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Subject: Re: [PATCH 10/12] selftests/mm: move uffd* routines from vm_util.c to
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To:     Peter Xu <peterx@redhat.com>
CC:     Andrew Morton <akpm@linux-foundation.org>,
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From:   John Hubbard <jhubbard@nvidia.com>
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On 6/2/23 15:38, Peter Xu wrote:
...
>>> I'm fine to move it over if you think proper, but just to mention I had
>>> those in vm_utils.h just because I left all uffd specific tests shared code
>>> in uffd-common.h, so my plan was uffd-common.h shouldn't be included in
>>> most test cases except uffd tests.
>>
>> I think we're in agreement that we want to only include uffd-common.h
>> where it's actually required. Likewise with the uffd*() routines. So I
>> would like to still move this over, yes, just to have things in their
>> best-named location.
> 
> Sorry I didn't get it - e.g. I'm confused why we need to export
> uffd_test_ops into ksm unit test, it doesn't make much sense to me..

Oh, I see what you mean, finally. Yes. ksm should not need that.

> 
> If you think vm_util.h is a name too common to contain uffd helpers, shall

Right, given the presence of uffd-common.[chg], I really want to avoid putting
the uffd helpers somewhere else...

> we create another vm_util_uffd.h just to put the uffd helpers?
> 
> Just see what's there in uffd-common.h, which is still ugly (I could look
> into it some other day):

Good point.

> 
> extern unsigned long nr_cpus, nr_pages, nr_pages_per_cpu, page_size;
> extern char *area_src, *area_src_alias, *area_dst, *area_dst_alias, *area_remap;
> extern int uffd, uffd_flags, finished, *pipefd, test_type;
> extern bool map_shared;
> extern bool test_uffdio_wp;
> extern unsigned long long *count_verify;
> extern volatile bool test_uffdio_copy_eexist;
> 
> extern uffd_test_ops_t anon_uffd_test_ops;
> extern uffd_test_ops_t shmem_uffd_test_ops;
> extern uffd_test_ops_t hugetlb_uffd_test_ops;
> extern uffd_test_ops_t *uffd_test_ops;
> 
> and more.
> 
> That's why I think this header should not better be included by anyone else
> besides uffd-stress.c and uffd-unit-tests.c for now.
> 

OK, I think I can arrange things to meet that requirement. Let me
take another shot at it.


thanks,
-- 
John Hubbard
NVIDIA