On 1/28/22 15:46, Shuah Khan wrote:
> On 1/28/22 3:26 PM, Mike Kravetz wrote:
>> Now that MADV_DONTNEED support for hugetlb is enabled, add corresponding
>> tests. MADV_REMOVE has been enabled for some time, but no tests exist
>> so add them as well.
>>
>> Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
>> ---
>> tools/testing/selftests/vm/Makefile | 1 +
>> tools/testing/selftests/vm/hugetlb-madvise.c | 401 +++++++++++++++++++
>> tools/testing/selftests/vm/run_vmtests.sh | 12 +
>> 3 files changed, 414 insertions(+)
>> create mode 100644 tools/testing/selftests/vm/hugetlb-madvise.c
>>
>> diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile
>> index 1607322a112c..f60cf43bbf61 100644
>> --- a/tools/testing/selftests/vm/Makefile
>> +++ b/tools/testing/selftests/vm/Makefile
>> @@ -28,6 +28,7 @@ LDLIBS = -lrt -lpthread
>> TEST_GEN_FILES = compaction_test
>> TEST_GEN_FILES += gup_test
>> TEST_GEN_FILES += hmm-tests
>> +TEST_GEN_FILES += hugetlb-madvise
>
> Please update .gitignore with the new binary.
>
Will do.
>> TEST_GEN_FILES += hugepage-mmap
>> TEST_GEN_FILES += hugepage-mremap
>> TEST_GEN_FILES += hugepage-shm
>> diff --git a/tools/testing/selftests/vm/hugetlb-madvise.c b/tools/testing/selftests/vm/hugetlb-madvise.c
>> new file mode 100644
>> index 000000000000..31c302528f2c
>> --- /dev/null
>> +++ b/tools/testing/selftests/vm/hugetlb-madvise.c
>> @@ -0,0 +1,401 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * hugepage-madvise:
>> + *
>> + * Basic functional testing of madvise MADV_DONTNEED and MADV_REMOVE
>> + * on hugetlb mappings.
>> + *
>> + * Before running this test, make sure the administrator has pre-allocated
>> + * at least MIN_FREE_PAGES hugetlb pages and they are free. In addition,
>> + * the test takes an argument that is the path to a file in a hugetlbfs
>> + * filesystem. Therefore, a hugetlbfs filesystem must be mounted on some
>> + * directory.
>> + */
>> +
>> +#include <stdlib.h>
>> +#include <stdio.h>
>> +#include <unistd.h>
>> +#include <sys/mman.h>
>> +#define __USE_GNU
>> +#include <fcntl.h>
>> +
>> +#define USAGE "USAGE: %s <hugepagefile_name>\n"
>> +#define MIN_FREE_PAGES 20
>> +
>> +#define validate_free_pages(exp_free) \
>> + do { \
>> + int fhp = get_free_hugepages(); \
>> + if (fhp != (exp_free)) { \
>> + printf("Unexpected number of free huge " \
>> + "pages line %d\n", __LINE__); \
>> + exit(1); \
>> + } \
>> + } while (0)
>> +
>> +unsigned long huge_page_size;
>> +unsigned long base_page_size;
>> +
>> +/*
>> + * default_huge_page_size copied from mlock2-tests.c
>> + */
>> +unsigned long default_huge_page_size(void)
>> +{
>> + unsigned long hps = 0;
>> + char *line = NULL;
>> + size_t linelen = 0;
>> + FILE *f = fopen("/proc/meminfo", "r");
>> +
>> + if (!f)
>> + return 0;
>> + while (getline(&line, &linelen, f) > 0) {
>> + if (sscanf(line, "Hugepagesize: %lu kB", &hps) == 1) {
>> + hps <<= 10;
>> + break;
>> + }
>> + }
>> +
>> + free(line);
>> + fclose(f);
>> + return hps;
>> +}
>> +
>> +unsigned long get_free_hugepages(void)
>> +{
>> + unsigned long fhp = 0;
>> + char *line = NULL;
>> + size_t linelen = 0;
>> + FILE *f = fopen("/proc/meminfo", "r");
>> +
>> + if (!f)
>> + return fhp;
>> + while (getline(&line, &linelen, f) > 0) {
>> + if (sscanf(line, "HugePages_Free: %lu", &fhp) == 1)
>> + break;
>> + }
>> +
>> + free(line);
>> + fclose(f);
>> + return fhp;
>> +}
>> +
>> +void write_fault_pages(void *addr, unsigned long nr_pages)
>> +{
>> + unsigned long i;
>> +
>> + for (i = 0; i < nr_pages; i++)
>> + *((unsigned long *)(addr + (i * huge_page_size))) = i;
>> +}
>> +
>> +void read_fault_pages(void *addr, unsigned long nr_pages)
>> +{
>> + unsigned long i, tmp;
>> +
>> + for (i = 0; i < nr_pages; i++)
>> + tmp += *((unsigned long *)(addr + (i * huge_page_size)));
>> +}
>> +
>> +int main(int argc, char **argv)
>> +{
>> + unsigned long free_hugepages;
>> + void *addr, *addr2;
>> + int fd;
>> + int ret;
>> +
>> + if (argc != 2) {
>> + printf(USAGE, argv[0]);
>> + exit(1);
>> + }
>> +
>> + huge_page_size = default_huge_page_size();
>> + if (!huge_page_size) {
>> + printf("Unable to determine huge page size, exiting!\n");
>> + exit(1);
>> + }
>> + base_page_size = sysconf(_SC_PAGE_SIZE);
>> + if (!huge_page_size) {
>> + printf("Unable to determine base page size, exiting!\n");
>> + exit(1);
>> + }
>> +
>> + free_hugepages = get_free_hugepages();
>> + if (free_hugepages < MIN_FREE_PAGES) {
>> + printf("Not enough free huge pages to test, exiting!\n");
>> + exit(1);
>> + }
>> +
>> + fd = open(argv[1], O_CREAT | O_RDWR, 0755);
>> + if (fd < 0) {
>> + perror("Open failed");
>> + exit(1);
>> + }
>> +
>> + /*
>> + * Test validity of MADV_DONTNEED addr and length arguments
>> + */
>> + addr = mmap(NULL, 12 * huge_page_size, PROT_READ | PROT_WRITE,
>> + MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
>> + -1, 0);
>
> What is 12 here? Any significance to this value? Add a define for it
> so it it clear why it is used.
I'll add a commented #define for the 10 as that is used throughout the
file. I'll add a comment here about mapping and then upmapping areas to
make sure nothing is mapped at specific addresses.
Thanks for taking a look!
--
Mike Kravetz
