resctrl.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef RESCTRL_H
  3#define RESCTRL_H
  4#include <stdio.h>
  5#include <math.h>
  6#include <errno.h>
  7#include <sched.h>
  8#include <stdlib.h>
  9#include <unistd.h>
 10#include <string.h>
 11#include <signal.h>
 12#include <dirent.h>
 13#include <stdbool.h>
 14#include <ctype.h>
 15#include <sys/stat.h>
 16#include <sys/ioctl.h>
 17#include <sys/mount.h>
 18#include <sys/types.h>
 19#include <sys/wait.h>
 20#include <sys/select.h>
 21#include <sys/time.h>
 22#include <sys/eventfd.h>
 23#include <asm/unistd.h>
 24#include <linux/perf_event.h>
 25#include <linux/compiler.h>
 26#include "kselftest.h"
 27
 28#define MB			(1024 * 1024)
 29#define RESCTRL_PATH		"/sys/fs/resctrl"
 30#define PHYS_ID_PATH		"/sys/devices/system/cpu/cpu"
 31#define INFO_PATH		"/sys/fs/resctrl/info"
 32
 33/*
 34 * CPU vendor IDs
 35 *
 36 * Define as bits because they're used for vendor_specific bitmask in
 37 * the struct resctrl_test.
 38 */
 39#define ARCH_INTEL     1
 40#define ARCH_AMD       2
 41
 42#define END_OF_TESTS	1
 43
 44#define BENCHMARK_ARGS		64
 45
 46#define MINIMUM_SPAN		(250 * MB)
 47
 48/*
 49 * Memory bandwidth (in MiB) below which the bandwidth comparisons
 50 * between iMC and resctrl are considered unreliable. For example RAS
 51 * features or memory performance features that generate memory traffic
 52 * may drive accesses that are counted differently by performance counters
 53 * and MBM respectively, for instance generating "overhead" traffic which
 54 * is not counted against any specific RMID.
 55 */
 56#define THROTTLE_THRESHOLD	750
 57
 58/*
 59 * fill_buf_param:	"fill_buf" benchmark parameters
 60 * @buf_size:		Size (in bytes) of buffer used in benchmark.
 61 *			"fill_buf" allocates and initializes buffer of
 62 *			@buf_size. User can change value via command line.
 63 * @memflush:		If false the buffer will not be flushed after
 64 *			allocation and initialization, otherwise the
 65 *			buffer will be flushed. User can change value via
 66 *			command line (via integers with 0 interpreted as
 67 *			false and anything else as true).
 68 */
 69struct fill_buf_param {
 70	size_t		buf_size;
 71	bool		memflush;
 72};
 73
 74/*
 75 * user_params:		User supplied parameters
 76 * @cpu:		CPU number to which the benchmark will be bound to
 77 * @bits:		Number of bits used for cache allocation size
 78 * @benchmark_cmd:	Benchmark command to run during (some of the) tests
 79 * @fill_buf:		Pointer to user provided parameters for "fill_buf",
 80 *			NULL if user did not provide parameters and test
 81 *			specific defaults should be used.
 82 */
 83struct user_params {
 84	int cpu;
 85	int bits;
 86	const char *benchmark_cmd[BENCHMARK_ARGS];
 87	const struct fill_buf_param *fill_buf;
 88};
 89
 90/*
 91 * resctrl_test:	resctrl test definition
 92 * @name:		Test name
 93 * @group:		Test group - a common name for tests that share some characteristic
 94 *			(e.g., L3 CAT test belongs to the CAT group). Can be NULL
 95 * @resource:		Resource to test (e.g., MB, L3, L2, etc.)
 96 * @vendor_specific:	Bitmask for vendor-specific tests (can be 0 for universal tests)
 97 * @disabled:		Test is disabled
 98 * @feature_check:	Callback to check required resctrl features
 99 * @run_test:		Callback to run the test
100 * @cleanup:		Callback to cleanup after the test
101 */
102struct resctrl_test {
103	const char	*name;
104	const char	*group;
105	const char	*resource;
106	unsigned int	vendor_specific;
107	bool		disabled;
108	bool		(*feature_check)(const struct resctrl_test *test);
109	int		(*run_test)(const struct resctrl_test *test,
110				    const struct user_params *uparams);
111	void		(*cleanup)(void);
112};
113
114/*
115 * resctrl_val_param:	resctrl test parameters
116 * @ctrlgrp:		Name of the control monitor group (con_mon grp)
117 * @mongrp:		Name of the monitor group (mon grp)
118 * @filename:		Name of file to which the o/p should be written
119 * @init:		Callback function to initialize test environment
120 * @setup:		Callback function to setup per test run environment
121 * @measure:		Callback that performs the measurement (a single test)
122 * @fill_buf:		Parameters for default "fill_buf" benchmark.
123 *			Initialized with user provided parameters, possibly
124 *			adapted to be relevant to the test. If user does
125 *			not provide parameters for "fill_buf" nor a
126 *			replacement benchmark then initialized with defaults
127 *			appropriate for test. NULL if user provided
128 *			benchmark.
