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2e24ce88 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
a241ec65 | 2 | /* |
29766f1e | 3 | * Read-Copy Update module-based torture test facility |
a241ec65 | 4 | * |
b772e1dd | 5 | * Copyright (C) IBM Corporation, 2005, 2006 |
a241ec65 | 6 | * |
2e24ce88 | 7 | * Authors: Paul E. McKenney <paulmck@linux.ibm.com> |
e0198b29 | 8 | * Josh Triplett <josh@joshtriplett.org> |
a241ec65 PM |
9 | * |
10 | * See also: Documentation/RCU/torture.txt | |
11 | */ | |
60500037 PM |
12 | |
13 | #define pr_fmt(fmt) fmt | |
14 | ||
a241ec65 PM |
15 | #include <linux/types.h> |
16 | #include <linux/kernel.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/kthread.h> | |
20 | #include <linux/err.h> | |
21 | #include <linux/spinlock.h> | |
22 | #include <linux/smp.h> | |
23 | #include <linux/rcupdate.h> | |
24 | #include <linux/interrupt.h> | |
174cd4b1 | 25 | #include <linux/sched/signal.h> |
ae7e81c0 | 26 | #include <uapi/linux/sched/types.h> |
60063497 | 27 | #include <linux/atomic.h> |
a241ec65 | 28 | #include <linux/bitops.h> |
a241ec65 PM |
29 | #include <linux/completion.h> |
30 | #include <linux/moduleparam.h> | |
31 | #include <linux/percpu.h> | |
32 | #include <linux/notifier.h> | |
343e9099 | 33 | #include <linux/reboot.h> |
83144186 | 34 | #include <linux/freezer.h> |
a241ec65 | 35 | #include <linux/cpu.h> |
a241ec65 | 36 | #include <linux/delay.h> |
a241ec65 | 37 | #include <linux/stat.h> |
b2896d2e | 38 | #include <linux/srcu.h> |
1aeb272c | 39 | #include <linux/slab.h> |
52494535 | 40 | #include <linux/trace_clock.h> |
f07767fd | 41 | #include <asm/byteorder.h> |
51b1130e | 42 | #include <linux/torture.h> |
38706bc5 | 43 | #include <linux/vmalloc.h> |
0032f4e8 | 44 | #include <linux/sched/debug.h> |
450efca7 | 45 | #include <linux/sched/sysctl.h> |
e0aff973 | 46 | #include <linux/oom.h> |
a241ec65 | 47 | |
25c36329 PM |
48 | #include "rcu.h" |
49 | ||
a241ec65 | 50 | MODULE_LICENSE("GPL"); |
2e24ce88 | 51 | MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com> and Josh Triplett <josh@joshtriplett.org>"); |
a241ec65 | 52 | |
4102adab | 53 | |
2397d072 PM |
54 | /* Bits for ->extendables field, extendables param, and related definitions. */ |
55 | #define RCUTORTURE_RDR_SHIFT 8 /* Put SRCU index in upper bits. */ | |
56 | #define RCUTORTURE_RDR_MASK ((1 << RCUTORTURE_RDR_SHIFT) - 1) | |
2ceebc03 PM |
57 | #define RCUTORTURE_RDR_BH 0x01 /* Extend readers by disabling bh. */ |
58 | #define RCUTORTURE_RDR_IRQ 0x02 /* ... disabling interrupts. */ | |
59 | #define RCUTORTURE_RDR_PREEMPT 0x04 /* ... disabling preemption. */ | |
60 | #define RCUTORTURE_RDR_RBH 0x08 /* ... rcu_read_lock_bh(). */ | |
61 | #define RCUTORTURE_RDR_SCHED 0x10 /* ... rcu_read_lock_sched(). */ | |
62 | #define RCUTORTURE_RDR_RCU 0x20 /* ... entering another RCU reader. */ | |
63 | #define RCUTORTURE_RDR_NBITS 6 /* Number of bits defined above. */ | |
64 | #define RCUTORTURE_MAX_EXTEND \ | |
65 | (RCUTORTURE_RDR_BH | RCUTORTURE_RDR_IRQ | RCUTORTURE_RDR_PREEMPT | \ | |
66 | RCUTORTURE_RDR_RBH | RCUTORTURE_RDR_SCHED) | |
2397d072 PM |
67 | #define RCUTORTURE_RDR_MAX_LOOPS 0x7 /* Maximum reader extensions. */ |
68 | /* Must be power of two minus one. */ | |
c116dba6 | 69 | #define RCUTORTURE_RDR_MAX_SEGS (RCUTORTURE_RDR_MAX_LOOPS + 3) |
2397d072 | 70 | |
2397d072 PM |
71 | torture_param(int, extendables, RCUTORTURE_MAX_EXTEND, |
72 | "Extend readers by disabling bh (1), irqs (2), or preempt (4)"); | |
9e250225 PM |
73 | torture_param(int, fqs_duration, 0, |
74 | "Duration of fqs bursts (us), 0 to disable"); | |
75 | torture_param(int, fqs_holdoff, 0, "Holdoff time within fqs bursts (us)"); | |
76 | torture_param(int, fqs_stutter, 3, "Wait time between fqs bursts (s)"); | |
1b27291b PM |
77 | torture_param(bool, fwd_progress, 1, "Test grace-period forward progress"); |
78 | torture_param(int, fwd_progress_div, 4, "Fraction of CPU stall to wait"); | |
79 | torture_param(int, fwd_progress_holdoff, 60, | |
80 | "Time between forward-progress tests (s)"); | |
81 | torture_param(bool, fwd_progress_need_resched, 1, | |
82 | "Hide cond_resched() behind need_resched()"); | |
a48f3fad | 83 | torture_param(bool, gp_cond, false, "Use conditional/async GP wait primitives"); |
9e250225 PM |
84 | torture_param(bool, gp_exp, false, "Use expedited GP wait primitives"); |
85 | torture_param(bool, gp_normal, false, | |
86 | "Use normal (non-expedited) GP wait primitives"); | |
f0bf8fab | 87 | torture_param(bool, gp_sync, false, "Use synchronous GP wait primitives"); |
9e250225 PM |
88 | torture_param(int, irqreader, 1, "Allow RCU readers from irq handlers"); |
89 | torture_param(int, n_barrier_cbs, 0, | |
90 | "# of callbacks/kthreads for barrier testing"); | |
91 | torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads"); | |
92 | torture_param(int, nreaders, -1, "Number of RCU reader threads"); | |
93 | torture_param(int, object_debug, 0, | |
94 | "Enable debug-object double call_rcu() testing"); | |
95 | torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)"); | |
96 | torture_param(int, onoff_interval, 0, | |
028be12b | 97 | "Time between CPU hotplugs (jiffies), 0=disable"); |
9e250225 PM |
98 | torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles"); |
99 | torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable."); | |
100 | torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable."); | |
101 | torture_param(int, stall_cpu_holdoff, 10, | |
102 | "Time to wait before starting stall (s)."); | |
2b1516e5 | 103 | torture_param(int, stall_cpu_irqsoff, 0, "Disable interrupts while stalling."); |
9e250225 PM |
104 | torture_param(int, stat_interval, 60, |
105 | "Number of seconds between stats printk()s"); | |
106 | torture_param(int, stutter, 5, "Number of seconds to run/halt test"); | |
107 | torture_param(int, test_boost, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes."); | |
108 | torture_param(int, test_boost_duration, 4, | |
109 | "Duration of each boost test, seconds."); | |
110 | torture_param(int, test_boost_interval, 7, | |
111 | "Interval between boost tests, seconds."); | |
112 | torture_param(bool, test_no_idle_hz, true, | |
113 | "Test support for tickless idle CPUs"); | |
90127d60 | 114 | torture_param(int, verbose, 1, |
b5daa8f3 | 115 | "Enable verbose debugging printk()s"); |
9e250225 | 116 | |
d10453e9 | 117 | static char *torture_type = "rcu"; |
d6ad6711 | 118 | module_param(torture_type, charp, 0444); |
c770c82a | 119 | MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, srcu, ...)"); |
a241ec65 | 120 | |
a241ec65 PM |
121 | static int nrealreaders; |
122 | static struct task_struct *writer_task; | |
b772e1dd | 123 | static struct task_struct **fakewriter_tasks; |
a241ec65 PM |
124 | static struct task_struct **reader_tasks; |
125 | static struct task_struct *stats_task; | |
bf66f18e | 126 | static struct task_struct *fqs_task; |
8e8be45e | 127 | static struct task_struct *boost_tasks[NR_CPUS]; |
c13f3757 | 128 | static struct task_struct *stall_task; |
1b27291b | 129 | static struct task_struct *fwd_prog_task; |
fae4b54f PM |
130 | static struct task_struct **barrier_cbs_tasks; |
131 | static struct task_struct *barrier_task; | |
a241ec65 PM |
132 | |
133 | #define RCU_TORTURE_PIPE_LEN 10 | |
134 | ||
135 | struct rcu_torture { | |
136 | struct rcu_head rtort_rcu; | |
137 | int rtort_pipe_count; | |
138 | struct list_head rtort_free; | |
996417d2 | 139 | int rtort_mbtest; |
a241ec65 PM |
140 | }; |
141 | ||
a241ec65 | 142 | static LIST_HEAD(rcu_torture_freelist); |
0ddea0ea | 143 | static struct rcu_torture __rcu *rcu_torture_current; |
4a298656 | 144 | static unsigned long rcu_torture_current_version; |
a241ec65 PM |
145 | static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; |
146 | static DEFINE_SPINLOCK(rcu_torture_lock); | |
67522bee PM |
147 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count); |
148 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch); | |
a241ec65 | 149 | static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; |
b2896d2e PM |
150 | static atomic_t n_rcu_torture_alloc; |
151 | static atomic_t n_rcu_torture_alloc_fail; | |
152 | static atomic_t n_rcu_torture_free; | |
153 | static atomic_t n_rcu_torture_mberror; | |
154 | static atomic_t n_rcu_torture_error; | |
fae4b54f | 155 | static long n_rcu_torture_barrier_error; |
8e8be45e PM |
156 | static long n_rcu_torture_boost_ktrerror; |
157 | static long n_rcu_torture_boost_rterror; | |
8e8be45e PM |
158 | static long n_rcu_torture_boost_failure; |
