1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2022. Huawei Technologies Co., Ltd */
3 #define _GNU_SOURCE
4 #include <sched.h>
5 #include <unistd.h>
6 #include <stdlib.h>
7 #include <stdbool.h>
8 #include <errno.h>
9 #include <string.h>
10 #include <pthread.h>
11
12 #include <bpf/bpf.h>
13 #include <bpf/libbpf.h>
14
15 #include "test_maps.h"
16 #include "task_local_storage_helpers.h"
17 #include "read_bpf_task_storage_busy.skel.h"
18
19 struct lookup_ctx {
20 bool start;
21 bool stop;
22 int pid_fd;
23 int map_fd;
24 int loop;
25 };
26
lookup_fn(void * arg)27 static void *lookup_fn(void *arg)
28 {
29 struct lookup_ctx *ctx = arg;
30 long value;
31 int i = 0;
32
33 while (!ctx->start)
34 usleep(1);
35
36 while (!ctx->stop && i++ < ctx->loop)
37 bpf_map_lookup_elem(ctx->map_fd, &ctx->pid_fd, &value);
38 return NULL;
39 }
40
abort_lookup(struct lookup_ctx * ctx,pthread_t * tids,unsigned int nr)41 static void abort_lookup(struct lookup_ctx *ctx, pthread_t *tids, unsigned int nr)
42 {
43 unsigned int i;
44
45 ctx->stop = true;
46 ctx->start = true;
47 for (i = 0; i < nr; i++)
48 pthread_join(tids[i], NULL);
49 }
50
test_task_storage_map_stress_lookup(void)51 void test_task_storage_map_stress_lookup(void)
52 {
53 #define MAX_NR_THREAD 4096
54 unsigned int i, nr = 256, loop = 8192, cpu = 0;
55 struct read_bpf_task_storage_busy *skel;
56 pthread_t tids[MAX_NR_THREAD];
57 struct lookup_ctx ctx;
58 cpu_set_t old, new;
59 const char *cfg;
60 int err;
61
62 cfg = getenv("TASK_STORAGE_MAP_NR_THREAD");
63 if (cfg) {
64 nr = atoi(cfg);
65 if (nr > MAX_NR_THREAD)
66 nr = MAX_NR_THREAD;
67 }
68 cfg = getenv("TASK_STORAGE_MAP_NR_LOOP");
69 if (cfg)
70 loop = atoi(cfg);
71 cfg = getenv("TASK_STORAGE_MAP_PIN_CPU");
72 if (cfg)
73 cpu = atoi(cfg);
74
75 skel = read_bpf_task_storage_busy__open_and_load();
76 err = libbpf_get_error(skel);
77 CHECK(err, "open_and_load", "error %d\n", err);
78
79 /* Only for a fully preemptible kernel */
80 if (!skel->kconfig->CONFIG_PREEMPT) {
81 printf("%s SKIP (no CONFIG_PREEMPT)\n", __func__);
82 read_bpf_task_storage_busy__destroy(skel);
83 skips++;
84 return;
85 }
86
87 /* Save the old affinity setting */
88 sched_getaffinity(getpid(), sizeof(old), &old);
89
90 /* Pinned on a specific CPU */
91 CPU_ZERO(&new);
92 CPU_SET(cpu, &new);
93 sched_setaffinity(getpid(), sizeof(new), &new);
94
95 ctx.start = false;
96 ctx.stop = false;
97 ctx.pid_fd = sys_pidfd_open(getpid(), 0);
98 ctx.map_fd = bpf_map__fd(skel->maps.task);
99 ctx.loop = loop;
100 for (i = 0; i < nr; i++) {
101 err = pthread_create(&tids[i], NULL, lookup_fn, &ctx);
102 if (err) {
103 abort_lookup(&ctx, tids, i);
104 CHECK(err, "pthread_create", "error %d\n", err);
105 goto out;
106 }
107 }
108
109 ctx.start = true;
110 for (i = 0; i < nr; i++)
111 pthread_join(tids[i], NULL);
112
113 skel->bss->pid = getpid();
114 err = read_bpf_task_storage_busy__attach(skel);
115 CHECK(err, "attach", "error %d\n", err);
116
117 /* Trigger program */
118 syscall(SYS_gettid);
119 skel->bss->pid = 0;
120
121 CHECK(skel->bss->busy != 0, "bad bpf_task_storage_busy", "got %d\n", skel->bss->busy);
122 out:
123 read_bpf_task_storage_busy__destroy(skel);
124 /* Restore affinity setting */
125 sched_setaffinity(getpid(), sizeof(old), &old);
126 printf("%s:PASS\n", __func__);
127 }
128