xref: /linux/tools/sched_ext/scx_qmap.c (revision aec2f682d47c54ef434b2d440992626d80b1ebdc)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
4  * Copyright (c) 2022 Tejun Heo <tj@kernel.org>
5  * Copyright (c) 2022 David Vernet <dvernet@meta.com>
6  */
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <unistd.h>
10 #include <inttypes.h>
11 #include <signal.h>
12 #include <libgen.h>
13 #include <sys/stat.h>
14 #include <bpf/bpf.h>
15 #include <scx/common.h>
16 #include "scx_qmap.bpf.skel.h"
17 
18 const char help_fmt[] =
19 "A simple five-level FIFO queue sched_ext scheduler.\n"
20 "\n"
21 "See the top-level comment in .bpf.c for more details.\n"
22 "\n"
23 "Usage: %s [-s SLICE_US] [-e COUNT] [-t COUNT] [-T COUNT] [-l COUNT] [-b COUNT]\n"
24 "       [-P] [-M] [-H] [-d PID] [-D LEN] [-S] [-p] [-I] [-F COUNT] [-v]\n"
25 "\n"
26 "  -s SLICE_US   Override slice duration\n"
27 "  -e COUNT      Trigger scx_bpf_error() after COUNT enqueues\n"
28 "  -t COUNT      Stall every COUNT'th user thread\n"
29 "  -T COUNT      Stall every COUNT'th kernel thread\n"
30 "  -l COUNT      Trigger dispatch infinite looping after COUNT dispatches\n"
31 "  -b COUNT      Dispatch upto COUNT tasks together\n"
32 "  -P            Print out DSQ content and event counters to trace_pipe every second\n"
33 "  -M            Print out debug messages to trace_pipe\n"
34 "  -H            Boost nice -20 tasks in SHARED_DSQ, use with -b\n"
35 "  -d PID        Disallow a process from switching into SCHED_EXT (-1 for self)\n"
36 "  -D LEN        Set scx_exit_info.dump buffer length\n"
37 "  -S            Suppress qmap-specific debug dump\n"
38 "  -p            Switch only tasks on SCHED_EXT policy instead of all\n"
39 "  -I            Turn on SCX_OPS_ALWAYS_ENQ_IMMED\n"
40 "  -F COUNT      IMMED stress: force every COUNT'th enqueue to a busy local DSQ (use with -I)\n"
41 "  -v            Print libbpf debug messages\n"
42 "  -h            Display this help and exit\n";
43 
44 static bool verbose;
45 static volatile int exit_req;
46 
47 static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
48 {
49 	if (level == LIBBPF_DEBUG && !verbose)
50 		return 0;
51 	return vfprintf(stderr, format, args);
52 }
53 
54 static void sigint_handler(int dummy)
55 {
56 	exit_req = 1;
57 }
58 
59 int main(int argc, char **argv)
60 {
61 	struct scx_qmap *skel;
62 	struct bpf_link *link;
63 	int opt;
64 
65 	libbpf_set_print(libbpf_print_fn);
66 	signal(SIGINT, sigint_handler);
67 	signal(SIGTERM, sigint_handler);
68 
69 	skel = SCX_OPS_OPEN(qmap_ops, scx_qmap);
70 
71 	skel->rodata->slice_ns = __COMPAT_ENUM_OR_ZERO("scx_public_consts", "SCX_SLICE_DFL");
72 
73 	while ((opt = getopt(argc, argv, "s:e:t:T:l:b:PMHc:d:D:SpIF:vh")) != -1) {
74 		switch (opt) {
75 		case 's':
76 			skel->rodata->slice_ns = strtoull(optarg, NULL, 0) * 1000;
77 			break;
78 		case 'e':
79 			skel->bss->test_error_cnt = strtoul(optarg, NULL, 0);
80 			break;
81 		case 't':
82 			skel->rodata->stall_user_nth = strtoul(optarg, NULL, 0);
83 			break;
84 		case 'T':
85 			skel->rodata->stall_kernel_nth = strtoul(optarg, NULL, 0);
86 			break;
87 		case 'l':