159 | static long n_rcu_torture_boosts; | |
8da9a595 | 160 | static atomic_long_t n_rcu_torture_timers; |
fae4b54f | 161 | static long n_barrier_attempts; |
bf5b6435 | 162 | static long n_barrier_successes; /* did rcu_barrier test succeed? */ |
e3033736 | 163 | static struct list_head rcu_torture_removed; |
60013d5d | 164 | static unsigned long shutdown_jiffies; |
d120f65f | 165 | |
ad0dc7f9 PM |
166 | static int rcu_torture_writer_state; |
167 | #define RTWS_FIXED_DELAY 0 | |
168 | #define RTWS_DELAY 1 | |
169 | #define RTWS_REPLACE 2 | |
170 | #define RTWS_DEF_FREE 3 | |
171 | #define RTWS_EXP_SYNC 4 | |
a48f3fad PM |
172 | #define RTWS_COND_GET 5 |
173 | #define RTWS_COND_SYNC 6 | |
f0bf8fab PM |
174 | #define RTWS_SYNC 7 |
175 | #define RTWS_STUTTER 8 | |
176 | #define RTWS_STOPPING 9 | |
18aff33e PM |
177 | static const char * const rcu_torture_writer_state_names[] = { |
178 | "RTWS_FIXED_DELAY", | |
179 | "RTWS_DELAY", | |
180 | "RTWS_REPLACE", | |
181 | "RTWS_DEF_FREE", | |
182 | "RTWS_EXP_SYNC", | |
183 | "RTWS_COND_GET", | |
184 | "RTWS_COND_SYNC", | |
185 | "RTWS_SYNC", | |
186 | "RTWS_STUTTER", | |
187 | "RTWS_STOPPING", | |
188 | }; | |
189 | ||
c116dba6 PM |
190 | /* Record reader segment types and duration for first failing read. */ |
191 | struct rt_read_seg { | |
192 | int rt_readstate; | |
193 | unsigned long rt_delay_jiffies; | |
194 | unsigned long rt_delay_ms; | |
195 | unsigned long rt_delay_us; | |
196 | bool rt_preempted; | |
197 | }; | |
198 | static int err_segs_recorded; | |
199 | static struct rt_read_seg err_segs[RCUTORTURE_RDR_MAX_SEGS]; | |
200 | static int rt_read_nsegs; | |
201 | ||
18aff33e PM |
202 | static const char *rcu_torture_writer_state_getname(void) |
203 | { | |
204 | unsigned int i = READ_ONCE(rcu_torture_writer_state); | |
205 | ||
206 | if (i >= ARRAY_SIZE(rcu_torture_writer_state_names)) | |
207 | return "???"; | |
208 | return rcu_torture_writer_state_names[i]; | |
209 | } | |
ad0dc7f9 | 210 | |
3acf4a9a | 211 | #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) |
8e8be45e | 212 | #define rcu_can_boost() 1 |
3acf4a9a | 213 | #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ |
8e8be45e | 214 | #define rcu_can_boost() 0 |
3acf4a9a | 215 | #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ |
8e8be45e | 216 | |
e4aa0da3 SR |
217 | #ifdef CONFIG_RCU_TRACE |
218 | static u64 notrace rcu_trace_clock_local(void) | |
219 | { | |
220 | u64 ts = trace_clock_local(); | |
a3b7b6c2 PM |
221 | |
222 | (void)do_div(ts, NSEC_PER_USEC); | |
e4aa0da3 SR |
223 | return ts; |
224 | } | |
225 | #else /* #ifdef CONFIG_RCU_TRACE */ | |
226 | static u64 notrace rcu_trace_clock_local(void) | |
227 | { | |
228 | return 0ULL; | |
229 | } | |
230 | #endif /* #else #ifdef CONFIG_RCU_TRACE */ | |
231 | ||
60013d5d PM |
232 | /* |
233 | * Stop aggressive CPU-hog tests a bit before the end of the test in order | |
234 | * to avoid interfering with test shutdown. | |
235 | */ | |
236 | static bool shutdown_time_arrived(void) | |
237 | { | |
238 | return shutdown_secs && time_after(jiffies, shutdown_jiffies - 30 * HZ); | |
239 | } | |
240 | ||
8e8be45e | 241 | static unsigned long boost_starttime; /* jiffies of next boost test start. */ |
58ade2db | 242 | static DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */ |
8e8be45e | 243 | /* and boost task create/destroy. */ |
fae4b54f | 244 | static atomic_t barrier_cbs_count; /* Barrier callbacks registered. */ |
c6ebcbb6 | 245 | static bool barrier_phase; /* Test phase. */ |
fae4b54f PM |
246 | static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */ |
247 | static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */ | |
248 | static DECLARE_WAIT_QUEUE_HEAD(barrier_wq); | |
8e8be45e | 249 | |
48718485 PM |
250 | static bool rcu_fwd_cb_nodelay; /* Short rcu_torture_delay() delays. */ |
251 | ||
a241ec65 PM |
252 | /* |
253 | * Allocate an element from the rcu_tortures pool. | |
254 | */ | |
97a41e26 | 255 | static struct rcu_torture * |
a241ec65 PM |
256 | rcu_torture_alloc(void) |
257 | { | |
258 | struct list_head *p; | |
259 | ||
adac1665 | 260 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 PM |
261 | if (list_empty(&rcu_torture_freelist)) { |
262 | atomic_inc(&n_rcu_torture_alloc_fail); | |
adac1665 | 263 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
264 | return NULL; |
265 | } | |
266 | atomic_inc(&n_rcu_torture_alloc); | |
267 | p = rcu_torture_freelist.next; | |
268 | list_del_init(p); | |
adac1665 | 269 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
270 | return container_of(p, struct rcu_torture, rtort_free); |
271 | } | |
272 | ||
273 | /* | |
274 | * Free an element to the rcu_tortures pool. | |
275 | */ | |
276 | static void | |
277 | rcu_torture_free(struct rcu_torture *p) | |
278 | { | |
279 | atomic_inc(&n_rcu_torture_free); | |
adac1665 | 280 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 | 281 | list_add_tail(&p->rtort_free, &rcu_torture_freelist); |
adac1665 | 282 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
283 | } |
284 | ||
72e9bb54 PM |
285 | /* |
286 | * Operations vector for selecting different types of tests. | |
287 | */ | |
288 | ||
289 | struct rcu_torture_ops { | |
ad0dc7f9 | 290 | int ttype; |
72e9bb54 | 291 | void (*init)(void); |
ca1d51ed | 292 | void (*cleanup)(void); |
72e9bb54 | 293 | int (*readlock)(void); |
c116dba6 PM |
294 | void (*read_delay)(struct torture_random_state *rrsp, |
295 | struct rt_read_seg *rtrsp); | |
72e9bb54 | 296 | void (*readunlock)(int idx); |
17ef2fe9 | 297 | unsigned long (*get_gp_seq)(void); |
d7219312 | 298 | unsigned long (*gp_diff)(unsigned long new, unsigned long old); |
0acc512c | 299 | void (*deferred_free)(struct rcu_torture *p); |
b772e1dd | 300 | void (*sync)(void); |
2ec1f2d9 | 301 | void (*exp_sync)(void); |
a48f3fad PM |
302 | unsigned long (*get_state)(void); |
303 | void (*cond_sync)(unsigned long oldstate); | |
db3e8db4 | 304 | call_rcu_func_t call; |
2326974d | 305 | void (*cb_barrier)(void); |
bf66f18e | 306 | void (*fqs)(void); |
eea203fe | 307 | void (*stats)(void); |
1b27291b | 308 | int (*stall_dur)(void); |
0acc512c | 309 | int irq_capable; |
8e8be45e | 310 | int can_boost; |
2397d072 | 311 | int extendables; |
5eabea59 | 312 | int slow_gps; |
e66c33d5 | 313 | const char *name; |
72e9bb54 | 314 | }; |
a71fca58 PM |
315 | |
316 | static struct rcu_torture_ops *cur_ops; | |
72e9bb54 PM |
317 | |
318 | /* | |
319 | * Definitions for rcu torture testing. | |
320 | */ | |
321 | ||
a49a4af7 | 322 | static int rcu_torture_read_lock(void) __acquires(RCU) |
72e9bb54 PM |
323 | { |
324 | rcu_read_lock(); | |
325 | return 0; | |
326 | } | |
327 | ||
c116dba6 PM |
328 | static void |
329 | rcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp) | |
b2896d2e | 330 | { |
d0af39e8 PM |
331 | unsigned long started; |
332 | unsigned long completed; | |
b8d57a76 | 333 | const unsigned long shortdelay_us = 200; |
1e696765 | 334 | unsigned long longdelay_ms = 300; |
d0af39e8 | 335 | unsigned long long ts; |
b2896d2e | 336 | |
b8d57a76 JT |
337 | /* We want a short delay sometimes to make a reader delay the grace |
338 | * period, and we want a long delay occasionally to trigger | |
339 | * force_quiescent_state. */ | |
b2896d2e | 340 | |
48718485 PM |
341 | if (!rcu_fwd_cb_nodelay && |
342 | !(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) { | |
17ef2fe9 | 343 | started = cur_ops->get_gp_seq(); |
d0af39e8 | 344 | ts = rcu_trace_clock_local(); |
1e696765 PM |
345 | if (preempt_count() & (SOFTIRQ_MASK | HARDIRQ_MASK)) |
346 | longdelay_ms = 5; /* Avoid triggering BH limits. */ | |
b8d57a76 | 347 | mdelay(longdelay_ms); |
c116dba6 | 348 | rtrsp->rt_delay_ms = longdelay_ms; |
17ef2fe9 | 349 | completed = cur_ops->get_gp_seq(); |
d0af39e8 PM |
350 | do_trace_rcu_torture_read(cur_ops->name, NULL, ts, |
351 | started, completed); | |
352 | } | |
c116dba6 | 353 | if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) { |
b8d57a76 | 354 | udelay(shortdelay_us); |
c116dba6 PM |
355 | rtrsp->rt_delay_us = shortdelay_us; |
356 | } | |
51b1130e | 357 | if (!preempt_count() && |
c116dba6 | 358 | !(torture_random(rrsp) % (nrealreaders * 500))) { |
cc1321c9 | 359 | torture_preempt_schedule(); /* QS only if preemptible. */ |
c116dba6 PM |
360 | rtrsp->rt_preempted = true; |
361 | } | |
b2896d2e PM |
362 | } |
363 | ||
a49a4af7 | 364 | static void rcu_torture_read_unlock(int idx) __releases(RCU) |
72e9bb54 PM |
365 | { |
366 | rcu_read_unlock(); | |
367 | } | |
368 | ||
a48f3fad PM |
369 | /* |