129 */
130struct resctrl_val_param {
131	const char		*ctrlgrp;
132	const char		*mongrp;
133	char			filename[64];
134	unsigned long		mask;
135	int			num_of_runs;
136	int			(*init)(const struct resctrl_val_param *param,
137					int domain_id);
138	int			(*setup)(const struct resctrl_test *test,
139					 const struct user_params *uparams,
140					 struct resctrl_val_param *param);
141	int			(*measure)(const struct user_params *uparams,
142					   struct resctrl_val_param *param,
143					   pid_t bm_pid);
144	struct fill_buf_param	*fill_buf;
145};
146
147struct perf_event_read {
148	__u64 nr;			/* The number of events */
149	struct {
150		__u64 value;		/* The value of the event */
151	} values[2];
152};
153
154/*
155 * Memory location that consumes values compiler must not optimize away.
156 * Volatile ensures writes to this location cannot be optimized away by
157 * compiler.
158 */
159extern volatile int *value_sink;
160
161extern int snc_unreliable;
162
163extern char llc_occup_path[1024];
164
165int snc_nodes_per_l3_cache(void);
166int get_vendor(void);
167bool check_resctrlfs_support(void);
168int filter_dmesg(void);
169int get_domain_id(const char *resource, int cpu_no, int *domain_id);
170int mount_resctrlfs(void);
171int umount_resctrlfs(void);
172bool resctrl_resource_exists(const char *resource);
173bool resctrl_mon_feature_exists(const char *resource, const char *feature);
174bool resource_info_file_exists(const char *resource, const char *file);
175bool test_resource_feature_check(const struct resctrl_test *test);
176char *fgrep(FILE *inf, const char *str);
177int taskset_benchmark(pid_t bm_pid, int cpu_no, cpu_set_t *old_affinity);
178int taskset_restore(pid_t bm_pid, cpu_set_t *old_affinity);
179int write_schemata(const char *ctrlgrp, char *schemata, int cpu_no,
180		   const char *resource);
181int write_bm_pid_to_resctrl(pid_t bm_pid, const char *ctrlgrp, const char *mongrp);
182int perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu,
183		    int group_fd, unsigned long flags);
184unsigned char *alloc_buffer(size_t buf_size, bool memflush);
185void mem_flush(unsigned char *buf, size_t buf_size);
186void fill_cache_read(unsigned char *buf, size_t buf_size, bool once);
187ssize_t get_fill_buf_size(int cpu_no, const char *cache_type);
188int initialize_read_mem_bw_imc(void);
189int measure_read_mem_bw(const struct user_params *uparams,
190			struct resctrl_val_param *param, pid_t bm_pid);
191void initialize_mem_bw_resctrl(const struct resctrl_val_param *param,
192			       int domain_id);
193int resctrl_val(const struct resctrl_test *test,
194		const struct user_params *uparams,
195		struct resctrl_val_param *param);
196unsigned long create_bit_mask(unsigned int start, unsigned int len);
197unsigned int count_contiguous_bits(unsigned long val, unsigned int *start);
198int get_full_cbm(const char *cache_type, unsigned long *mask);
199int get_mask_no_shareable(const char *cache_type, unsigned long *mask);
200int get_cache_size(int cpu_no, const char *cache_type, unsigned long *cache_size);
201int resource_info_unsigned_get(const char *resource, const char *filename, unsigned int *val);
202void ctrlc_handler(int signum, siginfo_t *info, void *ptr);
203int signal_handler_register(const struct resctrl_test *test);
204void signal_handler_unregister(void);
205unsigned int count_bits(unsigned long n);
206int snc_kernel_support(void);
207
208void perf_event_attr_initialize(struct perf_event_attr *pea, __u64 config);
209void perf_event_initialize_read_format(struct perf_event_read *pe_read);
210int perf_open(struct perf_event_attr *pea, pid_t pid, int cpu_no);
211int perf_event_reset_enable(int pe_fd);
212int perf_event_measure(int pe_fd, struct perf_event_read *pe_read,
213		       const char *filename, pid_t bm_pid);
214int measure_llc_resctrl(const char *filename, pid_t bm_pid);
215void show_cache_info(int no_of_bits, __u64 avg_llc_val, size_t cache_span, bool lines);
216
217/*
218 * cache_portion_size - Calculate the size of a cache portion
219 * @cache_size:		Total cache size in bytes
220 * @portion_mask:	Cache portion mask
221 * @full_cache_mask:	Full Cache Bit Mask (CBM) for the cache
222 *
223 * Return: The size of the cache portion in bytes.
224 */
225static inline unsigned long cache_portion_size(unsigned long cache_size,
226					       unsigned long portion_mask,
227					       unsigned long full_cache_mask)
228{
229	unsigned int bits = count_bits(full_cache_mask);
230
231	/*
232	 * With no bits the full CBM, assume cache cannot be split into
233	 * smaller portions. To avoid divide by zero, return cache_size.
234	 */
235	if (!bits)
236		return cache_size;
237
238	return cache_size * count_bits(portion_mask) / bits;
239}
240
241extern struct resctrl_test mbm_test;
242extern struct resctrl_test mba_test;
243extern struct resctrl_test cmt_test;
244extern struct resctrl_test l3_cat_test;
245extern struct resctrl_test l3_noncont_cat_test;
246extern struct resctrl_test l2_noncont_cat_test;
247
248#endif /* RESCTRL_H */