Re: [PATCH 6.1.y] selftests/mm: Move default_huge_page_size to vm_util.c

[Lance Yang <lance.yang@linux.dev>]

+Cc: Greg

On 2025/10/22 13:51, Leon Hwang wrote:
> Fix the build error:
> 
> map_hugetlb.c: In function 'main':
> map_hugetlb.c:79:25: warning: implicit declaration of function 'default_huge_page_size' [-Wimplicit-function-declaration]
>     79 |         hugepage_size = default_huge_page_size();
>        |                         ^~~~~~~~~~~~~~~~~~~~~~
> /usr/bin/ld: /tmp/ccYOogvJ.o: in function 'main':
> map_hugetlb.c:(.text+0x114): undefined reference to 'default_huge_page_size'
> 
> According to the latest selftests, 'default_huge_page_size' has been
> moved to 'vm_util.c'. So fix the error by the same way.
> 
> Reviewed-by: Lance Yang <lance.yang@linux.dev>
> Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
> ---
>   tools/testing/selftests/vm/Makefile      |  1 +
>   tools/testing/selftests/vm/userfaultfd.c | 24 ------------------------
>   tools/testing/selftests/vm/vm_util.c     | 21 +++++++++++++++++++++
>   tools/testing/selftests/vm/vm_util.h     |  1 +
>   4 files changed, 23 insertions(+), 24 deletions(-)
> 
> diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile
> index 192ea3725c5c..ed90deebef0d 100644
> --- a/tools/testing/selftests/vm/Makefile
> +++ b/tools/testing/selftests/vm/Makefile
> @@ -100,6 +100,7 @@ $(OUTPUT)/madv_populate: vm_util.c
>   $(OUTPUT)/soft-dirty: vm_util.c
>   $(OUTPUT)/split_huge_page_test: vm_util.c
>   $(OUTPUT)/userfaultfd: vm_util.c
> +$(OUTPUT)/map_hugetlb: vm_util.c
>   
>   ifeq ($(MACHINE),x86_64)
>   BINARIES_32 := $(patsubst %,$(OUTPUT)/%,$(BINARIES_32))
> diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
> index 297f250c1d95..4751b28eba18 100644
> --- a/tools/testing/selftests/vm/userfaultfd.c
> +++ b/tools/testing/selftests/vm/userfaultfd.c
> @@ -1674,30 +1674,6 @@ static int userfaultfd_stress(void)
>   		|| userfaultfd_events_test() || userfaultfd_minor_test();
>   }
>   
> -/*
> - * 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;
> -}
> -
>   static void set_test_type(const char *type)
>   {
>   	if (!strcmp(type, "anon")) {
> diff --git a/tools/testing/selftests/vm/vm_util.c b/tools/testing/selftests/vm/vm_util.c
> index fc5743bc1283..613cc61602c9 100644
> --- a/tools/testing/selftests/vm/vm_util.c
> +++ b/tools/testing/selftests/vm/vm_util.c
> @@ -161,6 +161,27 @@ bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size)
>   	return __check_huge(addr, "ShmemPmdMapped:", nr_hpages, hpage_size);
>   }
>   
> +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;
> +}
> +
>   static bool check_vmflag(void *addr, const char *flag)
>   {
>   	char buffer[MAX_LINE_LENGTH];
> diff --git a/tools/testing/selftests/vm/vm_util.h b/tools/testing/selftests/vm/vm_util.h
> index 470f85fe9594..a4439db0d6f8 100644
> --- a/tools/testing/selftests/vm/vm_util.h
> +++ b/tools/testing/selftests/vm/vm_util.h
> @@ -11,4 +11,5 @@ uint64_t read_pmd_pagesize(void);
>   bool check_huge_anon(void *addr, int nr_hpages, uint64_t hpage_size);
>   bool check_huge_file(void *addr, int nr_hpages, uint64_t hpage_size);
>   bool check_huge_shmem(void *addr, int nr_hpages, uint64_t hpage_size);
> +unsigned long default_huge_page_size(void);
>   bool softdirty_supported(void);