370 | * Update callback in the pipe. This should be invoked after a grace period. | |
371 | */ | |
372 | static bool | |
373 | rcu_torture_pipe_update_one(struct rcu_torture *rp) | |
374 | { | |
375 | int i; | |
376 | ||
377 | i = rp->rtort_pipe_count; | |
378 | if (i > RCU_TORTURE_PIPE_LEN) | |
379 | i = RCU_TORTURE_PIPE_LEN; | |
380 | atomic_inc(&rcu_torture_wcount[i]); | |
381 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
382 | rp->rtort_mbtest = 0; | |
383 | return true; | |
384 | } | |
385 | return false; | |
386 | } | |
387 | ||
388 | /* | |
389 | * Update all callbacks in the pipe. Suitable for synchronous grace-period | |
390 | * primitives. | |
391 | */ | |
392 | static void | |
393 | rcu_torture_pipe_update(struct rcu_torture *old_rp) | |
394 | { | |
395 | struct rcu_torture *rp; | |
396 | struct rcu_torture *rp1; | |
397 | ||
398 | if (old_rp) | |
399 | list_add(&old_rp->rtort_free, &rcu_torture_removed); | |
400 | list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) { | |
401 | if (rcu_torture_pipe_update_one(rp)) { | |
402 | list_del(&rp->rtort_free); | |
403 | rcu_torture_free(rp); | |
404 | } | |
405 | } | |
406 | } | |
407 | ||
72e9bb54 PM |
408 | static void |
409 | rcu_torture_cb(struct rcu_head *p) | |
410 | { | |
72e9bb54 PM |
411 | struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); |
412 | ||
36970bb9 | 413 | if (torture_must_stop_irq()) { |
72e9bb54 PM |
414 | /* Test is ending, just drop callbacks on the floor. */ |
415 | /* The next initialization will pick up the pieces. */ | |
416 | return; | |
417 | } | |
a48f3fad | 418 | if (rcu_torture_pipe_update_one(rp)) |
72e9bb54 | 419 | rcu_torture_free(rp); |
a48f3fad | 420 | else |
0acc512c | 421 | cur_ops->deferred_free(rp); |
72e9bb54 PM |
422 | } |
423 | ||
6b80da42 | 424 | static unsigned long rcu_no_completed(void) |
d9a3da06 PM |
425 | { |
426 | return 0; | |
427 | } | |
428 | ||
72e9bb54 PM |
429 | static void rcu_torture_deferred_free(struct rcu_torture *p) |
430 | { | |
431 | call_rcu(&p->rtort_rcu, rcu_torture_cb); | |
432 | } | |
433 | ||
e3033736 JT |
434 | static void rcu_sync_torture_init(void) |
435 | { | |
436 | INIT_LIST_HEAD(&rcu_torture_removed); | |
437 | } | |
438 | ||
2ec1f2d9 | 439 | static struct rcu_torture_ops rcu_ops = { |
ad0dc7f9 | 440 | .ttype = RCU_FLAVOR, |
0acc512c | 441 | .init = rcu_sync_torture_init, |
0acc512c PM |
442 | .readlock = rcu_torture_read_lock, |
443 | .read_delay = rcu_read_delay, | |
444 | .readunlock = rcu_torture_read_unlock, | |
17ef2fe9 | 445 | .get_gp_seq = rcu_get_gp_seq, |
d7219312 | 446 | .gp_diff = rcu_seq_diff, |
2ec1f2d9 | 447 | .deferred_free = rcu_torture_deferred_free, |
0acc512c | 448 | .sync = synchronize_rcu, |
2ec1f2d9 | 449 | .exp_sync = synchronize_rcu_expedited, |
a48f3fad PM |
450 | .get_state = get_state_synchronize_rcu, |
451 | .cond_sync = cond_synchronize_rcu, | |
2ec1f2d9 PM |
452 | .call = call_rcu, |
453 | .cb_barrier = rcu_barrier, | |
bf66f18e | 454 | .fqs = rcu_force_quiescent_state, |
d9a3da06 | 455 | .stats = NULL, |
1b27291b | 456 | .stall_dur = rcu_jiffies_till_stall_check, |
d9a3da06 | 457 | .irq_capable = 1, |
8e8be45e | 458 | .can_boost = rcu_can_boost(), |
c0335743 | 459 | .extendables = RCUTORTURE_MAX_EXTEND, |
2ec1f2d9 | 460 | .name = "rcu" |
d9a3da06 PM |
461 | }; |
462 | ||
ff20e251 PM |
463 | /* |
464 | * Don't even think about trying any of these in real life!!! | |
465 | * The names includes "busted", and they really means it! | |
466 | * The only purpose of these functions is to provide a buggy RCU | |
467 | * implementation to make sure that rcutorture correctly emits | |
468 | * buggy-RCU error messages. | |
469 | */ | |
470 | static void rcu_busted_torture_deferred_free(struct rcu_torture *p) | |
471 | { | |
472 | /* This is a deliberate bug for testing purposes only! */ | |
473 | rcu_torture_cb(&p->rtort_rcu); | |
474 | } | |
475 | ||
476 | static void synchronize_rcu_busted(void) | |
477 | { | |
478 | /* This is a deliberate bug for testing purposes only! */ | |
479 | } | |
480 | ||
481 | static void | |
b6a4ae76 | 482 | call_rcu_busted(struct rcu_head *head, rcu_callback_t func) |
ff20e251 PM |
483 | { |
484 | /* This is a deliberate bug for testing purposes only! */ | |
485 | func(head); | |
486 | } | |
487 | ||
488 | static struct rcu_torture_ops rcu_busted_ops = { | |
ad0dc7f9 | 489 | .ttype = INVALID_RCU_FLAVOR, |
ff20e251 PM |
490 | .init = rcu_sync_torture_init, |
491 | .readlock = rcu_torture_read_lock, | |
492 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
493 | .readunlock = rcu_torture_read_unlock, | |
17ef2fe9 | 494 | .get_gp_seq = rcu_no_completed, |
ff20e251 PM |
495 | .deferred_free = rcu_busted_torture_deferred_free, |
496 | .sync = synchronize_rcu_busted, | |
497 | .exp_sync = synchronize_rcu_busted, | |
498 | .call = call_rcu_busted, | |
499 | .cb_barrier = NULL, | |
500 | .fqs = NULL, | |
501 | .stats = NULL, | |
502 | .irq_capable = 1, | |
b3c98314 | 503 | .name = "busted" |
ff20e251 PM |
504 | }; |
505 | ||
b2896d2e PM |
506 | /* |
507 | * Definitions for srcu torture testing. | |
508 | */ | |
509 | ||
cda4dc81 | 510 | DEFINE_STATIC_SRCU(srcu_ctl); |
ca1d51ed PM |
511 | static struct srcu_struct srcu_ctld; |
512 | static struct srcu_struct *srcu_ctlp = &srcu_ctl; | |
b2896d2e | 513 | |
ca1d51ed | 514 | static int srcu_torture_read_lock(void) __acquires(srcu_ctlp) |
b2896d2e | 515 | { |
ca1d51ed | 516 | return srcu_read_lock(srcu_ctlp); |
b2896d2e PM |
517 | } |
518 | ||
c116dba6 PM |
519 | static void |
520 | srcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp) | |
b2896d2e PM |
521 | { |
522 | long delay; | |
523 | const long uspertick = 1000000 / HZ; | |
524 | const long longdelay = 10; | |
525 | ||
526 | /* We want there to be long-running readers, but not all the time. */ | |
527 | ||
51b1130e PM |
528 | delay = torture_random(rrsp) % |
529 | (nrealreaders * 2 * longdelay * uspertick); | |
c116dba6 | 530 | if (!delay && in_task()) { |
b2896d2e | 531 | schedule_timeout_interruptible(longdelay); |
c116dba6 PM |
532 | rtrsp->rt_delay_jiffies = longdelay; |
533 | } else { | |
534 | rcu_read_delay(rrsp, rtrsp); | |
535 | } | |
b2896d2e PM |
536 | } |
537 | ||
ca1d51ed | 538 | static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp) |
b2896d2e | 539 | { |
ca1d51ed | 540 | srcu_read_unlock(srcu_ctlp, idx); |
b2896d2e PM |
541 | } |
542 | ||
6b80da42 | 543 | static unsigned long srcu_torture_completed(void) |
b2896d2e | 544 | { |
ca1d51ed | 545 | return srcu_batches_completed(srcu_ctlp); |
b2896d2e PM |
546 | } |
547 | ||
9059c940 LJ |
548 | static void srcu_torture_deferred_free(struct rcu_torture *rp) |
549 | { | |
ca1d51ed | 550 | call_srcu(srcu_ctlp, &rp->rtort_rcu, rcu_torture_cb); |
9059c940 LJ |
551 | } |
552 | ||
b772e1dd JT |
553 | static void srcu_torture_synchronize(void) |
554 | { | |
ca1d51ed | 555 | synchronize_srcu(srcu_ctlp); |
b772e1dd JT |
556 | } |
557 | ||
e3f8d378 | 558 | static void srcu_torture_call(struct rcu_head *head, |
b6a4ae76 | 559 | rcu_callback_t func) |
e3f8d378 | 560 | { |
ca1d51ed | 561 | call_srcu(srcu_ctlp, head, func); |
e3f8d378 PM |
562 | } |
563 | ||
564 | static void srcu_torture_barrier(void) | |
565 | { | |
ca1d51ed | 566 | srcu_barrier(srcu_ctlp); |
e3f8d378 PM |
567 | } |
568 | ||
eea203fe | 569 | static void srcu_torture_stats(void) |
b2896d2e | 570 | { |
115a1a52 | 571 | srcu_torture_stats_print(srcu_ctlp, torture_type, TORTURE_FLAG); |
b2896d2e PM |
572 | } |
573 | ||
2ec1f2d9 PM |
574 | static void srcu_torture_synchronize_expedited(void) |
575 | { | |
ca1d51ed | 576 | synchronize_srcu_expedited(srcu_ctlp); |
2ec1f2d9 PM |
577 | } |
578 | ||
b2896d2e | 579 | static struct rcu_torture_ops srcu_ops = { |
ad0dc7f9 | 580 | .ttype = SRCU_FLAVOR, |
cda4dc81 | 581 | .init = rcu_sync_torture_init, |
0acc512c PM |
582 | .readlock = srcu_torture_read_lock, |
583 | .read_delay = srcu_read_delay, | |
584 | .readunlock = srcu_torture_read_unlock, | |
17ef2fe9 | 585 | .get_gp_seq = srcu_torture_completed, |
9059c940 | 586 | .deferred_free = srcu_torture_deferred_free, |
0acc512c | 587 | .sync = srcu_torture_synchronize, |
2ec1f2d9 | 588 | .exp_sync = srcu_torture_synchronize_expedited, |
e3f8d378 PM |
589 | .call = srcu_torture_call, |
590 | .cb_barrier = srcu_torture_barrier, | |
0acc512c | 591 | .stats = srcu_torture_stats, |
5e741fa9 | 592 | .irq_capable = 1, |
0acc512c | 593 | .name = "srcu" |
b2896d2e PM |
594 | }; |
595 | ||
ca1d51ed PM |
596 | static void srcu_torture_init(void) |
597 | { | |
598 | rcu_sync_torture_init(); | |
