1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <stdint.h>
4 #include "resctrl.h"
5
6 char llc_occup_path[1024];
7
perf_event_attr_initialize(struct perf_event_attr * pea,__u64 config)8 void perf_event_attr_initialize(struct perf_event_attr *pea, __u64 config)
9 {
10 memset(pea, 0, sizeof(*pea));
11 pea->type = PERF_TYPE_HARDWARE;
12 pea->size = sizeof(*pea);
13 pea->read_format = PERF_FORMAT_GROUP;
14 pea->exclude_kernel = 1;
15 pea->exclude_hv = 1;
16 pea->exclude_idle = 1;
17 pea->exclude_callchain_kernel = 1;
18 pea->inherit = 1;
19 pea->exclude_guest = 1;
20 pea->disabled = 1;
21 pea->config = config;
22 }
23
24 /* Start counters to log values */
perf_event_reset_enable(int pe_fd)25 int perf_event_reset_enable(int pe_fd)
26 {
27 int ret;
28
29 ret = ioctl(pe_fd, PERF_EVENT_IOC_RESET, 0);
30 if (ret < 0)
31 return ret;
32
33 ret = ioctl(pe_fd, PERF_EVENT_IOC_ENABLE, 0);
34 if (ret < 0)
35 return ret;
36
37 return 0;
38 }
39
perf_event_initialize_read_format(struct perf_event_read * pe_read)40 void perf_event_initialize_read_format(struct perf_event_read *pe_read)
41 {
42 memset(pe_read, 0, sizeof(*pe_read));
43 pe_read->nr = 1;
44 }
45
perf_open(struct perf_event_attr * pea,pid_t pid,int cpu_no)46 int perf_open(struct perf_event_attr *pea, pid_t pid, int cpu_no)
47 {
48 int pe_fd;
49
50 pe_fd = perf_event_open(pea, pid, cpu_no, -1, PERF_FLAG_FD_CLOEXEC);
51 if (pe_fd == -1) {
52 ksft_perror("Error opening leader");
53 return -1;
54 }
55
56 perf_event_reset_enable(pe_fd);
57
58 return pe_fd;
59 }
60
61 /*
62 * Get LLC Occupancy as reported by RESCTRL FS
63 * For CMT,
64 * 1. If con_mon grp and mon grp given, then read from mon grp in
65 * con_mon grp
66 * 2. If only con_mon grp given, then read from con_mon grp
67 * 3. If both not given, then read from root con_mon grp
68 * For CAT,
69 * 1. If con_mon grp given, then read from it
70 * 2. If con_mon grp not given, then read from root con_mon grp
71 *
72 * Return: =0 on success. <0 on failure.
73 */
get_llc_occu_resctrl(unsigned long * llc_occupancy)74 static int get_llc_occu_resctrl(unsigned long *llc_occupancy)
75 {
76 FILE *fp;
77
78 fp = fopen(llc_occup_path, "r");
79 if (!fp) {
80 ksft_perror("Failed to open results file");
81
82 return -1;
83 }
84 if (fscanf(fp, "%lu", llc_occupancy) <= 0) {
85 ksft_perror("Could not get llc occupancy");
86 fclose(fp);
87
88 return -1;
89 }
90 fclose(fp);
91
92 return 0;
93 }
94
95 /*
96 * print_results_cache: the cache results are stored in a file
97 * @filename: file that stores the results
98 * @bm_pid: child pid that runs benchmark
99 * @llc_value: perf miss value /
100 * llc occupancy value reported by resctrl FS
101 *
102 * Return: 0 on success, < 0 on error.
103 */
print_results_cache(const char * filename,pid_t bm_pid,__u64 llc_value)104 static int print_results_cache(const char *filename, pid_t bm_pid, __u64 llc_value)
105 {
106 FILE *fp;
107
108 if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) {
109 printf("Pid: %d \t LLC_value: %llu\n", (int)bm_pid, llc_value);
110 } else {
111 fp = fopen(filename, "a");
112 if (!fp) {
113 ksft_perror("Cannot open results file");
114
115 return -1;
116 }
117 fprintf(fp, "Pid: %d \t llc_value: %llu\n", (int)bm_pid, llc_value);
118 fclose(fp);
119 }
120
121 return 0;
122 }
123
124 /*
125 * perf_event_measure - Measure perf events
126 * @filename: Filename for writing the results
127 * @bm_pid: PID that runs the benchmark
128 *
129 * Measures perf events (e.g., cache misses) and writes the results into
130 * @filename. @bm_pid is written to the results file along with the measured
131 * value.
132 *
133 * Return: =0 on success. <0 on failure.
134 */
perf_event_measure(int pe_fd,struct perf_event_read * pe_read,const char * filename,pid_t bm_pid)135 int perf_event_measure(int pe_fd, struct perf_event_read *pe_read,
136 const char *filename, pid_t bm_pid)
137 {
138 int ret;
139
140 /* Stop counters after one span to get miss rate */
141 ret = ioctl(pe_fd, PERF_EVENT_IOC_DISABLE, 0);
142 if (ret < 0)
143 return ret;
144
145 ret = read(pe_fd, pe_read, sizeof(*pe_read));
146 if (ret == -1) {
147 ksft_perror("Could not get perf value");
148 return -1;
149 }
150
151 return print_results_cache(filename, bm_pid, pe_read->values[0].value);
152 }
153
154 /*
155 * measure_llc_resctrl - Measure resctrl LLC value from resctrl
156 * @filename: Filename for writing the results
157 * @bm_pid: PID that runs the benchmark
158 *
159 * Measures LLC occupancy from resctrl and writes the results into @filename.
160 * @bm_pid is written to the results file along with the measured value.
161 *
162 * Return: =0 on success. <0 on failure.
163 */
measure_llc_resctrl(const char * filename,pid_t bm_pid)164 int measure_llc_resctrl(const char *filename, pid_t bm_pid)
165 {
166 unsigned long llc_occu_resc = 0;
167 int ret;
168
169 ret = get_llc_occu_resctrl(&llc_occu_resc);
170 if (ret < 0)
171 return ret;
172
173 return print_results_cache(filename, bm_pid, llc_occu_resc);
174 }
175
176 /*
177 * show_cache_info - Show generic cache test information
178 * @no_of_bits: Number of bits
179 * @avg_llc_val: Average of LLC cache result data
180 * @cache_span: Cache span
181 * @lines: @cache_span in lines or bytes
182 */
show_cache_info(int no_of_bits,__u64 avg_llc_val,size_t cache_span,bool lines)183 void show_cache_info(int no_of_bits, __u64 avg_llc_val, size_t cache_span, bool lines)
184 {
185 ksft_print_msg("Number of bits: %d\n", no_of_bits);
186 ksft_print_msg("Average LLC val: %llu\n", avg_llc_val);
187 ksft_print_msg("Cache span (%s): %zu\n", lines ? "lines" : "bytes",
188 cache_span);
189 }
190