88 			skel->rodata->dsp_inf_loop_after = strtoul(optarg, NULL, 0);
89 			break;
90 		case 'b':
91 			skel->rodata->dsp_batch = strtoul(optarg, NULL, 0);
92 			break;
93 		case 'P':
94 			skel->rodata->print_dsqs_and_events = true;
95 			break;
96 		case 'M':
97 			skel->rodata->print_msgs = true;
98 			break;
99 		case 'H':
100 			skel->rodata->highpri_boosting = true;
101 			break;
102 		case 'c': {
103 			struct stat st;
104 			if (stat(optarg, &st) < 0) {
105 				perror("stat");
106 				return 1;
107 			}
108 			skel->struct_ops.qmap_ops->sub_cgroup_id = st.st_ino;
109 			skel->rodata->sub_cgroup_id = st.st_ino;
110 			break;
111 		}
112 		case 'd':
113 			skel->rodata->disallow_tgid = strtol(optarg, NULL, 0);
114 			if (skel->rodata->disallow_tgid < 0)
115 				skel->rodata->disallow_tgid = getpid();
116 			break;
117 		case 'D':
118 			skel->struct_ops.qmap_ops->exit_dump_len = strtoul(optarg, NULL, 0);
119 			break;
120 		case 'S':
121 			skel->rodata->suppress_dump = true;
122 			break;
123 		case 'p':
124 			skel->struct_ops.qmap_ops->flags |= SCX_OPS_SWITCH_PARTIAL;
125 			break;
126 		case 'I':
127 			skel->rodata->always_enq_immed = true;
128 			skel->struct_ops.qmap_ops->flags |= SCX_OPS_ALWAYS_ENQ_IMMED;
129 			break;
130 		case 'F':
131 			skel->rodata->immed_stress_nth = strtoul(optarg, NULL, 0);
132 			break;
133 		case 'v':
134 			verbose = true;
135 			break;
136 		default:
137 			fprintf(stderr, help_fmt, basename(argv[0]));
138 			return opt != 'h';
139 		}
140 	}
141 
142 	SCX_OPS_LOAD(skel, qmap_ops, scx_qmap, uei);
143 	link = SCX_OPS_ATTACH(skel, qmap_ops, scx_qmap);
144 
145 	while (!exit_req && !UEI_EXITED(skel, uei)) {
146 		long nr_enqueued = skel->bss->nr_enqueued;
147 		long nr_dispatched = skel->bss->nr_dispatched;
148 
149 		printf("stats  : enq=%lu dsp=%lu delta=%ld reenq/cpu0=%"PRIu64"/%"PRIu64" deq=%"PRIu64" core=%"PRIu64" enq_ddsp=%"PRIu64"\n",
150 		       nr_enqueued, nr_dispatched, nr_enqueued - nr_dispatched,
151 		       skel->bss->nr_reenqueued, skel->bss->nr_reenqueued_cpu0,
152 		       skel->bss->nr_dequeued,
153 		       skel->bss->nr_core_sched_execed,
154 		       skel->bss->nr_ddsp_from_enq);
155 		printf("         exp_local=%"PRIu64" exp_remote=%"PRIu64" exp_timer=%"PRIu64" exp_lost=%"PRIu64"\n",
156 		       skel->bss->nr_expedited_local,
157 		       skel->bss->nr_expedited_remote,
158 		       skel->bss->nr_expedited_from_timer,
159 		       skel->bss->nr_expedited_lost);
160 		if (__COMPAT_has_ksym("scx_bpf_cpuperf_cur"))
161 			printf("cpuperf: cur min/avg/max=%u/%u/%u target min/avg/max=%u/%u/%u\n",
162 			       skel->bss->cpuperf_min,
163 			       skel->bss->cpuperf_avg,
164 			       skel->bss->cpuperf_max,
165 			       skel->bss->cpuperf_target_min,
166 			       skel->bss->cpuperf_target_avg,
167 			       skel->bss->cpuperf_target_max);
168 		fflush(stdout);
169 		sleep(1);
170 	}
171 
172 	bpf_link__destroy(link);
173 	UEI_REPORT(skel, uei);
174 	scx_qmap__destroy(skel);
175 	/*
176 	 * scx_qmap implements ops.cpu_on/offline() and doesn't need to restart
177 	 * on CPU hotplug events.
178 	 */
179 	return 0;
180 }
181