(cc Muchun) On Wed, 10 Jan 2024 14:03:35 +0530 Donet Tom <donet...@linux.vnet.ibm.com> wrote:
> The kernel sefltest mm/hugepage-vmemmap fails on architectures > which has different page size other than 4K. In hugepage-vmemmap > page size used is 4k so the pfn calculation will go wrong on systems > which has different page size .The length of MAP_HUGETLB memory must > be hugepage aligned but in hugepage-vmemmap map length is 2M so this > will not get aligned if the system has differnet hugepage size. > > Added psize() to get the page size and default_huge_page_size() to > get the default hugepage size at run time, hugepage-vmemmap test pass > on powerpc with 64K page size and x86 with 4K page size. > > Result on powerpc without patch (page size 64K) > *# ./hugepage-vmemmap > Returned address is 0x7effff000000 whose pfn is 0 > Head page flags (100000000) is invalid > check_page_flags: Invalid argument > *# > > Result on powerpc with patch (page size 64K) > *# ./hugepage-vmemmap > Returned address is 0x7effff000000 whose pfn is 600 > *# > > Result on x86 with patch (page size 4K) > *# ./hugepage-vmemmap > Returned address is 0x7fc7c2c00000 whose pfn is 1dac00 > *# > > Signed-off-by: Donet Tom <donet...@linux.vnet.ibm.com> > Reported-by : Geetika Moolchandani (geet...@linux.ibm.com) > Tested-by : Geetika Moolchandani (geet...@linux.ibm.com) I'll add Fixes: b147c89cd429 ("selftests: vm: add a hugetlb test case") Cc: <sta...@vger.kernel.org> > > diff --git a/tools/testing/selftests/mm/hugepage-vmemmap.c > b/tools/testing/selftests/mm/hugepage-vmemmap.c > index 5b354c209e93..894d28c3dd47 100644 > --- a/tools/testing/selftests/mm/hugepage-vmemmap.c > +++ b/tools/testing/selftests/mm/hugepage-vmemmap.c > @@ -10,10 +10,7 @@ > #include <unistd.h> > #include <sys/mman.h> > #include <fcntl.h> > - > -#define MAP_LENGTH (2UL * 1024 * 1024) > - > -#define PAGE_SIZE 4096 > +#include "vm_util.h" > > #define PAGE_COMPOUND_HEAD (1UL << 15) > #define PAGE_COMPOUND_TAIL (1UL << 16) > @@ -39,6 +36,9 @@ > #define MAP_FLAGS (MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB) > #endif > > +static size_t pagesize; > +static size_t maplength; > + > static void write_bytes(char *addr, size_t length) > { > unsigned long i; > @@ -56,7 +56,7 @@ static unsigned long virt_to_pfn(void *addr) > if (fd < 0) > return -1UL; > > - lseek(fd, (unsigned long)addr / PAGE_SIZE * sizeof(pagemap), SEEK_SET); > + lseek(fd, (unsigned long)addr / pagesize * sizeof(pagemap), SEEK_SET); > read(fd, &pagemap, sizeof(pagemap)); > close(fd); > > @@ -86,7 +86,7 @@ static int check_page_flags(unsigned long pfn) > * this also verifies kernel has correctly set the fake page_head to > tail > * while hugetlb_free_vmemmap is enabled. > */ > - for (i = 1; i < MAP_LENGTH / PAGE_SIZE; i++) { > + for (i = 1; i < maplength / pagesize; i++) { > read(fd, &pageflags, sizeof(pageflags)); > if ((pageflags & TAIL_PAGE_FLAGS) != TAIL_PAGE_FLAGS || > (pageflags & HEAD_PAGE_FLAGS) == HEAD_PAGE_FLAGS) { > @@ -106,18 +106,25 @@ int main(int argc, char **argv) > void *addr; > unsigned long pfn; > > - addr = mmap(MAP_ADDR, MAP_LENGTH, PROT_READ | PROT_WRITE, MAP_FLAGS, > -1, 0); > + pagesize = psize(); > + maplength = default_huge_page_size(); > + if (!maplength) { > + printf("Unable to determine huge page size\n"); > + exit(1); > + } > + > + addr = mmap(MAP_ADDR, maplength, PROT_READ | PROT_WRITE, MAP_FLAGS, -1, > 0); > if (addr == MAP_FAILED) { > perror("mmap"); > exit(1); > } > > /* Trigger allocation of HugeTLB page. */ > - write_bytes(addr, MAP_LENGTH); > + write_bytes(addr, maplength); > > pfn = virt_to_pfn(addr); > if (pfn == -1UL) { > - munmap(addr, MAP_LENGTH); > + munmap(addr, maplength); > perror("virt_to_pfn"); > exit(1); > } > @@ -125,13 +132,13 @@ int main(int argc, char **argv) > printf("Returned address is %p whose pfn is %lx\n", addr, pfn); > > if (check_page_flags(pfn) < 0) { > - munmap(addr, MAP_LENGTH); > + munmap(addr, maplength); > perror("check_page_flags"); > exit(1); > } > > /* munmap() length of MAP_HUGETLB memory must be hugepage aligned */ > - if (munmap(addr, MAP_LENGTH)) { > + if (munmap(addr, maplength)) { > perror("munmap"); > exit(1); > } > -- > 2.43.0