599 | WARN_ON(init_srcu_struct(&srcu_ctld)); | |
600 | srcu_ctlp = &srcu_ctld; | |
601 | } | |
602 | ||
603 | static void srcu_torture_cleanup(void) | |
604 | { | |
f5ad3991 | 605 | cleanup_srcu_struct(&srcu_ctld); |
ca1d51ed PM |
606 | srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */ |
607 | } | |
608 | ||
609 | /* As above, but dynamically allocated. */ | |
610 | static struct rcu_torture_ops srcud_ops = { | |
611 | .ttype = SRCU_FLAVOR, | |
612 | .init = srcu_torture_init, | |
613 | .cleanup = srcu_torture_cleanup, | |
614 | .readlock = srcu_torture_read_lock, | |
615 | .read_delay = srcu_read_delay, | |
616 | .readunlock = srcu_torture_read_unlock, | |
17ef2fe9 | 617 | .get_gp_seq = srcu_torture_completed, |
ca1d51ed PM |
618 | .deferred_free = srcu_torture_deferred_free, |
619 | .sync = srcu_torture_synchronize, | |
620 | .exp_sync = srcu_torture_synchronize_expedited, | |
621 | .call = srcu_torture_call, | |
622 | .cb_barrier = srcu_torture_barrier, | |
623 | .stats = srcu_torture_stats, | |
5e741fa9 | 624 | .irq_capable = 1, |
ca1d51ed PM |
625 | .name = "srcud" |
626 | }; | |
627 | ||
2397d072 PM |
628 | /* As above, but broken due to inappropriate reader extension. */ |
629 | static struct rcu_torture_ops busted_srcud_ops = { | |
630 | .ttype = SRCU_FLAVOR, | |
631 | .init = srcu_torture_init, | |
632 | .cleanup = srcu_torture_cleanup, | |
633 | .readlock = srcu_torture_read_lock, | |
634 | .read_delay = rcu_read_delay, | |
635 | .readunlock = srcu_torture_read_unlock, | |
636 | .get_gp_seq = srcu_torture_completed, | |
637 | .deferred_free = srcu_torture_deferred_free, | |
638 | .sync = srcu_torture_synchronize, | |
639 | .exp_sync = srcu_torture_synchronize_expedited, | |
640 | .call = srcu_torture_call, | |
641 | .cb_barrier = srcu_torture_barrier, | |
642 | .stats = srcu_torture_stats, | |
643 | .irq_capable = 1, | |
644 | .extendables = RCUTORTURE_MAX_EXTEND, | |
645 | .name = "busted_srcud" | |
646 | }; | |
647 | ||
69c60455 PM |
648 | /* |
649 | * Definitions for RCU-tasks torture testing. | |
650 | */ | |
651 | ||
652 | static int tasks_torture_read_lock(void) | |
653 | { | |
654 | return 0; | |
655 | } | |
656 | ||
657 | static void tasks_torture_read_unlock(int idx) | |
658 | { | |
659 | } | |
660 | ||
661 | static void rcu_tasks_torture_deferred_free(struct rcu_torture *p) | |
662 | { | |
663 | call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb); | |
664 | } | |
665 | ||
666 | static struct rcu_torture_ops tasks_ops = { | |
667 | .ttype = RCU_TASKS_FLAVOR, | |
668 | .init = rcu_sync_torture_init, | |
669 | .readlock = tasks_torture_read_lock, | |
670 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
671 | .readunlock = tasks_torture_read_unlock, | |
17ef2fe9 | 672 | .get_gp_seq = rcu_no_completed, |
69c60455 PM |
673 | .deferred_free = rcu_tasks_torture_deferred_free, |
674 | .sync = synchronize_rcu_tasks, | |
675 | .exp_sync = synchronize_rcu_tasks, | |
676 | .call = call_rcu_tasks, | |
677 | .cb_barrier = rcu_barrier_tasks, | |
678 | .fqs = NULL, | |
679 | .stats = NULL, | |
680 | .irq_capable = 1, | |
5eabea59 | 681 | .slow_gps = 1, |
69c60455 PM |
682 | .name = "tasks" |
683 | }; | |
684 | ||
c682db55 PM |
685 | /* |
686 | * Definitions for trivial CONFIG_PREEMPT=n-only torture testing. | |
687 | * This implementation does not necessarily work well with CPU hotplug. | |
688 | */ | |
689 | ||
690 | static void synchronize_rcu_trivial(void) | |
691 | { | |
692 | int cpu; | |
693 | ||
694 | for_each_online_cpu(cpu) { | |
695 | rcutorture_sched_setaffinity(current->pid, cpumask_of(cpu)); | |
696 | WARN_ON_ONCE(raw_smp_processor_id() != cpu); | |
697 | } | |
698 | } | |
699 | ||
700 | static int rcu_torture_read_lock_trivial(void) __acquires(RCU) | |
701 | { | |
702 | preempt_disable(); | |
703 | return 0; | |
704 | } | |
705 | ||
706 | static void rcu_torture_read_unlock_trivial(int idx) __releases(RCU) | |
707 | { | |
708 | preempt_enable(); | |
709 | } | |
710 | ||
711 | static struct rcu_torture_ops trivial_ops = { | |
712 | .ttype = RCU_TRIVIAL_FLAVOR, | |
713 | .init = rcu_sync_torture_init, | |
714 | .readlock = rcu_torture_read_lock_trivial, | |
715 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
716 | .readunlock = rcu_torture_read_unlock_trivial, | |
717 | .get_gp_seq = rcu_no_completed, | |
718 | .sync = synchronize_rcu_trivial, | |
719 | .exp_sync = synchronize_rcu_trivial, | |
720 | .fqs = NULL, | |
721 | .stats = NULL, | |
722 | .irq_capable = 1, | |
723 | .name = "trivial" | |
724 | }; | |
725 | ||
d7219312 PM |
726 | static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old) |
727 | { | |
728 | if (!cur_ops->gp_diff) | |
729 | return new - old; | |
730 | return cur_ops->gp_diff(new, old); | |
731 | } | |
732 | ||
5be5d1a1 PM |
733 | static bool __maybe_unused torturing_tasks(void) |
734 | { | |
735 | return cur_ops == &tasks_ops; | |
736 | } | |
737 | ||
8e8be45e PM |
738 | /* |
739 | * RCU torture priority-boost testing. Runs one real-time thread per | |
740 | * CPU for moderate bursts, repeatedly registering RCU callbacks and | |
741 | * spinning waiting for them to be invoked. If a given callback takes | |
742 | * too long to be invoked, we assume that priority inversion has occurred. | |
743 | */ | |
744 | ||
745 | struct rcu_boost_inflight { | |
746 | struct rcu_head rcu; | |
747 | int inflight; | |
748 | }; | |
749 | ||
750 | static void rcu_torture_boost_cb(struct rcu_head *head) | |
751 | { | |
752 | struct rcu_boost_inflight *rbip = | |
753 | container_of(head, struct rcu_boost_inflight, rcu); | |
754 | ||
6c7ed42c PM |
755 | /* Ensure RCU-core accesses precede clearing ->inflight */ |
756 | smp_store_release(&rbip->inflight, 0); | |
8e8be45e PM |
757 | } |
758 | ||
450efca7 JFG |
759 | static int old_rt_runtime = -1; |
760 | ||
761 | static void rcu_torture_disable_rt_throttle(void) | |
762 | { | |
763 | /* | |
764 | * Disable RT throttling so that rcutorture's boost threads don't get | |
765 | * throttled. Only possible if rcutorture is built-in otherwise the | |
766 | * user should manually do this by setting the sched_rt_period_us and | |
767 | * sched_rt_runtime sysctls. | |
768 | */ | |
769 | if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime != -1) | |
770 | return; | |
771 | ||
772 | old_rt_runtime = sysctl_sched_rt_runtime; | |
773 | sysctl_sched_rt_runtime = -1; | |
774 | } | |
775 | ||
776 | static void rcu_torture_enable_rt_throttle(void) | |
777 | { | |
778 | if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime == -1) | |
779 | return; | |
780 | ||
781 | sysctl_sched_rt_runtime = old_rt_runtime; | |
782 | old_rt_runtime = -1; | |
783 | } | |
784 | ||
3b745c89 JFG |
785 | static bool rcu_torture_boost_failed(unsigned long start, unsigned long end) |
786 | { | |
787 | if (end - start > test_boost_duration * HZ - HZ / 2) { | |
788 | VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed"); | |
789 | n_rcu_torture_boost_failure++; | |
790 | ||
791 | return true; /* failed */ | |
792 | } | |
793 | ||
794 | return false; /* passed */ | |
795 | } | |
796 | ||
8e8be45e PM |
797 | static int rcu_torture_boost(void *arg) |
798 | { | |
799 | unsigned long call_rcu_time; | |
800 | unsigned long endtime; | |
801 | unsigned long oldstarttime; | |
802 | struct rcu_boost_inflight rbi = { .inflight = 0 }; | |
803 | struct sched_param sp; | |
804 | ||
5ccf60f2 | 805 | VERBOSE_TOROUT_STRING("rcu_torture_boost started"); |
8e8be45e PM |
806 | |
807 | /* Set real-time priority. */ | |
808 | sp.sched_priority = 1; | |
809 | if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) { | |
5ccf60f2 | 810 | VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!"); |
8e8be45e PM |
811 | n_rcu_torture_boost_rterror++; |
812 | } | |
813 | ||
561190e3 | 814 | init_rcu_head_on_stack(&rbi.rcu); |
8e8be45e PM |
815 | /* Each pass through the following loop does one boost-test cycle. */ |
816 | do { | |
3b745c89 JFG |
817 | /* Track if the test failed already in this test interval? */ |
818 | bool failed = false; | |
819 | ||
820 | /* Increment n_rcu_torture_boosts once per boost-test */ | |
821 | while (!kthread_should_stop()) { | |
822 | if (mutex_trylock(&boost_mutex)) { | |
823 | n_rcu_torture_boosts++; | |
824 | mutex_unlock(&boost_mutex); | |
825 | break; | |
826 | } | |
827 | schedule_timeout_uninterruptible(1); | |
828 | } | |
829 | if (kthread_should_stop()) | |
830 | goto checkwait; | |
831 | ||
8e8be45e PM |
832 | /* Wait for the next test interval. */ |
833 | oldstarttime = boost_starttime; | |
