From 99babd04b25054717d21840298b0b46046b42cd9 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Tue, 22 Nov 2022 15:39:08 -0500 Subject: [PATCH] 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: Mathieu Desnoyers Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20221122203932.231377-7-mathieu.desnoyers@efficios.com --- tools/testing/selftests/rseq/basic_test.c | 4 ++++ tools/testing/selftests/rseq/rseq-abi.h | 8 +++++++ tools/testing/selftests/rseq/rseq.c | 18 +++++++++++++++ tools/testing/selftests/rseq/rseq.h | 28 +++++++++++++++++++++++ 4 files changed, 58 insertions(+) diff --git a/tools/testing/selftests/rseq/basic_test.c b/tools/testing/selftests/rseq/basic_test.c index d8efbfb89193..295eea16466f 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 +31,8 @@ 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); } } 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 1e8e3265bdbf..4e4aa006004c 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 *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; +} diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h index 95adc1e1b0db..fd17d0e54a1b 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 @@ -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); -- 2.39.5