1 | // SPDX-License-Identifier: GPL-2.0 |
2 | #include "tests/tests.h" |
3 | #include "cloexec.h" |
4 | #include "debug.h" |
5 | #include "evlist.h" |
6 | #include "evsel.h" |
7 | #include "arch-tests.h" |
8 | #include <internal/lib.h> // page_size |
9 | |
10 | #include <signal.h> |
11 | #include <sys/mman.h> |
12 | #include <sys/wait.h> |
13 | #include <errno.h> |
14 | #include <string.h> |
15 | |
16 | static pid_t spawn(void) |
17 | { |
18 | pid_t pid; |
19 | |
20 | pid = fork(); |
21 | if (pid) |
22 | return pid; |
23 | |
24 | while(1) |
25 | sleep(5); |
26 | return 0; |
27 | } |
28 | |
29 | /* |
30 | * Create an event group that contains both a sampled hardware |
31 | * (cpu-cycles) and software (intel_cqm/llc_occupancy/) event. We then |
32 | * wait for the hardware perf counter to overflow and generate a PMI, |
33 | * which triggers an event read for both of the events in the group. |
34 | * |
35 | * Since reading Intel CQM event counters requires sending SMP IPIs, the |
36 | * CQM pmu needs to handle the above situation gracefully, and return |
37 | * the last read counter value to avoid triggering a WARN_ON_ONCE() in |
38 | * smp_call_function_many() caused by sending IPIs from NMI context. |
39 | */ |
40 | int test__intel_cqm_count_nmi_context(struct test_suite *test __maybe_unused, int subtest __maybe_unused) |
41 | { |
42 | struct evlist *evlist = NULL; |
43 | struct evsel *evsel = NULL; |
44 | struct perf_event_attr pe; |
45 | int i, fd[2], flag, ret; |
46 | size_t mmap_len; |
47 | void *event; |
48 | pid_t pid; |
49 | int err = TEST_FAIL; |
50 | |
51 | flag = perf_event_open_cloexec_flag(); |
52 | |
53 | evlist = evlist__new(); |
54 | if (!evlist) { |
55 | pr_debug("evlist__new failed\n" ); |
56 | return TEST_FAIL; |
57 | } |
58 | |
59 | ret = parse_event(evlist, "intel_cqm/llc_occupancy/" ); |
60 | if (ret) { |
61 | pr_debug("parse_events failed, is \"intel_cqm/llc_occupancy/\" available?\n" ); |
62 | err = TEST_SKIP; |
63 | goto out; |
64 | } |
65 | |
66 | evsel = evlist__first(evlist); |
67 | if (!evsel) { |
68 | pr_debug("evlist__first failed\n" ); |
69 | goto out; |
70 | } |
71 | |
72 | memset(&pe, 0, sizeof(pe)); |
73 | pe.size = sizeof(pe); |
74 | |
75 | pe.type = PERF_TYPE_HARDWARE; |
76 | pe.config = PERF_COUNT_HW_CPU_CYCLES; |
77 | pe.read_format = PERF_FORMAT_GROUP; |
78 | |
79 | pe.sample_period = 128; |
80 | pe.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_READ; |
81 | |
82 | pid = spawn(); |
83 | |
84 | fd[0] = sys_perf_event_open(&pe, pid, -1, -1, flag); |
85 | if (fd[0] < 0) { |
86 | pr_debug("failed to open event\n" ); |
87 | goto out; |
88 | } |
89 | |
90 | memset(&pe, 0, sizeof(pe)); |
91 | pe.size = sizeof(pe); |
92 | |
93 | pe.type = evsel->attr.type; |
94 | pe.config = evsel->attr.config; |
95 | |
96 | fd[1] = sys_perf_event_open(&pe, pid, -1, fd[0], flag); |
97 | if (fd[1] < 0) { |
98 | pr_debug("failed to open event\n" ); |
99 | goto out; |
100 | } |
101 | |
102 | /* |
103 | * Pick a power-of-two number of pages + 1 for the meta-data |
104 | * page (struct perf_event_mmap_page). See tools/perf/design.txt. |
105 | */ |
106 | mmap_len = page_size * 65; |
107 | |
108 | event = mmap(NULL, mmap_len, PROT_READ, MAP_SHARED, fd[0], 0); |
109 | if (event == (void *)(-1)) { |
110 | pr_debug("failed to mmap %d\n" , errno); |
111 | goto out; |
112 | } |
113 | |
114 | sleep(1); |
115 | |
116 | err = TEST_OK; |
117 | |
118 | munmap(event, mmap_len); |
119 | |
120 | for (i = 0; i < 2; i++) |
121 | close(fd[i]); |
122 | |
123 | kill(pid, SIGKILL); |
124 | wait(NULL); |
125 | out: |
126 | evlist__delete(evlist); |
127 | return err; |
128 | } |
129 | |