The KSM NUMA merge test allocates identical pages on different NUMA
nodes and verifies KSM behavior with merge_across_nodes enabled and
disabled.
On systems with memoryless NUMA nodes, for example:
#numactl -H
available: 2 nodes (0,4)
.....
node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
node 0 size: 14825 MB
node 0 free: 1382 MB
node 4 cpus:
node 4 size: 0 MB
node 4 free: 0 MB
the test may attempt to allocate memory on a node without memory,
causing numa_alloc_onnode() to fail and resulting in a spurious test
failure.
Add count_mem_nodes() helper to count only nodes with memory and use it
instead of numa_num_configured_nodes() to ensure the test runs only on
systems with at least two NUMA nodes that have memory. Skip the test
otherwise.
Before patch:
---------------------------
running ./ksm_tests -N -m 1
---------------------------
mbind: Invalid argument
ok 1 KSM NUMA merging
Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0
[PASS]
ok 1 ksm_tests -N -m 1
---------------------------
running ./ksm_tests -N -m 0
---------------------------
mbind: Invalid argument
not ok 1 KSM NUMA merging
Totals: pass:0 fail:1 xfail:0 xpass:0 skip:0 error:0
[FAIL]
not ok 2 ksm_tests -N -m 0 # exit=1
After patch:
---------------------------
running ./ksm_tests -N -m 1
---------------------------
SKIP At least 2 NUMA nodes with memory must be available
Totals: pass:0 fail:0 xfail:0 xpass:0 skip:1 error:0
[SKIP]
ok 1 ksm_tests -N -m 1 # SKIP
---------------------------
running ./ksm_tests -N -m 0
---------------------------
SKIP At least 2 NUMA nodes with memory must be available
Totals: pass:0 fail:0 xfail:0 xpass:0 skip:1 error:0
[SKIP]
ok 2 ksm_tests -N -m 0 # SKIP
Fixes: e3820ab252dd ("selftest/vm: fix ksm selftest to run with different NUMA
topologies")
Signed-off-by: Sayali Patil <[email protected]>
---
tools/testing/selftests/mm/ksm_tests.c | 26 ++++++++++++++++++--------
1 file changed, 18 insertions(+), 8 deletions(-)
diff --git a/tools/testing/selftests/mm/ksm_tests.c
b/tools/testing/selftests/mm/ksm_tests.c
index a050f4840cfa..d1790b4347d3 100644
--- a/tools/testing/selftests/mm/ksm_tests.c
+++ b/tools/testing/selftests/mm/ksm_tests.c
@@ -450,6 +450,18 @@ static int get_first_mem_node(void)
return get_next_mem_node(numa_max_node());
}
+static int count_mem_nodes(void)
+{
+ int node, count = 0;
+
+ for (node = 0; node <= numa_max_node(); node++) {
+ if (numa_node_size(node, NULL) > 0)
+ count++;
+ }
+
+ return count;
+}
+
static int check_ksm_numa_merge(int merge_type, int mapping, int prot, int
timeout,
bool merge_across_nodes, size_t page_size)
{
@@ -463,14 +475,12 @@ static int check_ksm_numa_merge(int merge_type, int
mapping, int prot, int timeo
return KSFT_FAIL;
}
- if (numa_available() < 0) {
- ksft_print_msg("NUMA support not enabled\n");
- return KSFT_SKIP;
- }
- if (numa_num_configured_nodes() <= 1) {
- ksft_print_msg("At least 2 NUMA nodes must be available\n");
- return KSFT_SKIP;
- }
+ if (numa_available() < 0)
+ ksft_exit_skip("NUMA support not enabled\n");
+
+ if (count_mem_nodes() <= 1)
+ ksft_exit_skip("At least 2 NUMA nodes with memory must be
available\n");
+
if (ksm_write_sysfs(KSM_FP("merge_across_nodes"), merge_across_nodes))
return KSFT_FAIL;
--
2.52.0
