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Date:   Mon, 5 Jun 2023 11:59:12 -0400
From:   Peter Xu <peterx@redhat.com>
To:     John Hubbard <jhubbard@nvidia.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        David Hildenbrand <david@redhat.com>,
        Shuah Khan <shuah@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>, linux-mm@kvack.org,
        linux-kselftest@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 10/11] selftests/mm: move uffd* routines from
 vm_util.c to uffd-common.c
Message-ID: <ZH4GUODwj9L9paey@x1n>
References: <20230603021558.95299-1-jhubbard@nvidia.com>
 <20230603021558.95299-11-jhubbard@nvidia.com>
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On Fri, Jun 02, 2023 at 07:15:57PM -0700, John Hubbard wrote:
> Move the uffd*() routines to their natural home. Note that
> ksm_functional_tests.c also depend, intentionally (due to a recent
> commit [1]), upon uffd-common.[ch].
> 
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Peter Xu <peterx@redhat.com>
> Signed-off-by: John Hubbard <jhubbard@nvidia.com>
> ---
>  tools/testing/selftests/mm/Makefile           |   7 +-
>  tools/testing/selftests/mm/hugepage-mremap.c  |   2 +-
>  .../selftests/mm/ksm_functional_tests.c       |   2 +-
>  tools/testing/selftests/mm/uffd-common.c      | 105 ++++++++++++++++++
>  tools/testing/selftests/mm/uffd-common.h      |  12 +-
>  tools/testing/selftests/mm/vm_util.c          | 104 -----------------
>  tools/testing/selftests/mm/vm_util.h          |  10 --
>  7 files changed, 122 insertions(+), 120 deletions(-)
> 
> diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
> index 23af4633f0f4..a15572758954 100644
> --- a/tools/testing/selftests/mm/Makefile
> +++ b/tools/testing/selftests/mm/Makefile
> @@ -109,8 +109,11 @@ include ../lib.mk
>  
>  $(TEST_GEN_PROGS): vm_util.c
>  
> -$(OUTPUT)/uffd-stress: uffd-common.c
> -$(OUTPUT)/uffd-unit-tests: uffd-common.c
> +$(OUTPUT)/uffd-stress:          uffd-common.c
> +$(OUTPUT)/uffd-unit-tests:      uffd-common.c
> +$(OUTPUT)/hugepage-mremap:      uffd-common.c
> +$(OUTPUT)/write_to_hugetlbfs:   uffd-common.c
> +$(OUTPUT)/ksm_functional_tests: uffd-common.c

Sorry, John, I still cannot follow..

As I said before uffd-common.[ch] was for uffd stress/unit tests.  I
confess my fault to not have named it uffd-test-common.[ch] already.

I think it's fine to keep uffd_*() helpers in vm_util.[ch] for now, until
it grows.  Just like if one day we'll have a pagemap.c test we don't
necessary need to move pagemap_*() helpers from vm_utils.[ch] into
pagemap.[ch].  It just keeps common test helpers.

Can we avoid linking those into other tests in whatever way?  Maybe
renaming it to uffd-test-common.[ch] may be cleaner?

-- 
Peter Xu