[RFC v2 1/7] atomics: Add test for atomic operations with _relaxed variants

From: Boqun Feng
Date: Wed Sep 16 2015 - 11:52:52 EST


Some atomic operations now have _{relaxed, acquire, release} variants,
this patch then adds some trivial tests for two purpose:

1. test the behavior of these new operations in single-CPU
environment.
2. make their code generated before we actually use them somewhere,
so that we can examine their assembly code.

Signed-off-by: Boqun Feng <boqun.feng@xxxxxxxxx>
---
lib/atomic64_test.c | 91 ++++++++++++++++++++++++++++++++++-------------------
1 file changed, 59 insertions(+), 32 deletions(-)

diff --git a/lib/atomic64_test.c b/lib/atomic64_test.c
index 83c33a5b..0484437 100644
--- a/lib/atomic64_test.c
+++ b/lib/atomic64_test.c
@@ -27,6 +27,50 @@ do { \
(unsigned long long)r); \
} while (0)

+#define TEST_RETURN(bit, op, c_op, val) \
+do { \
+ atomic##bit##_set(&v, v0); \
+ r = v0; \
+ r c_op val; \
+ BUG_ON(atomic##bit##_##op(val, &v) != r); \
+ BUG_ON(atomic##bit##_read(&v) != r); \
+} while (0)
+
+#define TEST_RETURN_FAMILY(bit, op, c_op, val) \
+do { \
+ TEST_RETURN(bit, op, c_op, val); \
+ TEST_RETURN(bit, op##_acquire, c_op, val); \
+ TEST_RETURN(bit, op##_release, c_op, val); \
+ TEST_RETURN(bit, op##_relaxed, c_op, val); \
+} while (0)
+
+#define TEST_ARGS(bit, op, init, ret, expect, args...) \
+do { \
+ atomic##bit##_set(&v, init); \
+ BUG_ON(atomic##bit##_##op(&v, args) != ret); \
+ BUG_ON(atomic##bit##_read(&v) != expect); \
+} while (0)
+
+#define TEST_XCHG_FAMILY(bit, init, new) \
+do { \
+ TEST_ARGS(bit, xchg, init, init, new, new); \
+ TEST_ARGS(bit, xchg_acquire, init, init, new, new); \
+ TEST_ARGS(bit, xchg_release, init, init, new, new); \
+ TEST_ARGS(bit, xchg_relaxed, init, init, new, new); \
+} while (0)
+
+#define TEST_CMPXCHG_FAMILY(bit, init, new, wrong) \
+do { \
+ TEST_ARGS(bit, cmpxchg, init, init, new, init, new); \
+ TEST_ARGS(bit, cmpxchg, init, init, init, wrong, new); \
+ TEST_ARGS(bit, cmpxchg_acquire, init, init, new, init, new); \
+ TEST_ARGS(bit, cmpxchg_acquire, init, init, init, wrong, new); \
+ TEST_ARGS(bit, cmpxchg_release, init, init, new, init, new); \
+ TEST_ARGS(bit, cmpxchg_release, init, init, init, wrong, new); \
+ TEST_ARGS(bit, cmpxchg_relaxed, init, init, new, init, new); \
+ TEST_ARGS(bit, cmpxchg_relaxed, init, init, init, wrong, new); \
+} while (0)
+
static __init void test_atomic(void)
{
int v0 = 0xaaa31337;
@@ -45,6 +89,15 @@ static __init void test_atomic(void)
TEST(, and, &=, v1);
TEST(, xor, ^=, v1);
TEST(, andnot, &= ~, v1);
+
+ TEST_RETURN_FAMILY(, add_return, +=, onestwos);
+ TEST_RETURN_FAMILY(, add_return, +=, -one);
+ TEST_RETURN_FAMILY(, sub_return, -=, onestwos);
+ TEST_RETURN_FAMILY(, sub_return, -=, -one);
+
+ TEST_XCHG_FAMILY(, v0, v1);
+ TEST_CMPXCHG_FAMILY(, v0, v1, onestwos);
+
}

#define INIT(c) do { atomic64_set(&v, c); r = c; } while (0)
@@ -74,25 +127,10 @@ static __init void test_atomic64(void)
TEST(64, xor, ^=, v1);
TEST(64, andnot, &= ~, v1);

- INIT(v0);
- r += onestwos;
- BUG_ON(atomic64_add_return(onestwos, &v) != r);
- BUG_ON(v.counter != r);
-
- INIT(v0);
- r += -one;
- BUG_ON(atomic64_add_return(-one, &v) != r);
- BUG_ON(v.counter != r);
-
- INIT(v0);
- r -= onestwos;
- BUG_ON(atomic64_sub_return(onestwos, &v) != r);
- BUG_ON(v.counter != r);
-
- INIT(v0);
- r -= -one;
- BUG_ON(atomic64_sub_return(-one, &v) != r);
- BUG_ON(v.counter != r);
+ TEST_RETURN_FAMILY(64, add_return, +=, onestwos);
+ TEST_RETURN_FAMILY(64, add_return, +=, -one);
+ TEST_RETURN_FAMILY(64, sub_return, -=, onestwos);
+ TEST_RETURN_FAMILY(64, sub_return, -=, -one);

INIT(v0);
atomic64_inc(&v);
@@ -114,19 +152,8 @@ static __init void test_atomic64(void)
BUG_ON(atomic64_dec_return(&v) != r);
BUG_ON(v.counter != r);

- INIT(v0);
- BUG_ON(atomic64_xchg(&v, v1) != v0);
- r = v1;
- BUG_ON(v.counter != r);
-
- INIT(v0);
- BUG_ON(atomic64_cmpxchg(&v, v0, v1) != v0);
- r = v1;
- BUG_ON(v.counter != r);
-
- INIT(v0);
- BUG_ON(atomic64_cmpxchg(&v, v2, v1) != v0);
- BUG_ON(v.counter != r);
+ TEST_XCHG_FAMILY(64, v0, v1);
+ TEST_CMPXCHG_FAMILY(64, v0, v1, v2);

INIT(v0);
BUG_ON(atomic64_add_unless(&v, one, v0));
--
2.5.1

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