1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Cache Allocation Technology (CAT) test
4 *
5 * Copyright (C) 2018 Intel Corporation
6 *
7 * Authors:
8 * Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
9 * Fenghua Yu <fenghua.yu@intel.com>
10 */
11 #include "resctrl.h"
12 #include <unistd.h>
13
14 #define RESULT_FILE_NAME1 "result_cat1"
15 #define RESULT_FILE_NAME2 "result_cat2"
16 #define NUM_OF_RUNS 5
17 #define MAX_DIFF_PERCENT 4
18 #define MAX_DIFF 1000000
19
20 /*
21 * Change schemata. Write schemata to specified
22 * con_mon grp, mon_grp in resctrl FS.
23 * Run 5 times in order to get average values.
24 */
cat_setup(struct resctrl_val_param * p)25 static int cat_setup(struct resctrl_val_param *p)
26 {
27 char schemata[64];
28 int ret = 0;
29
30 /* Run NUM_OF_RUNS times */
31 if (p->num_of_runs >= NUM_OF_RUNS)
32 return END_OF_TESTS;
33
34 if (p->num_of_runs == 0) {
35 sprintf(schemata, "%lx", p->mask);
36 ret = write_schemata(p->ctrlgrp, schemata, p->cpu_no,
37 p->resctrl_val);
38 }
39 p->num_of_runs++;
40
41 return ret;
42 }
43
check_results(struct resctrl_val_param * param)44 static int check_results(struct resctrl_val_param *param)
45 {
46 char *token_array[8], temp[512];
47 unsigned long sum_llc_perf_miss = 0;
48 int runs = 0, no_of_bits = 0;
49 FILE *fp;
50
51 ksft_print_msg("Checking for pass/fail\n");
52 fp = fopen(param->filename, "r");
53 if (!fp) {
54 perror("# Cannot open file");
55
56 return errno;
57 }
58
59 while (fgets(temp, sizeof(temp), fp)) {
60 char *token = strtok(temp, ":\t");
61 int fields = 0;
62
63 while (token) {
64 token_array[fields++] = token;
65 token = strtok(NULL, ":\t");
66 }
67 /*
68 * Discard the first value which is inaccurate due to monitoring
69 * setup transition phase.
70 */
71 if (runs > 0)
72 sum_llc_perf_miss += strtoul(token_array[3], NULL, 0);
73 runs++;
74 }
75
76 fclose(fp);
77 no_of_bits = count_bits(param->mask);
78
79 return show_cache_info(sum_llc_perf_miss, no_of_bits, param->span / 64,
80 MAX_DIFF, MAX_DIFF_PERCENT, runs - 1,
81 get_vendor() == ARCH_INTEL, false);
82 }
83
cat_test_cleanup(void)84 void cat_test_cleanup(void)
85 {
86 remove(RESULT_FILE_NAME1);
87 remove(RESULT_FILE_NAME2);
88 }
89
cat_perf_miss_val(int cpu_no,int n,char * cache_type)90 int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
91 {
92 unsigned long l_mask, l_mask_1;
93 int ret, pipefd[2], sibling_cpu_no;
94 unsigned long cache_size = 0;
95 unsigned long long_mask;
96 char cbm_mask[256];
97 int count_of_bits;
98 char pipe_message;
99
100 /* Get default cbm mask for L3/L2 cache */
101 ret = get_cbm_mask(cache_type, cbm_mask);
102 if (ret)
103 return ret;
104
105 long_mask = strtoul(cbm_mask, NULL, 16);
106
107 /* Get L3/L2 cache size */
108 ret = get_cache_size(cpu_no, cache_type, &cache_size);
109 if (ret)
110 return ret;
111 ksft_print_msg("Cache size :%lu\n", cache_size);
112
113 /* Get max number of bits from default-cabm mask */
114 count_of_bits = count_bits(long_mask);
115
116 if (!n)
117 n = count_of_bits / 2;
118
119 if (n > count_of_bits - 1) {
120 ksft_print_msg("Invalid input value for no_of_bits n!\n");
121 ksft_print_msg("Please enter value in range 1 to %d\n",
122 count_of_bits - 1);
123 return -1;
124 }
125
126 /* Get core id from same socket for running another thread */
127 sibling_cpu_no = get_core_sibling(cpu_no);
128 if (sibling_cpu_no < 0)
129 return -1;
130
131 struct resctrl_val_param param = {
132 .resctrl_val = CAT_STR,
133 .cpu_no = cpu_no,
134 .setup = cat_setup,
135 };
136
137 l_mask = long_mask >> n;
138 l_mask_1 = ~l_mask & long_mask;
139
140 /* Set param values for parent thread which will be allocated bitmask
141 * with (max_bits - n) bits
142 */
143 param.span = cache_size * (count_of_bits - n) / count_of_bits;
144 strcpy(param.ctrlgrp, "c2");
145 strcpy(param.mongrp, "m2");
146 strcpy(param.filename, RESULT_FILE_NAME2);
147 param.mask = l_mask;
148 param.num_of_runs = 0;
149
150 if (pipe(pipefd)) {
151 perror("# Unable to create pipe");
152 return errno;
153 }
154
155 fflush(stdout);
156 bm_pid = fork();
157
158 /* Set param values for child thread which will be allocated bitmask
159 * with n bits
160 */
161 if (bm_pid == 0) {
162 param.mask = l_mask_1;
163 strcpy(param.ctrlgrp, "c1");
164 strcpy(param.mongrp, "m1");
165 param.span = cache_size * n / count_of_bits;
166 strcpy(param.filename, RESULT_FILE_NAME1);
167 param.num_of_runs = 0;
168 param.cpu_no = sibling_cpu_no;
169 } else {
170 ret = signal_handler_register();
171 if (ret) {
172 kill(bm_pid, SIGKILL);
173 goto out;
174 }
175 }
176
177 remove(param.filename);
178
179 ret = cat_val(¶m);
180 if (ret == 0)
181 ret = check_results(¶m);
182
183 if (bm_pid == 0) {
184 /* Tell parent that child is ready */
185 close(pipefd[0]);
186 pipe_message = 1;
187 if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <
188 sizeof(pipe_message))
189 /*
190 * Just print the error message.
191 * Let while(1) run and wait for itself to be killed.
192 */
193 perror("# failed signaling parent process");
194
195 close(pipefd[1]);
196 while (1)
197 ;
198 } else {
199 /* Parent waits for child to be ready. */
200 close(pipefd[1]);
201 pipe_message = 0;
202 while (pipe_message != 1) {
203 if (read(pipefd[0], &pipe_message,
204 sizeof(pipe_message)) < sizeof(pipe_message)) {
205 perror("# failed reading from child process");
206 break;
207 }
208 }
209 close(pipefd[0]);
210 kill(bm_pid, SIGKILL);
211 signal_handler_unregister();
212 }
213
214 out:
215 cat_test_cleanup();
216
217 return ret;
218 }
219