93898fb1 | 834 | while (ULONG_CMP_LT(jiffies, oldstarttime)) { |
0e11c8e8 | 835 | schedule_timeout_interruptible(oldstarttime - jiffies); |
628edaa5 | 836 | stutter_wait("rcu_torture_boost"); |
36970bb9 | 837 | if (torture_must_stop()) |
8e8be45e PM |
838 | goto checkwait; |
839 | } | |
840 | ||
841 | /* Do one boost-test interval. */ | |
842 | endtime = oldstarttime + test_boost_duration * HZ; | |
843 | call_rcu_time = jiffies; | |
93898fb1 | 844 | while (ULONG_CMP_LT(jiffies, endtime)) { |
8e8be45e | 845 | /* If we don't have a callback in flight, post one. */ |
6c7ed42c PM |
846 | if (!smp_load_acquire(&rbi.inflight)) { |
847 | /* RCU core before ->inflight = 1. */ | |
848 | smp_store_release(&rbi.inflight, 1); | |
8e8be45e | 849 | call_rcu(&rbi.rcu, rcu_torture_boost_cb); |
3b745c89 JFG |
850 | /* Check if the boost test failed */ |
851 | failed = failed || | |
852 | rcu_torture_boost_failed(call_rcu_time, | |
853 | jiffies); | |
8e8be45e PM |
854 | call_rcu_time = jiffies; |
855 | } | |
628edaa5 | 856 | stutter_wait("rcu_torture_boost"); |
36970bb9 | 857 | if (torture_must_stop()) |
8e8be45e PM |
858 | goto checkwait; |
859 | } | |
860 | ||
3b745c89 JFG |
861 | /* |
862 | * If boost never happened, then inflight will always be 1, in | |
863 | * this case the boost check would never happen in the above | |
864 | * loop so do another one here. | |
865 | */ | |
866 | if (!failed && smp_load_acquire(&rbi.inflight)) | |
867 | rcu_torture_boost_failed(call_rcu_time, jiffies); | |
868 | ||
8e8be45e PM |
869 | /* |
870 | * Set the start time of the next test interval. | |
871 | * Yes, this is vulnerable to long delays, but such | |
872 | * delays simply cause a false negative for the next | |
873 | * interval. Besides, we are running at RT priority, | |
874 | * so delays should be relatively rare. | |
875 | */ | |
ab8f11e5 PM |
876 | while (oldstarttime == boost_starttime && |
877 | !kthread_should_stop()) { | |
8e8be45e PM |
878 | if (mutex_trylock(&boost_mutex)) { |
879 | boost_starttime = jiffies + | |
880 | test_boost_interval * HZ; | |
8e8be45e PM |
881 | mutex_unlock(&boost_mutex); |
882 | break; | |
883 | } | |
884 | schedule_timeout_uninterruptible(1); | |
885 | } | |
886 | ||
887 | /* Go do the stutter. */ | |
628edaa5 | 888 | checkwait: stutter_wait("rcu_torture_boost"); |
36970bb9 | 889 | } while (!torture_must_stop()); |
8e8be45e PM |
890 | |
891 | /* Clean up and exit. */ | |
6c7ed42c | 892 | while (!kthread_should_stop() || smp_load_acquire(&rbi.inflight)) { |
7fafaac5 | 893 | torture_shutdown_absorb("rcu_torture_boost"); |
8e8be45e | 894 | schedule_timeout_uninterruptible(1); |
7fafaac5 | 895 | } |
9d68197c | 896 | destroy_rcu_head_on_stack(&rbi.rcu); |
7fafaac5 | 897 | torture_kthread_stopping("rcu_torture_boost"); |
8e8be45e PM |
898 | return 0; |
899 | } | |
900 | ||
bf66f18e PM |
901 | /* |
902 | * RCU torture force-quiescent-state kthread. Repeatedly induces | |
903 | * bursts of calls to force_quiescent_state(), increasing the probability | |
904 | * of occurrence of some important types of race conditions. | |
905 | */ | |
906 | static int | |
907 | rcu_torture_fqs(void *arg) | |
908 | { | |
909 | unsigned long fqs_resume_time; | |
910 | int fqs_burst_remaining; | |
911 | ||
5ccf60f2 | 912 | VERBOSE_TOROUT_STRING("rcu_torture_fqs task started"); |
bf66f18e PM |
913 | do { |
914 | fqs_resume_time = jiffies + fqs_stutter * HZ; | |
93898fb1 PM |
915 | while (ULONG_CMP_LT(jiffies, fqs_resume_time) && |
916 | !kthread_should_stop()) { | |
bf66f18e PM |
917 | schedule_timeout_interruptible(1); |
918 | } | |
919 | fqs_burst_remaining = fqs_duration; | |
93898fb1 PM |
920 | while (fqs_burst_remaining > 0 && |
921 | !kthread_should_stop()) { | |
bf66f18e PM |
922 | cur_ops->fqs(); |
923 | udelay(fqs_holdoff); | |
924 | fqs_burst_remaining -= fqs_holdoff; | |
925 | } | |
628edaa5 | 926 | stutter_wait("rcu_torture_fqs"); |
36970bb9 | 927 | } while (!torture_must_stop()); |
7fafaac5 | 928 | torture_kthread_stopping("rcu_torture_fqs"); |
bf66f18e PM |
929 | return 0; |
930 | } | |
931 | ||
a241ec65 PM |
932 | /* |
933 | * RCU torture writer kthread. Repeatedly substitutes a new structure | |
934 | * for that pointed to by rcu_torture_current, freeing the old structure | |
935 | * after a series of grace periods (the "pipeline"). | |
936 | */ | |
937 | static int | |
938 | rcu_torture_writer(void *arg) | |
939 | { | |
9efafb88 | 940 | bool can_expedite = !rcu_gp_is_expedited() && !rcu_gp_is_normal(); |
4bb3c5f4 | 941 | int expediting = 0; |
a48f3fad PM |
942 | unsigned long gp_snap; |
943 | bool gp_cond1 = gp_cond, gp_exp1 = gp_exp, gp_normal1 = gp_normal; | |
f0bf8fab | 944 | bool gp_sync1 = gp_sync; |
a241ec65 | 945 | int i; |
a241ec65 PM |
946 | struct rcu_torture *rp; |
947 | struct rcu_torture *old_rp; | |
51b1130e | 948 | static DEFINE_TORTURE_RANDOM(rand); |
f0bf8fab PM |
949 | int synctype[] = { RTWS_DEF_FREE, RTWS_EXP_SYNC, |
950 | RTWS_COND_GET, RTWS_SYNC }; | |
a48f3fad | 951 | int nsynctypes = 0; |
a241ec65 | 952 | |
5ccf60f2 | 953 | VERBOSE_TOROUT_STRING("rcu_torture_writer task started"); |
f7c0e6ad | 954 | if (!can_expedite) |
aa5a8988 | 955 | pr_alert("%s" TORTURE_FLAG |
f7c0e6ad | 956 | " GP expediting controlled from boot/sysfs for %s.\n", |
aa5a8988 | 957 | torture_type, cur_ops->name); |
dbdf65b1 | 958 | |
a48f3fad | 959 | /* Initialize synctype[] array. If none set, take default. */ |
c136f991 | 960 | if (!gp_cond1 && !gp_exp1 && !gp_normal1 && !gp_sync1) |
f0bf8fab | 961 | gp_cond1 = gp_exp1 = gp_normal1 = gp_sync1 = true; |
db0c1a8a | 962 | if (gp_cond1 && cur_ops->get_state && cur_ops->cond_sync) { |
a48f3fad | 963 | synctype[nsynctypes++] = RTWS_COND_GET; |
db0c1a8a PM |
964 | pr_info("%s: Testing conditional GPs.\n", __func__); |
965 | } else if (gp_cond && (!cur_ops->get_state || !cur_ops->cond_sync)) { | |
e0d31a34 | 966 | pr_alert("%s: gp_cond without primitives.\n", __func__); |
db0c1a8a PM |
967 | } |
968 | if (gp_exp1 && cur_ops->exp_sync) { | |
a48f3fad | 969 | synctype[nsynctypes++] = RTWS_EXP_SYNC; |
db0c1a8a PM |
970 | pr_info("%s: Testing expedited GPs.\n", __func__); |
971 | } else if (gp_exp && !cur_ops->exp_sync) { | |
e0d31a34 | 972 | pr_alert("%s: gp_exp without primitives.\n", __func__); |
db0c1a8a PM |
973 | } |
974 | if (gp_normal1 && cur_ops->deferred_free) { | |
a48f3fad | 975 | synctype[nsynctypes++] = RTWS_DEF_FREE; |
db0c1a8a PM |
976 | pr_info("%s: Testing asynchronous GPs.\n", __func__); |
977 | } else if (gp_normal && !cur_ops->deferred_free) { | |
e0d31a34 | 978 | pr_alert("%s: gp_normal without primitives.\n", __func__); |
db0c1a8a PM |
979 | } |
980 | if (gp_sync1 && cur_ops->sync) { | |
f0bf8fab | 981 | synctype[nsynctypes++] = RTWS_SYNC; |
db0c1a8a PM |
982 | pr_info("%s: Testing normal GPs.\n", __func__); |
983 | } else if (gp_sync && !cur_ops->sync) { | |
e0d31a34 | 984 | pr_alert("%s: gp_sync without primitives.\n", __func__); |
db0c1a8a | 985 | } |
a48f3fad PM |
986 | if (WARN_ONCE(nsynctypes == 0, |
987 | "rcu_torture_writer: No update-side primitives.\n")) { | |
f0bf8fab PM |
988 | /* |
989 | * No updates primitives, so don't try updating. | |
990 | * The resulting test won't be testing much, hence the | |
991 | * above WARN_ONCE(). | |
992 | */ | |
a48f3fad PM |
993 | rcu_torture_writer_state = RTWS_STOPPING; |
994 | torture_kthread_stopping("rcu_torture_writer"); | |
995 | } | |
996 | ||
a241ec65 | 997 | do { |
ad0dc7f9 | 998 | rcu_torture_writer_state = RTWS_FIXED_DELAY; |
a241ec65 | 999 | schedule_timeout_uninterruptible(1); |
a71fca58 PM |
1000 | rp = rcu_torture_alloc(); |
1001 | if (rp == NULL) | |
a241ec65 PM |
1002 | continue; |
1003 | rp->rtort_pipe_count = 0; | |
ad0dc7f9 | 1004 | rcu_torture_writer_state = RTWS_DELAY; |
51b1130e | 1005 | udelay(torture_random(&rand) & 0x3ff); |
ad0dc7f9 | 1006 | rcu_torture_writer_state = RTWS_REPLACE; |
0ddea0ea PM |
1007 | old_rp = rcu_dereference_check(rcu_torture_current, |
1008 | current == writer_task); | |
996417d2 | 1009 | rp->rtort_mbtest = 1; |
a241ec65 | 1010 | rcu_assign_pointer(rcu_torture_current, rp); |
9b2619af | 1011 | smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */ |
c8e5b163 | 1012 | if (old_rp) { |
a241ec65 PM |
1013 | i = old_rp->rtort_pipe_count; |
1014 | if (i > RCU_TORTURE_PIPE_LEN) | |
1015 | i = RCU_TORTURE_PIPE_LEN; | |
1016 | atomic_inc(&rcu_torture_wcount[i]); | |
1017 | old_rp->rtort_pipe_count++; | |
a48f3fad PM |
1018 | switch (synctype[torture_random(&rand) % nsynctypes]) { |
1019 | case RTWS_DEF_FREE: | |
ad0dc7f9 | 1020 | rcu_torture_writer_state = RTWS_DEF_FREE; |
