Commit 99babd04 authored by Mathieu Desnoyers's avatar Mathieu Desnoyers Committed by Peter Zijlstra
Browse files

selftests/rseq: Implement rseq numa node id field selftest 



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: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-7-mathieu.desnoyers@efficios.com
parent 03f5c027

tools/testing/selftests/rseq/basic_test.c

+4 −0
Original line number Diff line number Diff line
@@ -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 +31,8 @@ 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_id() == node);

			CPU_CLR(i, &test_affinity);

		}

	}

tools/testing/selftests/rseq/rseq-abi.h

+8 −0
Original line number Diff line number Diff line
@@ -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.

	 */

tools/testing/selftests/rseq/rseq.c

+18 −0
Original line number Diff line number Diff line
@@ -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 *cpu, unsigned *node)

{

	return syscall(__NR_getcpu, cpu, node, NULL);

}



int rseq_available(void)

{

	int rc;
@@ -201,3 +206,16 @@ 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;

}

tools/testing/selftests/rseq/rseq.h

+28 −0
Original line number Diff line number Diff line
@@ -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
@@ -128,6 +137,11 @@ 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).
@@ -163,6 +177,20 @@ static inline uint32_t rseq_current_cpu(void) 
	return cpu;

}



static inline bool rseq_node_id_available(void)

{

	return (int) rseq_feature_size >= rseq_offsetofend(struct rseq_abi, node_id);

}



/*

 * Current NUMA node number.

 */

static inline uint32_t rseq_current_node_id(void)

{

	assert(rseq_node_id_available());

	return RSEQ_ACCESS_ONCE(rseq_get_abi()->node_id);

}



static inline void rseq_clear_rseq_cs(void)

{

	RSEQ_WRITE_ONCE(rseq_get_abi()->rseq_cs.arch.ptr, 0);