selftests/mm: hmm-tests: include linux/mman.h to access MADV_COLLAPSE

The following compilation error occurs with an old version of glibc due to
a recent commit adding MADV_COLLAPSE testing:

 [root@localhost mm]# getconf GNU_LIBC_VERSION
 glibc 2.34
 [root@localhost mm]# make
   CC       hmm-tests
 hmm-tests.c: In function 'hmm_migrate_anon_huge_fault':
 hmm-tests.c:2355:27: error: 'MADV_COLLAPSE' undeclared (first use in this function); did you mean 'MADV_COLD'?
  2355 |  ret = madvise(map, size, MADV_COLLAPSE);
       |                           ^~~~~~~~~~~~~
       |                           MADV_COLD
 hmm-tests.c:2355:27: note: each undeclared identifier is reported only once for each function it appears in
 make: *** [../lib.mk:225: /root/code/linux/tools/testing/selftests/mm/hmm-tests] Error 1

Include linux/mman.h (which provides the definition of MADV_COLLAPSE) to
fix the build error.

Link: https://lore.kernel.org/20260628143111.36863-1-zenghui.yu@linux.dev
Fixes: e3d8707358ea ("selftests/mm/hmm-tests: test pagemap reads of PMD device-private entries")
Signed-off-by: Zenghui Yu <zenghui.yu@linux.dev>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

0 files changed, 0 insertions, 0 deletions