2ec1f2d9 | 1021 | cur_ops->deferred_free(old_rp); |
a48f3fad PM |
1022 | break; |
1023 | case RTWS_EXP_SYNC: | |
ad0dc7f9 | 1024 | rcu_torture_writer_state = RTWS_EXP_SYNC; |
2ec1f2d9 | 1025 | cur_ops->exp_sync(); |
a48f3fad PM |
1026 | rcu_torture_pipe_update(old_rp); |
1027 | break; | |
1028 | case RTWS_COND_GET: | |
1029 | rcu_torture_writer_state = RTWS_COND_GET; | |
1030 | gp_snap = cur_ops->get_state(); | |
1031 | i = torture_random(&rand) % 16; | |
1032 | if (i != 0) | |
1033 | schedule_timeout_interruptible(i); | |
1034 | udelay(torture_random(&rand) % 1000); | |
1035 | rcu_torture_writer_state = RTWS_COND_SYNC; | |
1036 | cur_ops->cond_sync(gp_snap); | |
1037 | rcu_torture_pipe_update(old_rp); | |
1038 | break; | |
f0bf8fab PM |
1039 | case RTWS_SYNC: |
1040 | rcu_torture_writer_state = RTWS_SYNC; | |
1041 | cur_ops->sync(); | |
1042 | rcu_torture_pipe_update(old_rp); | |
1043 | break; | |
a48f3fad PM |
1044 | default: |
1045 | WARN_ON_ONCE(1); | |
1046 | break; | |
2ec1f2d9 | 1047 | } |
a241ec65 | 1048 | } |
1b27291b PM |
1049 | WRITE_ONCE(rcu_torture_current_version, |
1050 | rcu_torture_current_version + 1); | |
4bb3c5f4 PM |
1051 | /* Cycle through nesting levels of rcu_expedite_gp() calls. */ |
1052 | if (can_expedite && | |
1053 | !(torture_random(&rand) & 0xff & (!!expediting - 1))) { | |
1054 | WARN_ON_ONCE(expediting == 0 && rcu_gp_is_expedited()); | |
1055 | if (expediting >= 0) | |
1056 | rcu_expedite_gp(); | |
1057 | else | |
1058 | rcu_unexpedite_gp(); | |
1059 | if (++expediting > 3) | |
1060 | expediting = -expediting; | |
f7c0e6ad PM |
1061 | } else if (!can_expedite) { /* Disabled during boot, recheck. */ |
1062 | can_expedite = !rcu_gp_is_expedited() && | |
1063 | !rcu_gp_is_normal(); | |
4bb3c5f4 | 1064 | } |
ad0dc7f9 | 1065 | rcu_torture_writer_state = RTWS_STUTTER; |
e8516c64 | 1066 | if (stutter_wait("rcu_torture_writer") && |
5eabea59 | 1067 | !READ_ONCE(rcu_fwd_cb_nodelay) && |
3432d765 PM |
1068 | !cur_ops->slow_gps && |
1069 | !torture_must_stop()) | |
474e59b4 | 1070 | for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) |
e8516c64 PM |
1071 | if (list_empty(&rcu_tortures[i].rtort_free) && |
1072 | rcu_access_pointer(rcu_torture_current) != | |
34aa34b8 PM |
1073 | &rcu_tortures[i]) { |
1074 | rcu_ftrace_dump(DUMP_ALL); | |
e8516c64 | 1075 | WARN(1, "%s: rtort_pipe_count: %d\n", __func__, rcu_tortures[i].rtort_pipe_count); |
34aa34b8 | 1076 | } |
36970bb9 | 1077 | } while (!torture_must_stop()); |
4bb3c5f4 PM |
1078 | /* Reset expediting back to unexpedited. */ |
1079 | if (expediting > 0) | |
1080 | expediting = -expediting; | |
1081 | while (can_expedite && expediting++ < 0) | |
1082 | rcu_unexpedite_gp(); | |
1083 | WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited()); | |
f7c0e6ad PM |
1084 | if (!can_expedite) |
1085 | pr_alert("%s" TORTURE_FLAG | |
1086 | " Dynamic grace-period expediting was disabled.\n", | |
1087 | torture_type); | |
ad0dc7f9 | 1088 | rcu_torture_writer_state = RTWS_STOPPING; |
7fafaac5 | 1089 | torture_kthread_stopping("rcu_torture_writer"); |
a241ec65 PM |
1090 | return 0; |
1091 | } | |
1092 | ||
b772e1dd JT |
1093 | /* |
1094 | * RCU torture fake writer kthread. Repeatedly calls sync, with a random | |
1095 | * delay between calls. | |
1096 | */ | |
1097 | static int | |
1098 | rcu_torture_fakewriter(void *arg) | |
1099 | { | |
51b1130e | 1100 | DEFINE_TORTURE_RANDOM(rand); |
b772e1dd | 1101 | |
5ccf60f2 | 1102 | VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started"); |
d277d868 | 1103 | set_user_nice(current, MAX_NICE); |
b772e1dd JT |
1104 | |
1105 | do { | |
51b1130e PM |
1106 | schedule_timeout_uninterruptible(1 + torture_random(&rand)%10); |
1107 | udelay(torture_random(&rand) & 0x3ff); | |
72472a02 | 1108 | if (cur_ops->cb_barrier != NULL && |
51b1130e | 1109 | torture_random(&rand) % (nfakewriters * 8) == 0) { |
72472a02 | 1110 | cur_ops->cb_barrier(); |
2ec1f2d9 | 1111 | } else if (gp_normal == gp_exp) { |
eb033993 | 1112 | if (cur_ops->sync && torture_random(&rand) & 0x80) |
2ec1f2d9 | 1113 | cur_ops->sync(); |
eb033993 | 1114 | else if (cur_ops->exp_sync) |
2ec1f2d9 | 1115 | cur_ops->exp_sync(); |
eb033993 | 1116 | } else if (gp_normal && cur_ops->sync) { |
72472a02 | 1117 | cur_ops->sync(); |
eb033993 | 1118 | } else if (cur_ops->exp_sync) { |
2ec1f2d9 PM |
1119 | cur_ops->exp_sync(); |
1120 | } | |
628edaa5 | 1121 | stutter_wait("rcu_torture_fakewriter"); |
36970bb9 | 1122 | } while (!torture_must_stop()); |
b772e1dd | 1123 | |
7fafaac5 | 1124 | torture_kthread_stopping("rcu_torture_fakewriter"); |
b772e1dd JT |
1125 | return 0; |
1126 | } | |
1127 | ||
f34c8585 PM |
1128 | static void rcu_torture_timer_cb(struct rcu_head *rhp) |
1129 | { | |
1130 | kfree(rhp); | |
1131 | } | |
1132 | ||
0729fbf3 | 1133 | /* |
2397d072 PM |
1134 | * Do one extension of an RCU read-side critical section using the |
1135 | * current reader state in readstate (set to zero for initial entry | |
1136 | * to extended critical section), set the new state as specified by | |
1137 | * newstate (set to zero for final exit from extended critical section), | |
1138 | * and random-number-generator state in trsp. If this is neither the | |
1139 | * beginning or end of the critical section and if there was actually a | |
1140 | * change, do a ->read_delay(). | |
0729fbf3 | 1141 | */ |
2397d072 | 1142 | static void rcutorture_one_extend(int *readstate, int newstate, |
c116dba6 PM |
1143 | struct torture_random_state *trsp, |
1144 | struct rt_read_seg *rtrsp) | |
2397d072 PM |
1145 | { |
1146 | int idxnew = -1; | |
1147 | int idxold = *readstate; | |
1148 | int statesnew = ~*readstate & newstate; | |
1149 | int statesold = *readstate & ~newstate; | |
1150 | ||
1151 | WARN_ON_ONCE(idxold < 0); | |
1152 | WARN_ON_ONCE((idxold >> RCUTORTURE_RDR_SHIFT) > 1); | |
c116dba6 | 1153 | rtrsp->rt_readstate = newstate; |
2397d072 PM |
1154 | |
1155 | /* First, put new protection in place to avoid critical-section gap. */ | |
1156 | if (statesnew & RCUTORTURE_RDR_BH) | |
1157 | local_bh_disable(); | |
1158 | if (statesnew & RCUTORTURE_RDR_IRQ) | |
1159 | local_irq_disable(); | |
1160 | if (statesnew & RCUTORTURE_RDR_PREEMPT) | |
1161 | preempt_disable(); | |
2ceebc03 PM |
1162 | if (statesnew & RCUTORTURE_RDR_RBH) |
1163 | rcu_read_lock_bh(); | |
1164 | if (statesnew & RCUTORTURE_RDR_SCHED) | |
1165 | rcu_read_lock_sched(); | |
2397d072 PM |
1166 | if (statesnew & RCUTORTURE_RDR_RCU) |
1167 | idxnew = cur_ops->readlock() << RCUTORTURE_RDR_SHIFT; | |
1168 | ||
1169 | /* Next, remove old protection, irq first due to bh conflict. */ | |
1170 | if (statesold & RCUTORTURE_RDR_IRQ) | |
1171 | local_irq_enable(); | |
1172 | if (statesold & RCUTORTURE_RDR_BH) | |
1173 | local_bh_enable(); | |
1174 | if (statesold & RCUTORTURE_RDR_PREEMPT) | |
1175 | preempt_enable(); | |
2ceebc03 PM |
1176 | if (statesold & RCUTORTURE_RDR_RBH) |
1177 | rcu_read_unlock_bh(); | |
1178 | if (statesold & RCUTORTURE_RDR_SCHED) | |
1179 | rcu_read_unlock_sched(); | |
2397d072 PM |
1180 | if (statesold & RCUTORTURE_RDR_RCU) |
1181 | cur_ops->readunlock(idxold >> RCUTORTURE_RDR_SHIFT); | |
1182 | ||
1183 | /* Delay if neither beginning nor end and there was a change. */ | |
1184 | if ((statesnew || statesold) && *readstate && newstate) | |
c116dba6 | 1185 | cur_ops->read_delay(trsp, rtrsp); |
2397d072 PM |
1186 | |
1187 | /* Update the reader state. */ | |
1188 | if (idxnew == -1) | |
1189 | idxnew = idxold & ~RCUTORTURE_RDR_MASK; | |
1190 | WARN_ON_ONCE(idxnew < 0); | |
1191 | WARN_ON_ONCE((idxnew >> RCUTORTURE_RDR_SHIFT) > 1); | |
1192 | *readstate = idxnew | newstate; | |
1193 | WARN_ON_ONCE((*readstate >> RCUTORTURE_RDR_SHIFT) < 0); | |
1194 | WARN_ON_ONCE((*readstate >> RCUTORTURE_RDR_SHIFT) > 1); | |
1195 | } | |
1196 | ||
1197 | /* Return the biggest extendables mask given current RCU and boot parameters. */ | |
1198 | static int rcutorture_extend_mask_max(void) | |
1199 | { | |
1200 | int mask; | |
1201 | ||
1202 | WARN_ON_ONCE(extendables & ~RCUTORTURE_MAX_EXTEND); | |
1203 | mask = extendables & RCUTORTURE_MAX_EXTEND & cur_ops->extendables; | |
1204 | mask = mask | RCUTORTURE_RDR_RCU; | |
1205 | return mask; | |
1206 | } | |
1207 | ||
1208 | /* Return a random protection state mask, but with at least one bit set. */ | |
1209 | static int | |
1210 | rcutorture_extend_mask(int oldmask, struct torture_random_state *trsp) | |
1211 | { | |
1212 | int mask = rcutorture_extend_mask_max(); | |
bf1bef50 | 1213 | unsigned long randmask1 = torture_random(trsp) >> 8; |
