if (default_hsize < 0 || default_hsize*1024 < default_hsize) > > + if (!default_hsize) > > SKIP(return, "Huge page size could not be determined"); > > - default_hsize = default_hsize*1024; /* KB to B */ > > > > size = ALIGN(TWOMEG, default_hsize); > > npages = size >> self->page_shift; > > @@ -2106,7 +2055,7 @@ TEST_F(hmm, migrate_anon_huge_empty) > > int *ptr; > > int ret; > > > > - size = TWOMEG; > > + size = read_pmd_pagesize(); > > > > buffer = malloc(sizeof(*buffer)); > > ASSERT_NE(buffer, NULL); > > @@ -2158,7 +2107,7 @@ TEST_F(hmm, migrate_anon_huge_zero) > > int ret; > > int val; > > > > - size = TWOMEG; > > + size = read_pmd_pagesize(); > > > > buffer = malloc(sizeof(*buffer)); > > ASSERT_NE(buffer, NULL); > > @@ -2221,7 +2170,7 @@ TEST_F(hmm, migrate_anon_huge_free) > > int *ptr; > > int ret; > > > > - size = TWOMEG; > > + size = read_pmd_pagesize(); > > > > buffer = malloc(sizeof(*buffer)); > > ASSERT_NE(buffer, NULL); > > @@ -2280,7 +2229,7 @@ TEST_F(hmm, migrate_anon_huge_fault) > > int *ptr; > > int ret; > > > > - size = TWOMEG; > > + size = read_pmd_pagesize(); > > > > buffer = malloc(sizeof(*buffer)); > > ASSERT_NE(buffer, NULL); > > @@ -2332,7 +2281,7 @@ TEST_F(hmm, migrate_partial_unmap_fault) > > { > > struct hmm_buffer *buffer; > > unsigned long npages; > > - unsigned long size = TWOMEG; > > + unsigned long size = read_pmd_pagesize(); > > unsigned long i; > > void *old_ptr; > > void *map; > > @@ -2398,7 +2347,7 @@ TEST_F(hmm, migrate_remap_fault) > > { > > struct hmm_buffer *buffer; > > unsigned long npages; > > - unsigned long size = TWOMEG; > > + unsigned long size = read_pmd_pagesize(); > > unsigned long i; > > void *old_ptr, *new_ptr = NULL; > > void *map; > > @@ -2498,7 +2447,7 @@ TEST_F(hmm, migrate_anon_huge_err) > > int *ptr; > > int ret; > > > > - size = TWOMEG; > > + size = read_pmd_pagesize(); > > > > buffer = malloc(sizeof(*buffer)); > > ASSERT_NE(buffer, NULL); > > @@ -2593,7 +2542,7 @@ TEST_F(hmm, migrate_anon_huge_zero_err) > > int *ptr; > > int ret; > > > > - size = TWOMEG; > > + size = read_pmd_pagesize(); > > > > buffer = malloc(sizeof(*buffer)); > > ASSERT_NE(buffer, NULL); > > -- > > 2.53.0 > >
