On Mon, Dec 05, 2022, Vishal Annapurve wrote:
Add an API to query free 2MB hugepages in the system.
Signed-off-by: Vishal Annapurve vannapurve@google.com
.../testing/selftests/kvm/include/test_util.h | 1 + tools/testing/selftests/kvm/lib/test_util.c | 18 ++++++++++++++++++ 2 files changed, 19 insertions(+)
diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h index aea80071f2b8..3d1cc215940a 100644 --- a/tools/testing/selftests/kvm/include/test_util.h +++ b/tools/testing/selftests/kvm/include/test_util.h @@ -122,6 +122,7 @@ struct vm_mem_backing_src_alias { bool thp_configured(void); size_t get_trans_hugepagesz(void); size_t get_def_hugetlb_pagesz(void); +size_t get_free_huge_2mb_pages(void); const struct vm_mem_backing_src_alias *vm_mem_backing_src_alias(uint32_t i); size_t get_backing_src_pagesz(uint32_t i); bool is_backing_src_hugetlb(uint32_t i); diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c index d33b98bfe8a3..745573023b57 100644 --- a/tools/testing/selftests/kvm/lib/test_util.c +++ b/tools/testing/selftests/kvm/lib/test_util.c @@ -162,6 +162,24 @@ size_t get_trans_hugepagesz(void) return size; } +size_t get_free_huge_2mb_pages(void)
I strongly prefer to follow the precedence set by other tests, which at this point means defaulting to non-huge pages. I do think we need to make it easier and/or automatic to test hugepages, but I would like to tackle that problem separately. E.g. a kernel built without hugepage support will fail the fopen() below.
+{
- size_t free_pages;
- FILE *f;
- int ret;
- f = fopen("/sys/kernel/mm/hugepages/hugepages-2048kB/free_hugepages", "r");
- TEST_ASSERT(f != NULL, "Error in opening hugepages-2048kB/free_hugepages");
- do {
ret = fscanf(f, "%ld", &free_pages);
- } while (errno == EINTR);
- TEST_ASSERT(ret < 1, "Error reading hugepages-2048kB/free_hugepages");
- fclose(f);
- return free_pages;
+}
size_t get_def_hugetlb_pagesz(void) { char buf[64]; -- 2.39.0.rc0.267.gcb52ba06e7-goog