xref: /linux/tools/sched_ext/scx_qmap.c (revision bc8198dc7ebc492ec3e9fa1617dcdfbe98e73b17)
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 <bpf/bpf.h>
14 #include <scx/common.h>
15 #include "scx_qmap.bpf.skel.h"
16 
17 const char help_fmt[] =
18 "A simple five-level FIFO queue sched_ext scheduler.\n"
19 "\n"
20 "See the top-level comment in .bpf.c for more details.\n"
21 "\n"
22 "Usage: %s [-s SLICE_US] [-e COUNT] [-t COUNT] [-T COUNT] [-l COUNT] [-b COUNT]\n"
23 "       [-P] [-d PID] [-D LEN] [-p] [-v]\n"
24 "\n"
25 "  -s SLICE_US   Override slice duration\n"
26 "  -e COUNT      Trigger scx_bpf_error() after COUNT enqueues\n"
27 "  -t COUNT      Stall every COUNT'th user thread\n"
28 "  -T COUNT      Stall every COUNT'th kernel thread\n"
29 "  -l COUNT      Trigger dispatch infinite looping after COUNT dispatches\n"
30 "  -b COUNT      Dispatch upto COUNT tasks together\n"
31 "  -P            Print out DSQ content to trace_pipe every second, use with -b\n"
32 "  -H            Boost nice -20 tasks in SHARED_DSQ, use with -b\n"
33 "  -d PID        Disallow a process from switching into SCHED_EXT (-1 for self)\n"
34 "  -D LEN        Set scx_exit_info.dump buffer length\n"
35 "  -S            Suppress qmap-specific debug dump\n"
36 "  -p            Switch only tasks on SCHED_EXT policy instead of all\n"
37 "  -v            Print libbpf debug messages\n"
38 "  -h            Display this help and exit\n";
39 
40 static bool verbose;
41 static volatile int exit_req;
42 
43 static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
44 {
45 	if (level == LIBBPF_DEBUG && !verbose)
46 		return 0;
47 	return vfprintf(stderr, format, args);
48 }
49 
50 static void sigint_handler(int dummy)
51 {
52 	exit_req = 1;
53 }
54 
55 int main(int argc, char **argv)
56 {
57 	struct scx_qmap *skel;
58 	struct bpf_link *link;
59 	int opt;
60 
61 	libbpf_set_print(libbpf_print_fn);
62 	signal(SIGINT, sigint_handler);
63 	signal(SIGTERM, sigint_handler);
64 
65 	skel = SCX_OPS_OPEN(qmap_ops, scx_qmap);
66 
67 	skel->rodata->slice_ns = __COMPAT_ENUM_OR_ZERO("scx_public_consts", "SCX_SLICE_DFL");
68 
69 	while ((opt = getopt(argc, argv, "s:e:t:T:l:b:PHd:D:Spvh")) != -1) {
70 		switch (opt) {
71 		case 's':
72 			skel->rodata->slice_ns = strtoull(optarg, NULL, 0) * 1000;
73 			break;
74 		case 'e':
75 			skel->bss->test_error_cnt = strtoul(optarg, NULL, 0);
76 			break;
77 		case 't':
78 			skel->rodata->stall_user_nth = strtoul(optarg, NULL, 0);
79 			break;
80 		case 'T':
81 			skel->rodata->stall_kernel_nth = strtoul(optarg, NULL, 0);
82 			break;
83 		case 'l':
84 			skel->rodata->dsp_inf_loop_after = strtoul(optarg, NULL, 0);
85 			break;
86 		case 'b':
87 			skel->rodata->dsp_batch = strtoul(optarg, NULL, 0);
88 			break;
89 		case 'P':
90 			skel->rodata->print_shared_dsq = true;
91 			break;
92 		case 'H':
93 			skel->rodata->highpri_boosting = true;
94 			break;
95 		case 'd':
96 			skel->rodata->disallow_tgid = strtol(optarg, NULL, 0);
97 			if (skel->rodata->disallow_tgid < 0)
98 				skel->rodata->disallow_tgid = getpid();
99 			break;
100 		case 'D':
101 			skel->struct_ops.qmap_ops->exit_dump_len = strtoul(optarg, NULL, 0);
102 			break;
103 		case 'S':
104 			skel->rodata->suppress_dump = true;
105 			break;
106 		case 'p':
107 			skel->struct_ops.qmap_ops->flags |= SCX_OPS_SWITCH_PARTIAL;
108 			break;
109 		case 'v':
110 			verbose = true;
111 			break;
112 		default:
113 			fprintf(stderr, help_fmt, basename(argv[0]));
114 			return opt != 'h';
115 		}
116 	}
117 
118 	SCX_OPS_LOAD(skel, qmap_ops, scx_qmap, uei);
119 	link = SCX_OPS_ATTACH(skel, qmap_ops, scx_qmap);
120 
121 	while (!exit_req && !UEI_EXITED(skel, uei)) {
122 		long nr_enqueued = skel->bss->nr_enqueued;
123 		long nr_dispatched = skel->bss->nr_dispatched;
124 
125 		printf("stats  : enq=%lu dsp=%lu delta=%ld reenq=%"PRIu64" deq=%"PRIu64" core=%"PRIu64" enq_ddsp=%"PRIu64"\n",
126 		       nr_enqueued, nr_dispatched, nr_enqueued - nr_dispatched,
127 		       skel->bss->nr_reenqueued, skel->bss->nr_dequeued,
128 		       skel->bss->nr_core_sched_execed,
129 		       skel->bss->nr_ddsp_from_enq);
130 		printf("         exp_local=%"PRIu64" exp_remote=%"PRIu64" exp_timer=%"PRIu64" exp_lost=%"PRIu64"\n",
131 		       skel->bss->nr_expedited_local,
132 		       skel->bss->nr_expedited_remote,
133 		       skel->bss->nr_expedited_from_timer,
134 		       skel->bss->nr_expedited_lost);
135 		if (__COMPAT_has_ksym("scx_bpf_cpuperf_cur"))
136 			printf("cpuperf: cur min/avg/max=%u/%u/%u target min/avg/max=%u/%u/%u\n",
137 			       skel->bss->cpuperf_min,
138 			       skel->bss->cpuperf_avg,
139 			       skel->bss->cpuperf_max,
140 			       skel->bss->cpuperf_target_min,
141 			       skel->bss->cpuperf_target_avg,
142 			       skel->bss->cpuperf_target_max);
143 		fflush(stdout);
144 		sleep(1);
145 	}
146 
147 	bpf_link__destroy(link);
148 	UEI_REPORT(skel, uei);
149 	scx_qmap__destroy(skel);
150 	/*
151 	 * scx_qmap implements ops.cpu_on/offline() and doesn't need to restart
152 	 * on CPU hotplug events.
153 	 */
154 	return 0;
155 }
156