Test the NUMA node id extension rseq field. Compare it against the value
returned by the getcpu(2) system call while pinned on a specific core.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
---
tools/testing/selftests/rseq/basic_test.c | 5 ++++
tools/testing/selftests/rseq/rseq-abi.h | 8 ++++++
tools/testing/selftests/rseq/rseq.c | 18 +++++++++++++
tools/testing/selftests/rseq/rseq.h | 31 +++++++++++++++++++++++
4 files changed, 62 insertions(+)
diff --git a/tools/testing/selftests/rseq/basic_test.c b/tools/testing/selftests/rseq/basic_test.c
index d8efbfb89193..a49b88cb20a3 100644
--- a/tools/testing/selftests/rseq/basic_test.c
+++ b/tools/testing/selftests/rseq/basic_test.c
@@ -22,6 +22,8 @@ void test_cpu_pointer(void)
CPU_ZERO(&test_affinity);
for (i = 0; i < CPU_SETSIZE; i++) {
if (CPU_ISSET(i, &affinity)) {
+ int node;
+
CPU_SET(i, &test_affinity);
sched_setaffinity(0, sizeof(test_affinity),
&test_affinity);
@@ -29,6 +31,9 @@ void test_cpu_pointer(void)
assert(rseq_current_cpu() == i);
assert(rseq_current_cpu_raw() == i);
assert(rseq_cpu_start() == i);
+ node = rseq_fallback_current_node();
+ assert(rseq_current_node() == node);
+ assert(rseq_current_node_raw() == node);
CPU_CLR(i, &test_affinity);
}
}
diff --git a/tools/testing/selftests/rseq/rseq-abi.h b/tools/testing/selftests/rseq/rseq-abi.h
index 00ac846d85b0..a1faa9162d52 100644
--- a/tools/testing/selftests/rseq/rseq-abi.h
+++ b/tools/testing/selftests/rseq/rseq-abi.h
@@ -147,6 +147,14 @@ struct rseq_abi {
*/
__u32 flags;
+ /*
+ * Restartable sequences node_id field. Updated by the kernel. Read by
+ * user-space with single-copy atomicity semantics. This field should
+ * only be read by the thread which registered this data structure.
+ * Aligned on 32-bit. Contains the current NUMA node ID.
+ */
+ __u32 node_id;
+
/*
* Flexible array member at end of structure, after last feature field.
*/
diff --git a/tools/testing/selftests/rseq/rseq.c b/tools/testing/selftests/rseq/rseq.c
index 506f2b17aea6..470fc0f73e22 100644
--- a/tools/testing/selftests/rseq/rseq.c
+++ b/tools/testing/selftests/rseq/rseq.c
@@ -79,6 +79,11 @@ static int sys_rseq(struct rseq_abi *rseq_abi, uint32_t rseq_len,
return syscall(__NR_rseq, rseq_abi, rseq_len, flags, sig);
}
+static int sys_getcpu(unsigned int *cpu, unsigned int *node)
+{
+ return syscall(__NR_getcpu, cpu, node, NULL);
+}
+
int rseq_available(void)
{
int rc;
@@ -199,3 +204,16 @@ int32_t rseq_fallback_current_cpu(void)
}
return cpu;
}
+
+int32_t rseq_fallback_current_node(void)
+{
+ uint32_t cpu_id, node_id;
+ int ret;
+
+ ret = sys_getcpu(&cpu_id, &node_id);
+ if (ret) {
+ perror("sys_getcpu()");
+ return ret;
+ }
+ return (int32_t) node_id;
+}
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index e73db2e82a11..4f1954cd12ff 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -20,6 +20,15 @@
#include "rseq-abi.h"
#include "compiler.h"
+#ifndef rseq_sizeof_field
+#define rseq_sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER))
+#endif
+
+#ifndef rseq_offsetofend
+#define rseq_offsetofend(TYPE, MEMBER) \
+ (offsetof(TYPE, MEMBER) + rseq_sizeof_field(TYPE, MEMBER))
+#endif
+
/*
* Empty code injection macros, override when testing.
* It is important to consider that the ASM injection macros need to be
@@ -123,6 +132,11 @@ int rseq_unregister_current_thread(void);
*/
int32_t rseq_fallback_current_cpu(void);
+/*
+ * Restartable sequence fallback for reading the current node number.
+ */
+int32_t rseq_fallback_current_node(void);
+
/*
* Values returned can be either the current CPU number, -1 (rseq is
* uninitialized), or -2 (rseq initialization has failed).
@@ -132,6 +146,15 @@ static inline int32_t rseq_current_cpu_raw(void)
return RSEQ_ACCESS_ONCE(rseq_get_abi()->cpu_id);
}
+/*
+ * Current NUMA node number.
+ */
+static inline uint32_t rseq_current_node_raw(void)
+{
+ assert((int) rseq_feature_size >= rseq_offsetofend(struct rseq_abi, node_id));
+ return RSEQ_ACCESS_ONCE(rseq_get_abi()->node_id);
+}
+
/*
* Returns a possible CPU number, which is typically the current CPU.
* The returned CPU number can be used to prepare for an rseq critical
@@ -158,6 +181,14 @@ static inline uint32_t rseq_current_cpu(void)
return cpu;
}
+static inline uint32_t rseq_current_node(void)
+{
+ if (rseq_likely((int) rseq_feature_size >= rseq_offsetofend(struct rseq_abi, node_id)))
+ return rseq_current_node_raw();
+ else
+ return rseq_fallback_current_node();
+}
+
static inline void rseq_clear_rseq_cs(void)
{
RSEQ_WRITE_ONCE(rseq_get_abi()->rseq_cs.arch.ptr, 0);
--
2.17.1