c116dba6 | 1214 | unsigned long randmask2 = randmask1 >> 3; |
2397d072 PM |
1215 | |
1216 | WARN_ON_ONCE(mask >> RCUTORTURE_RDR_SHIFT); | |
a3b0e1e5 | 1217 | /* Mostly only one bit (need preemption!), sometimes lots of bits. */ |
c116dba6 | 1218 | if (!(randmask1 & 0x7)) |
bf1bef50 PM |
1219 | mask = mask & randmask2; |
1220 | else | |
1221 | mask = mask & (1 << (randmask2 % RCUTORTURE_RDR_NBITS)); | |
2ceebc03 | 1222 | /* Can't enable bh w/irq disabled. */ |
2397d072 | 1223 | if ((mask & RCUTORTURE_RDR_IRQ) && |
2ceebc03 PM |
1224 | ((!(mask & RCUTORTURE_RDR_BH) && (oldmask & RCUTORTURE_RDR_BH)) || |
1225 | (!(mask & RCUTORTURE_RDR_RBH) && (oldmask & RCUTORTURE_RDR_RBH)))) | |
1226 | mask |= RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH; | |
2397d072 PM |
1227 | return mask ?: RCUTORTURE_RDR_RCU; |
1228 | } | |
1229 | ||
1230 | /* | |
1231 | * Do a randomly selected number of extensions of an existing RCU read-side | |
1232 | * critical section. | |
1233 | */ | |
c116dba6 PM |
1234 | static struct rt_read_seg * |
1235 | rcutorture_loop_extend(int *readstate, struct torture_random_state *trsp, | |
1236 | struct rt_read_seg *rtrsp) | |
2397d072 PM |
1237 | { |
1238 | int i; | |
c116dba6 | 1239 | int j; |
2397d072 PM |
1240 | int mask = rcutorture_extend_mask_max(); |
1241 | ||
1242 | WARN_ON_ONCE(!*readstate); /* -Existing- RCU read-side critsect! */ | |
1243 | if (!((mask - 1) & mask)) | |
c116dba6 PM |
1244 | return rtrsp; /* Current RCU reader not extendable. */ |
1245 | /* Bias towards larger numbers of loops. */ | |
1246 | i = (torture_random(trsp) >> 3); | |
1247 | i = ((i | (i >> 3)) & RCUTORTURE_RDR_MAX_LOOPS) + 1; | |
1248 | for (j = 0; j < i; j++) { | |
2397d072 | 1249 | mask = rcutorture_extend_mask(*readstate, trsp); |
c116dba6 | 1250 | rcutorture_one_extend(readstate, mask, trsp, &rtrsp[j]); |
2397d072 | 1251 | } |
c116dba6 | 1252 | return &rtrsp[j]; |
2397d072 PM |
1253 | } |
1254 | ||
6b06aa72 PM |
1255 | /* |
1256 | * Do one read-side critical section, returning false if there was | |
1257 | * no data to read. Can be invoked both from process context and | |
1258 | * from a timer handler. | |
1259 | */ | |
1260 | static bool rcu_torture_one_read(struct torture_random_state *trsp) | |
0729fbf3 | 1261 | { |
c116dba6 | 1262 | int i; |
917963d0 | 1263 | unsigned long started; |
6b80da42 | 1264 | unsigned long completed; |
2397d072 | 1265 | int newstate; |
0729fbf3 PM |
1266 | struct rcu_torture *p; |
1267 | int pipe_count; | |
2397d072 | 1268 | int readstate = 0; |
c116dba6 PM |
1269 | struct rt_read_seg rtseg[RCUTORTURE_RDR_MAX_SEGS] = { { 0 } }; |
1270 | struct rt_read_seg *rtrsp = &rtseg[0]; | |
1271 | struct rt_read_seg *rtrsp1; | |
52494535 | 1272 | unsigned long long ts; |
0729fbf3 | 1273 | |
2397d072 | 1274 | newstate = rcutorture_extend_mask(readstate, trsp); |
c116dba6 | 1275 | rcutorture_one_extend(&readstate, newstate, trsp, rtrsp++); |
17ef2fe9 | 1276 | started = cur_ops->get_gp_seq(); |
e4aa0da3 | 1277 | ts = rcu_trace_clock_local(); |
632ee200 | 1278 | p = rcu_dereference_check(rcu_torture_current, |
632ee200 PM |
1279 | rcu_read_lock_bh_held() || |
1280 | rcu_read_lock_sched_held() || | |
5be5d1a1 PM |
1281 | srcu_read_lock_held(srcu_ctlp) || |
1282 | torturing_tasks()); | |
0729fbf3 | 1283 | if (p == NULL) { |
6b06aa72 | 1284 | /* Wait for rcu_torture_writer to get underway */ |
c116dba6 | 1285 | rcutorture_one_extend(&readstate, 0, trsp, rtrsp); |
6b06aa72 | 1286 | return false; |
0729fbf3 PM |
1287 | } |
1288 | if (p->rtort_mbtest == 0) | |
1289 | atomic_inc(&n_rcu_torture_mberror); | |
c116dba6 | 1290 | rtrsp = rcutorture_loop_extend(&readstate, trsp, rtrsp); |
0729fbf3 PM |
1291 | preempt_disable(); |
1292 | pipe_count = p->rtort_pipe_count; | |
1293 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
1294 | /* Should not happen, but... */ | |
1295 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
1296 | } | |
17ef2fe9 | 1297 | completed = cur_ops->get_gp_seq(); |
52494535 | 1298 | if (pipe_count > 1) { |
6b06aa72 PM |
1299 | do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, |
1300 | ts, started, completed); | |
274529ba | 1301 | rcu_ftrace_dump(DUMP_ALL); |
52494535 | 1302 | } |
dd17c8f7 | 1303 | __this_cpu_inc(rcu_torture_count[pipe_count]); |
d7219312 | 1304 | completed = rcutorture_seq_diff(completed, started); |
0729fbf3 PM |
1305 | if (completed > RCU_TORTURE_PIPE_LEN) { |
1306 | /* Should not happen, but... */ | |
1307 | completed = RCU_TORTURE_PIPE_LEN; | |
1308 | } | |
dd17c8f7 | 1309 | __this_cpu_inc(rcu_torture_batch[completed]); |
0729fbf3 | 1310 | preempt_enable(); |
c116dba6 | 1311 | rcutorture_one_extend(&readstate, 0, trsp, rtrsp); |
2397d072 | 1312 | WARN_ON_ONCE(readstate & RCUTORTURE_RDR_MASK); |
c116dba6 PM |
1313 | |
1314 | /* If error or close call, record the sequence of reader protections. */ | |
1315 | if ((pipe_count > 1 || completed > 1) && !xchg(&err_segs_recorded, 1)) { | |
1316 | i = 0; | |
1317 | for (rtrsp1 = &rtseg[0]; rtrsp1 < rtrsp; rtrsp1++) | |
1318 | err_segs[i++] = *rtrsp1; | |
1319 | rt_read_nsegs = i; | |
1320 | } | |
1321 | ||
6b06aa72 PM |
1322 | return true; |
1323 | } | |
1324 | ||
3025520e PM |
1325 | static DEFINE_TORTURE_RANDOM_PERCPU(rcu_torture_timer_rand); |
1326 | ||
0729fbf3 PM |
1327 | /* |
1328 | * RCU torture reader from timer handler. Dereferences rcu_torture_current, | |
1329 | * incrementing the corresponding element of the pipeline array. The | |
1330 | * counter in the element should never be greater than 1, otherwise, the | |
1331 | * RCU implementation is broken. | |
1332 | */ | |
fd30b717 | 1333 | static void rcu_torture_timer(struct timer_list *unused) |
0729fbf3 | 1334 | { |
8da9a595 | 1335 | atomic_long_inc(&n_rcu_torture_timers); |
241b4252 | 1336 | (void)rcu_torture_one_read(this_cpu_ptr(&rcu_torture_timer_rand)); |
f34c8585 PM |
1337 | |
1338 | /* Test call_rcu() invocation from interrupt handler. */ | |
1339 | if (cur_ops->call) { | |
1340 | struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_NOWAIT); | |
1341 | ||
1342 | if (rhp) | |
1343 | cur_ops->call(rhp, rcu_torture_timer_cb); | |
1344 | } | |
0729fbf3 PM |
1345 | } |
1346 | ||
a241ec65 PM |
1347 | /* |
1348 | * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, | |
1349 | * incrementing the corresponding element of the pipeline array. The | |
1350 | * counter in the element should never be greater than 1, otherwise, the | |
1351 | * RCU implementation is broken. | |
1352 | */ | |
1353 | static int | |
1354 | rcu_torture_reader(void *arg) | |
1355 | { | |
444da518 | 1356 | unsigned long lastsleep = jiffies; |
c04dd09b PM |
1357 | long myid = (long)arg; |
1358 | int mynumonline = myid; | |
51b1130e | 1359 | DEFINE_TORTURE_RANDOM(rand); |
0729fbf3 | 1360 | struct timer_list t; |
a241ec65 | 1361 | |
5ccf60f2 | 1362 | VERBOSE_TOROUT_STRING("rcu_torture_reader task started"); |
d277d868 | 1363 | set_user_nice(current, MAX_NICE); |
0acc512c | 1364 | if (irqreader && cur_ops->irq_capable) |
fd30b717 | 1365 | timer_setup_on_stack(&t, rcu_torture_timer, 0); |
dbdf65b1 | 1366 | |
a241ec65 | 1367 | do { |
0acc512c | 1368 | if (irqreader && cur_ops->irq_capable) { |
0729fbf3 | 1369 | if (!timer_pending(&t)) |
6155fec9 | 1370 | mod_timer(&t, jiffies + 1); |
0729fbf3 | 1371 | } |
6b06aa72 | 1372 | if (!rcu_torture_one_read(&rand)) |
a241ec65 | 1373 | schedule_timeout_interruptible(HZ); |
444da518 PM |
1374 | if (time_after(jiffies, lastsleep)) { |
1375 | schedule_timeout_interruptible(1); | |
1376 | lastsleep = jiffies + 10; | |
1377 | } | |
c04dd09b PM |
1378 | while (num_online_cpus() < mynumonline && !torture_must_stop()) |
1379 | schedule_timeout_interruptible(HZ / 5); | |
628edaa5 | 1380 | stutter_wait("rcu_torture_reader"); |
36970bb9 | 1381 | } while (!torture_must_stop()); |
424c1b68 | 1382 | if (irqreader && cur_ops->irq_capable) { |
0729fbf3 | 1383 | del_timer_sync(&t); |
424c1b68 TG |
1384 | destroy_timer_on_stack(&t); |
1385 | } | |
7fafaac5 | 1386 | torture_kthread_stopping("rcu_torture_reader"); |
a241ec65 PM |
1387 | return 0; |
1388 | } | |
1389 | ||
1390 | /* | |
eea203fe JP |
1391 | * Print torture statistics. Caller must ensure that there is only |
1392 | * one call to this function at a given time!!! This is normally | |
1393 | * accomplished by relying on the module system to only have one copy | |
1394 | * of the module loaded, and then by giving the rcu_torture_stats | |
1395 | * kthread full control (or the init/cleanup functions when rcu_torture_stats | |
1396 | * thread is not running). | |
