Test for_each_numa_cpus() output to ensure that:
- all CPUs are picked from NUMA nodes with non-decreasing distances to the
original node;
- only online CPUs are enumerated;
- the macro enumerates each online CPUs only once;
- enumeration order is consistent with cpumask_local_spread().
The latter is an implementation-defined behavior. If cpumask_local_spread()
or for_each_numa_cpu() will get changed in future, the subtest may need
to be adjusted or even removed, as appropriate.
It's useful now because some architectures don't implement numa_distance(),
and generic implementation only distinguishes local and remote nodes, which
doesn't allow to test the for_each_numa_cpu() properly.
Suggested-by: Valentin Schneider <vschneid@xxxxxxxxxx> (for node_distance() test)
Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
---
lib/test_bitmap.c | 70 +++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 68 insertions(+), 2 deletions(-)
diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index a8005ad3bd58..ac4fe621d37b 100644
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -12,6 +12,7 @@
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/string.h>
+#include <linux/topology.h>
#include <linux/uaccess.h>
#include "../tools/testing/selftests/kselftest_module.h"
@@ -71,6 +72,16 @@ __check_eq_uint(const char *srcfile, unsigned int line,
return true;
}
+static bool __init
+__check_ge_uint(const char *srcfile, unsigned int line,
+ const unsigned int exp_uint, unsigned int x)
+{
+ if (exp_uint >= x)
+ return true;
+
+ pr_err("[%s:%u] expected >= %u, got %u\n", srcfile, line, exp_uint, x);
+ return false;
+}
static bool __init
__check_eq_bitmap(const char *srcfile, unsigned int line,
@@ -86,6 +97,18 @@ __check_eq_bitmap(const char *srcfile, unsigned int line,
return true;
}
+static bool __init
+__check_eq_cpumask(const char *srcfile, unsigned int line,
+ const struct cpumask *exp_cpumask, const struct cpumask *cpumask)
+{
+ if (cpumask_equal(exp_cpumask, cpumask))
+ return true;
+
+ pr_warn("[%s:%u] cpumasks contents differ: expected \"%*pbl\", got \"%*pbl\"\n",
+ srcfile, line, cpumask_pr_args(exp_cpumask), cpumask_pr_args(cpumask));
+ return false;
+}
+
static bool __init
__check_eq_pbl(const char *srcfile, unsigned int line,
const char *expected_pbl,
@@ -173,11 +196,11 @@ __check_eq_str(const char *srcfile, unsigned int line,
return eq;
}
-#define __expect_eq(suffix, ...) \
+#define __expect(suffix, ...) \
({ \
int result = 0; \
total_tests++; \
- if (!__check_eq_ ## suffix(__FILE__, __LINE__, \
+ if (!__check_ ## suffix(__FILE__, __LINE__, \
##__VA_ARGS__)) { \
failed_tests++; \
result = 1; \
@@ -185,13 +208,19 @@ __check_eq_str(const char *srcfile, unsigned int line,
result; \
})
+#define __expect_eq(suffix, ...) __expect(eq_ ## suffix, ##__VA_ARGS__)
+#define __expect_ge(suffix, ...) __expect(ge_ ## suffix, ##__VA_ARGS__)
+
#define expect_eq_uint(...) __expect_eq(uint, ##__VA_ARGS__)
#define expect_eq_bitmap(...) __expect_eq(bitmap, ##__VA_ARGS__)
+#define expect_eq_cpumask(...) __expect_eq(cpumask, ##__VA_ARGS__)
#define expect_eq_pbl(...) __expect_eq(pbl, ##__VA_ARGS__)
#define expect_eq_u32_array(...) __expect_eq(u32_array, ##__VA_ARGS__)
#define expect_eq_clump8(...) __expect_eq(clump8, ##__VA_ARGS__)
#define expect_eq_str(...) __expect_eq(str, ##__VA_ARGS__)
+#define expect_ge_uint(...) __expect_ge(uint, ##__VA_ARGS__)
+
static void __init test_zero_clear(void)
{
DECLARE_BITMAP(bmap, 1024);
@@ -751,6 +780,42 @@ static void __init test_for_each_set_bit_wrap(void)
}
}
+static void __init test_for_each_numa_cpu(void)
+{
+ unsigned int node, cpu, hop;
+ cpumask_var_t mask;
+
+ if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
+ pr_err("Can't allocate cpumask. Skipping for_each_numa_cpu() test");
+ return;
+ }
+
+ for_each_node(node) {
+ unsigned int c = 0, dist, old_dist = node_distance(node, node);
+
+ cpumask_clear(mask);
+
+ rcu_read_lock();
+ for_each_numa_cpu(cpu, hop, node, cpu_possible_mask) {
+ dist = node_distance(cpu_to_node(cpu), node);
+
+ /* Distance between nodes must never decrease */
+ expect_ge_uint(dist, old_dist);
+
+ /* Test for coherence with cpumask_local_spread() */
+ expect_eq_uint(cpumask_local_spread(c++, node), cpu);
+
+ cpumask_set_cpu(cpu, mask);
+ old_dist = dist;
+ }
+ rcu_read_unlock();
+
+ /* Each online CPU must be visited exactly once */
+ expect_eq_uint(c, num_online_cpus());
+ expect_eq_cpumask(mask, cpu_online_mask);
+ }
+}
+
static void __init test_for_each_set_bit(void)
{
DECLARE_BITMAP(orig, 500);
@@ -1237,6 +1302,7 @@ static void __init selftest(void)
test_for_each_clear_bitrange_from();
test_for_each_set_clump8();
test_for_each_set_bit_wrap();
+ test_for_each_numa_cpu();
}
KSTM_MODULE_LOADERS(test_bitmap);
--
2.37.2
