Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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
20static int count_of_bits;
21static char cbm_mask[256];
22static unsigned long long_mask;
23static unsigned long cache_size;
24
25/*
26 * Change schemata. Write schemata to specified
27 * con_mon grp, mon_grp in resctrl FS.
28 * Run 5 times in order to get average values.
29 */
30static int cat_setup(int num, ...)
31{
32 struct resctrl_val_param *p;
33 char schemata[64];
34 va_list param;
35 int ret = 0;
36
37 va_start(param, num);
38 p = va_arg(param, struct resctrl_val_param *);
39 va_end(param);
40
41 /* Run NUM_OF_RUNS times */
42 if (p->num_of_runs >= NUM_OF_RUNS)
43 return END_OF_TESTS;
44
45 if (p->num_of_runs == 0) {
46 sprintf(schemata, "%lx", p->mask);
47 ret = write_schemata(p->ctrlgrp, schemata, p->cpu_no,
48 p->resctrl_val);
49 }
50 p->num_of_runs++;
51
52 return ret;
53}
54
55static int check_results(struct resctrl_val_param *param)
56{
57 char *token_array[8], temp[512];
58 unsigned long sum_llc_perf_miss = 0;
59 int runs = 0, no_of_bits = 0;
60 FILE *fp;
61
62 ksft_print_msg("Checking for pass/fail\n");
63 fp = fopen(param->filename, "r");
64 if (!fp) {
65 perror("# Cannot open file");
66
67 return errno;
68 }
69
70 while (fgets(temp, sizeof(temp), fp)) {
71 char *token = strtok(temp, ":\t");
72 int fields = 0;
73
74 while (token) {
75 token_array[fields++] = token;
76 token = strtok(NULL, ":\t");
77 }
78 /*
79 * Discard the first value which is inaccurate due to monitoring
80 * setup transition phase.
81 */
82 if (runs > 0)
83 sum_llc_perf_miss += strtoul(token_array[3], NULL, 0);
84 runs++;
85 }
86
87 fclose(fp);
88 no_of_bits = count_bits(param->mask);
89
90 return show_cache_info(sum_llc_perf_miss, no_of_bits, param->span / 64,
91 MAX_DIFF, MAX_DIFF_PERCENT, NUM_OF_RUNS,
92 get_vendor() == ARCH_INTEL, false);
93}
94
95void cat_test_cleanup(void)
96{
97 remove(RESULT_FILE_NAME1);
98 remove(RESULT_FILE_NAME2);
99}
100
101int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
102{
103 unsigned long l_mask, l_mask_1;
104 int ret, pipefd[2], sibling_cpu_no;
105 char pipe_message;
106
107 cache_size = 0;
108
109 ret = remount_resctrlfs(true);
110 if (ret)
111 return ret;
112
113 /* Get default cbm mask for L3/L2 cache */
114 ret = get_cbm_mask(cache_type, cbm_mask);
115 if (ret)
116 return ret;
117
118 long_mask = strtoul(cbm_mask, NULL, 16);
119
120 /* Get L3/L2 cache size */
121 ret = get_cache_size(cpu_no, cache_type, &cache_size);
122 if (ret)
123 return ret;
124 ksft_print_msg("Cache size :%lu\n", cache_size);
125
126 /* Get max number of bits from default-cabm mask */
127 count_of_bits = count_bits(long_mask);
128
129 if (!n)
130 n = count_of_bits / 2;
131
132 if (n > count_of_bits - 1) {
133 ksft_print_msg("Invalid input value for no_of_bits n!\n");
134 ksft_print_msg("Please enter value in range 1 to %d\n",
135 count_of_bits - 1);
136 return -1;
137 }
138
139 /* Get core id from same socket for running another thread */
140 sibling_cpu_no = get_core_sibling(cpu_no);
141 if (sibling_cpu_no < 0)
142 return -1;
143
144 struct resctrl_val_param param = {
145 .resctrl_val = CAT_STR,
146 .cpu_no = cpu_no,
147 .mum_resctrlfs = false,
148 .setup = cat_setup,
149 };
150
151 l_mask = long_mask >> n;
152 l_mask_1 = ~l_mask & long_mask;
153
154 /* Set param values for parent thread which will be allocated bitmask
155 * with (max_bits - n) bits
156 */
157 param.span = cache_size * (count_of_bits - n) / count_of_bits;
158 strcpy(param.ctrlgrp, "c2");
159 strcpy(param.mongrp, "m2");
160 strcpy(param.filename, RESULT_FILE_NAME2);
161 param.mask = l_mask;
162 param.num_of_runs = 0;
163
164 if (pipe(pipefd)) {
165 perror("# Unable to create pipe");
166 return errno;
167 }
168
169 fflush(stdout);
170 bm_pid = fork();
171
172 /* Set param values for child thread which will be allocated bitmask
173 * with n bits
174 */
175 if (bm_pid == 0) {
176 param.mask = l_mask_1;
177 strcpy(param.ctrlgrp, "c1");
178 strcpy(param.mongrp, "m1");
179 param.span = cache_size * n / count_of_bits;
180 strcpy(param.filename, RESULT_FILE_NAME1);
181 param.num_of_runs = 0;
182 param.cpu_no = sibling_cpu_no;
183 } else {
184 ret = signal_handler_register();
185 if (ret) {
186 kill(bm_pid, SIGKILL);
187 goto out;
188 }
189 }
190
191 remove(param.filename);
192
193 ret = cat_val(¶m);
194 if (ret == 0)
195 ret = check_results(¶m);
196
197 if (bm_pid == 0) {
198 /* Tell parent that child is ready */
199 close(pipefd[0]);
200 pipe_message = 1;
201 if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <
202 sizeof(pipe_message))
203 /*
204 * Just print the error message.
205 * Let while(1) run and wait for itself to be killed.
206 */
207 perror("# failed signaling parent process");
208
209 close(pipefd[1]);
210 while (1)
211 ;
212 } else {
213 /* Parent waits for child to be ready. */
214 close(pipefd[1]);
215 pipe_message = 0;
216 while (pipe_message != 1) {
217 if (read(pipefd[0], &pipe_message,
218 sizeof(pipe_message)) < sizeof(pipe_message)) {
219 perror("# failed reading from child process");
220 break;
221 }
222 }
223 close(pipefd[0]);
224 kill(bm_pid, SIGKILL);
225 signal_handler_unregister();
226 }
227
228out:
229 cat_test_cleanup();
230 if (bm_pid)
231 umount_resctrlfs();
232
233 return ret;
234}