Re: [PATCH v2 9/9] memfd-test: run fuse test on hugetlb backend memory

["Marc-André Lureau" <marcandre.lureau@redhat.com>]

Hi

----- Original Message -----
> On 11/06/2017 06:39 AM, Marc-André Lureau wrote:
> > Suggested-by: Mike Kravetz <mike.kravetz@oracle.com>
> > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> > ---
> >  tools/testing/selftests/memfd/fuse_test.c      | 30
> >  ++++++++++++++++++++++----
> >  tools/testing/selftests/memfd/run_fuse_test.sh |  2 +-
> >  tools/testing/selftests/memfd/run_tests.sh     |  1 +
> >  3 files changed, 28 insertions(+), 5 deletions(-)
> > 
> > diff --git a/tools/testing/selftests/memfd/fuse_test.c
> > b/tools/testing/selftests/memfd/fuse_test.c
> > index 795a25ba8521..0a85b34929e1 100644
> > --- a/tools/testing/selftests/memfd/fuse_test.c
> > +++ b/tools/testing/selftests/memfd/fuse_test.c
> > @@ -38,6 +38,8 @@
> >  #define MFD_DEF_SIZE 8192
> >  #define STACK_SIZE 65536
> >  
> > +static size_t mfd_def_size = MFD_DEF_SIZE;
> > +
> >  static int mfd_assert_new(const char *name, loff_t sz, unsigned int flags)
> >  {
> >  	int r, fd;
> > @@ -123,7 +125,7 @@ static void *mfd_assert_mmap_shared(int fd)
> >  	void *p;
> >  
> >  	p = mmap(NULL,
> > -		 MFD_DEF_SIZE,
> > +		 mfd_def_size,
> >  		 PROT_READ | PROT_WRITE,
> >  		 MAP_SHARED,
> >  		 fd,
> > @@ -141,7 +143,7 @@ static void *mfd_assert_mmap_private(int fd)
> >  	void *p;
> >  
> >  	p = mmap(NULL,
> > -		 MFD_DEF_SIZE,
> > +		 mfd_def_size,
> >  		 PROT_READ | PROT_WRITE,
> >  		 MAP_PRIVATE,
> >  		 fd,
> > @@ -174,7 +176,7 @@ static int sealing_thread_fn(void *arg)
> >  	usleep(200000);
> >  
> >  	/* unmount mapping before sealing to avoid i_mmap_writable failures */
> > -	munmap(global_p, MFD_DEF_SIZE);
> > +	munmap(global_p, mfd_def_size);
> >  
> >  	/* Try sealing the global file; expect EBUSY or success. Current
> >  	 * kernels will never succeed, but in the future, kernels might
> > @@ -224,7 +226,7 @@ static void join_sealing_thread(pid_t pid)
> >  
> >  int main(int argc, char **argv)
> >  {
> > -	static const char zero[MFD_DEF_SIZE];
> > +	char *zero;
> >  	int fd, mfd, r;
> >  	void *p;
> >  	int was_sealed;
> > @@ -235,6 +237,25 @@ int main(int argc, char **argv)
> >  		abort();
> >  	}
> >  
> > +	if (argc >= 3) {
> > +		if (!strcmp(argv[2], "hugetlbfs")) {
> > +			unsigned long hpage_size = default_huge_page_size();
> > +
> > +			if (!hpage_size) {
> > +				printf("Unable to determine huge page size\n");
> > +				abort();
> > +			}
> > +
> > +			hugetlbfs_test = 1;
> > +			mfd_def_size = hpage_size * 2;
> > +		} else {
> > +			printf("Unknown option: %s\n", argv[2]);
> > +			abort();
> > +		}
> > +	}
> > +
> > +	zero = calloc(sizeof(*zero), mfd_def_size);
> > +
> >  	/* open FUSE memfd file for GUP testing */
> >  	printf("opening: %s\n", argv[1]);
> >  	fd = open(argv[1], O_RDONLY | O_CLOEXEC);
> 
> When ftruncate'ing the newly created file, you need to make sure length is
> a multiple of huge page size for hugetlbfs files.  So, you will want to
> do something like:
> 
> --- a/tools/testing/selftests/memfd/fuse_test.c
> +++ b/tools/testing/selftests/memfd/fuse_test.c
> @@ -265,7 +265,7 @@ int main(int argc, char **argv)
>  
>         /* create new memfd-object */
>         mfd = mfd_assert_new("kern_memfd_fuse",
> -                            MFD_DEF_SIZE,
> +                            mfd_def_size,
>                              MFD_CLOEXEC | MFD_ALLOW_SEALING);
>  
>         /* mmap memfd-object for writing */
> 
> Leaving MFD_DEF_SIZE for the size of reads and writes should be fine.

I actually intended to replace all MFD_DEF_SIZE with mfd_def_size. Should be fine too. Resending updated series.

> 
> --
> Mike Kravetz
> 
> > @@ -303,6 +324,7 @@ int main(int argc, char **argv)
> >  	close(fd);
> >  
> >  	printf("fuse: DONE\n");
> > +	free(zero);
> >  
> >  	return 0;
> >  }
> > diff --git a/tools/testing/selftests/memfd/run_fuse_test.sh
> > b/tools/testing/selftests/memfd/run_fuse_test.sh
> > index 407df68dfe27..22e572e2d66a 100755
> > --- a/tools/testing/selftests/memfd/run_fuse_test.sh
> > +++ b/tools/testing/selftests/memfd/run_fuse_test.sh
> > @@ -10,6 +10,6 @@ set -e
> >  
> >  mkdir mnt
> >  ./fuse_mnt ./mnt
> > -./fuse_test ./mnt/memfd
> > +./fuse_test ./mnt/memfd $@
> >  fusermount -u ./mnt
> >  rmdir ./mnt
> > diff --git a/tools/testing/selftests/memfd/run_tests.sh
> > b/tools/testing/selftests/memfd/run_tests.sh
> > index daabb350697c..c2d41ed81b24 100755
> > --- a/tools/testing/selftests/memfd/run_tests.sh
> > +++ b/tools/testing/selftests/memfd/run_tests.sh
> > @@ -60,6 +60,7 @@ fi
> >  # Run the hugetlbfs test
> >  #
> >  ./memfd_test hugetlbfs
> > +./run_fuse_test.sh hugetlbfs
> >  
> >  #
> >  # Give back any huge pages allocated for the test
> > 
> 
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