selftests/mm: migration: add setup of HugeTLB pages

migration skips HugeTLB tests if there are no free huge pages prepared by
a wrapper script.

Add setup of HugeTLB pages to the test and make sure that the original
settings are restored on the test exit.

Since kselftest_harness runs fixture setup and the tests in child
processes, use HUGETLB_SETUP_DEFAULT_PAGES() that defines a constructor
that runs in the main process and add verification that there are enough
free huge pages to the tests that use them.

Reset signal handlers to defaults in FIXTURE_SETUP() so that sending
SIGTERM and SIGHUP during the tests won't cause restoration of HugeTLB
settings.

Link: https://lore.kernel.org/20260511162840.375890-46-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Tested-by: Luiz Capitulino <luizcap@redhat.com>
Tested-by: Sarthak Sharma <sarthak.sharma@arm.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Liam Howlett <liam@infradead.org>
Cc: Li Wang <li.wang@linux.dev>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/tools/testing/selftests/mm/migration.c b/tools/testing/selftests/mm/migration.c
index 7781a59bb9f81d49a40f2bfe5a8c3a743d374df9..29f7492453d4394c57cb320ec5d22d6fbd241ead 100644 (file)
--- a/tools/testing/selftests/mm/migration.c
+++ b/tools/testing/selftests/mm/migration.c
@@ -23,6 +23,8 @@
 #define MAX_RETRIES    100
 #define ALIGN(x, a)    (((x) + (a - 1)) & (~((a) - 1)))
 
+HUGETLB_SETUP_DEFAULT_PAGES(1)
+
 FIXTURE(migration)
 {
        pthread_t *threads;
@@ -32,10 +34,23 @@ FIXTURE(migration)
        int n2;
 };
 
+static void reset_signals(void)
+{
+       struct sigaction sa = { .sa_handler = SIG_DFL };
+
+       sigemptyset(&sa.sa_mask);
+       sigaction(SIGTERM, &sa, NULL);
+       sigaction(SIGHUP, &sa, NULL);
+       sigaction(SIGINT, &sa, NULL);
+       sigaction(SIGQUIT, &sa, NULL);
+}
+
 FIXTURE_SETUP(migration)
 {
        int n;
 
+       reset_signals();
+
        if (numa_available() < 0)
                SKIP(return, "NUMA not available");
        self->nthreads = numa_num_task_cpus() - 2;
@@ -288,6 +303,9 @@ TEST_F_TIMEOUT(migration, private_anon_htlb, 2*RUNTIME)
        if (!hugepage_size)
                SKIP(return, "Reading HugeTLB pagesize failed");
 
+       if (hugetlb_free_default_pages() < 1)
+               SKIP(return, "Not enough huge pages");
+
        ptr = mmap(NULL, hugepage_size, PROT_READ | PROT_WRITE,
                MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0);
        ASSERT_NE(ptr, MAP_FAILED);
@@ -316,6 +334,9 @@ TEST_F_TIMEOUT(migration, shared_anon_htlb, 2*RUNTIME)
        if (!hugepage_size)
                SKIP(return, "Reading HugeTLB pagesize failed");
 
+       if (hugetlb_free_default_pages() < 1)
+               SKIP(return, "Not enough huge pages");
+
        ptr = mmap(NULL, hugepage_size, PROT_READ | PROT_WRITE,
                MAP_SHARED | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0);
        ASSERT_NE(ptr, MAP_FAILED);