a241ec65 | 1397 | */ |
d1008950 | 1398 | static void |
eea203fe | 1399 | rcu_torture_stats_print(void) |
a241ec65 | 1400 | { |
a241ec65 PM |
1401 | int cpu; |
1402 | int i; | |
1403 | long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
1404 | long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
ad0dc7f9 | 1405 | static unsigned long rtcv_snap = ULONG_MAX; |
0032f4e8 | 1406 | static bool splatted; |
4ffa6699 | 1407 | struct task_struct *wtp; |
a241ec65 | 1408 | |
0a945022 | 1409 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
1410 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
1411 | pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i]; | |
1412 | batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i]; | |
1413 | } | |
1414 | } | |
1415 | for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { | |
1416 | if (pipesummary[i] != 0) | |
1417 | break; | |
1418 | } | |
eea203fe JP |
1419 | |
1420 | pr_alert("%s%s ", torture_type, TORTURE_FLAG); | |
354ea05d | 1421 | pr_cont("rtc: %p %s: %lu tfle: %d rta: %d rtaf: %d rtf: %d ", |
eea203fe | 1422 | rcu_torture_current, |
354ea05d | 1423 | rcu_torture_current ? "ver" : "VER", |
eea203fe JP |
1424 | rcu_torture_current_version, |
1425 | list_empty(&rcu_torture_freelist), | |
1426 | atomic_read(&n_rcu_torture_alloc), | |
1427 | atomic_read(&n_rcu_torture_alloc_fail), | |
1428 | atomic_read(&n_rcu_torture_free)); | |
472213a6 | 1429 | pr_cont("rtmbe: %d rtbe: %ld rtbke: %ld rtbre: %ld ", |
eea203fe | 1430 | atomic_read(&n_rcu_torture_mberror), |
472213a6 | 1431 | n_rcu_torture_barrier_error, |
eea203fe JP |
1432 | n_rcu_torture_boost_ktrerror, |
1433 | n_rcu_torture_boost_rterror); | |
1434 | pr_cont("rtbf: %ld rtb: %ld nt: %ld ", | |
1435 | n_rcu_torture_boost_failure, | |
1436 | n_rcu_torture_boosts, | |
8da9a595 | 1437 | atomic_long_read(&n_rcu_torture_timers)); |
eea203fe | 1438 | torture_onoff_stats(); |
fc6f9c57 | 1439 | pr_cont("barrier: %ld/%ld:%ld\n", |
eea203fe JP |
1440 | n_barrier_successes, |
1441 | n_barrier_attempts, | |
1442 | n_rcu_torture_barrier_error); | |
1443 | ||
1444 | pr_alert("%s%s ", torture_type, TORTURE_FLAG); | |
8e8be45e | 1445 | if (atomic_read(&n_rcu_torture_mberror) != 0 || |
fae4b54f | 1446 | n_rcu_torture_barrier_error != 0 || |
8e8be45e PM |
1447 | n_rcu_torture_boost_ktrerror != 0 || |
1448 | n_rcu_torture_boost_rterror != 0 || | |
fae4b54f PM |
1449 | n_rcu_torture_boost_failure != 0 || |
1450 | i > 1) { | |
eea203fe | 1451 | pr_cont("%s", "!!! "); |
996417d2 | 1452 | atomic_inc(&n_rcu_torture_error); |
5af970a4 | 1453 | WARN_ON_ONCE(1); |
996417d2 | 1454 | } |
eea203fe | 1455 | pr_cont("Reader Pipe: "); |
a241ec65 | 1456 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
eea203fe JP |
1457 | pr_cont(" %ld", pipesummary[i]); |
1458 | pr_cont("\n"); | |
1459 | ||
1460 | pr_alert("%s%s ", torture_type, TORTURE_FLAG); | |
1461 | pr_cont("Reader Batch: "); | |
72e9bb54 | 1462 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
eea203fe JP |
1463 | pr_cont(" %ld", batchsummary[i]); |
1464 | pr_cont("\n"); | |
1465 | ||
1466 | pr_alert("%s%s ", torture_type, TORTURE_FLAG); | |
1467 | pr_cont("Free-Block Circulation: "); | |
a241ec65 | 1468 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
eea203fe | 1469 | pr_cont(" %d", atomic_read(&rcu_torture_wcount[i])); |
a241ec65 | 1470 | } |
eea203fe JP |
1471 | pr_cont("\n"); |
1472 | ||
c8e5b163 | 1473 | if (cur_ops->stats) |
eea203fe | 1474 | cur_ops->stats(); |
ad0dc7f9 PM |
1475 | if (rtcv_snap == rcu_torture_current_version && |
1476 | rcu_torture_current != NULL) { | |
7f6733c3 | 1477 | int __maybe_unused flags = 0; |
aebc8264 | 1478 | unsigned long __maybe_unused gp_seq = 0; |
ad0dc7f9 PM |
1479 | |
1480 | rcutorture_get_gp_data(cur_ops->ttype, | |
aebc8264 | 1481 | &flags, &gp_seq); |
7f6733c3 | 1482 | srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, |
aebc8264 | 1483 | &flags, &gp_seq); |
4ffa6699 | 1484 | wtp = READ_ONCE(writer_task); |
aebc8264 | 1485 | pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#lx cpu %d\n", |
18aff33e | 1486 | rcu_torture_writer_state_getname(), |
aebc8264 | 1487 | rcu_torture_writer_state, gp_seq, flags, |
808de39c PM |
1488 | wtp == NULL ? ~0UL : wtp->state, |
1489 | wtp == NULL ? -1 : (int)task_cpu(wtp)); | |
0032f4e8 PM |
1490 | if (!splatted && wtp) { |
1491 | sched_show_task(wtp); | |
1492 | splatted = true; | |
1493 | } | |
afea227f | 1494 | show_rcu_gp_kthreads(); |
274529ba | 1495 | rcu_ftrace_dump(DUMP_ALL); |
ad0dc7f9 PM |
1496 | } |
1497 | rtcv_snap = rcu_torture_current_version; | |
a241ec65 PM |
1498 | } |
1499 | ||
a241ec65 PM |
1500 | /* |
1501 | * Periodically prints torture statistics, if periodic statistics printing | |
1502 | * was specified via the stat_interval module parameter. | |
a241ec65 PM |
1503 | */ |
1504 | static int | |
1505 | rcu_torture_stats(void *arg) | |
1506 | { | |
5ccf60f2 | 1507 | VERBOSE_TOROUT_STRING("rcu_torture_stats task started"); |
a241ec65 PM |
1508 | do { |
1509 | schedule_timeout_interruptible(stat_interval * HZ); | |
1510 | rcu_torture_stats_print(); | |
f67a3356 | 1511 | torture_shutdown_absorb("rcu_torture_stats"); |
36970bb9 | 1512 | } while (!torture_must_stop()); |
7fafaac5 | 1513 | torture_kthread_stopping("rcu_torture_stats"); |
d120f65f PM |
1514 | return 0; |
1515 | } | |
1516 | ||
eac45e58 | 1517 | static void |
e66c33d5 | 1518 | rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag) |
95c38322 | 1519 | { |
2caa1e44 PM |
1520 | pr_alert("%s" TORTURE_FLAG |
1521 | "--- %s: nreaders=%d nfakewriters=%d " | |
1522 | "stat_interval=%d verbose=%d test_no_idle_hz=%d " | |
1523 | "shuffle_interval=%d stutter=%d irqreader=%d " | |
1524 | "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d " | |
1525 | "test_boost=%d/%d test_boost_interval=%d " | |
1526 | "test_boost_duration=%d shutdown_secs=%d " | |
2b1516e5 | 1527 | "stall_cpu=%d stall_cpu_holdoff=%d stall_cpu_irqsoff=%d " |
67afeed2 | 1528 | "n_barrier_cbs=%d " |
2caa1e44 PM |
1529 | "onoff_interval=%d onoff_holdoff=%d\n", |
1530 | torture_type, tag, nrealreaders, nfakewriters, | |
1531 | stat_interval, verbose, test_no_idle_hz, shuffle_interval, | |
1532 | stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter, | |
1533 | test_boost, cur_ops->can_boost, | |
1534 | test_boost_interval, test_boost_duration, shutdown_secs, | |
2b1516e5 | 1535 | stall_cpu, stall_cpu_holdoff, stall_cpu_irqsoff, |
67afeed2 | 1536 | n_barrier_cbs, |
2caa1e44 | 1537 | onoff_interval, onoff_holdoff); |
95c38322 PM |
1538 | } |
1539 | ||
0ffd374b | 1540 | static int rcutorture_booster_cleanup(unsigned int cpu) |
8e8be45e PM |
1541 | { |
1542 | struct task_struct *t; | |
1543 | ||
1544 | if (boost_tasks[cpu] == NULL) | |
0ffd374b | 1545 | return 0; |
8e8be45e | 1546 | mutex_lock(&boost_mutex); |
8e8be45e PM |
1547 | t = boost_tasks[cpu]; |
1548 | boost_tasks[cpu] = NULL; | |
450efca7 | 1549 | rcu_torture_enable_rt_throttle(); |
8e8be45e PM |
1550 | mutex_unlock(&boost_mutex); |
1551 | ||
1552 | /* This must be outside of the mutex, otherwise deadlock! */ | |
9c029b86 | 1553 | torture_stop_kthread(rcu_torture_boost, t); |
0ffd374b | 1554 | return 0; |
8e8be45e PM |
1555 | } |
1556 | ||
0ffd374b | 1557 | static int rcutorture_booster_init(unsigned int cpu) |
8e8be45e PM |
1558 | { |
1559 | int retval; | |
1560 | ||
1561 | if (boost_tasks[cpu] != NULL) | |
1562 | return 0; /* Already created, nothing more to do. */ | |
1563 | ||
1564 | /* Don't allow time recalculation while creating a new task. */ | |
1565 | mutex_lock(&boost_mutex); | |
450efca7 | 1566 | rcu_torture_disable_rt_throttle(); |
5ccf60f2 | 1567 | VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task"); |
1f288094 ED |
1568 | boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL, |
1569 | cpu_to_node(cpu), | |
1570 | "rcu_torture_boost"); | |
8e8be45e PM |
1571 | if (IS_ERR(boost_tasks[cpu])) { |
1572 | retval = PTR_ERR(boost_tasks[cpu]); | |
5ccf60f2 | 1573 | VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed"); |
8e8be45e PM |
1574 | n_rcu_torture_boost_ktrerror++; |
1575 | boost_tasks[cpu] = NULL; | |
1576 | mutex_unlock(&boost_mutex); | |
1577 | return retval; | |
1578 | } | |
1579 | kthread_bind(boost_tasks[cpu], cpu); | |
1580 | wake_up_process(boost_tasks[cpu]); | |
1581 | mutex_unlock(&boost_mutex); | |
1582 | return 0; | |
1583 | } | |
1584 | ||
c13f3757 PM |
1585 | /* |
1586 | * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then | |
1587 | * induces a CPU stall for the time specified by stall_cpu. | |
1588 | */ | |
49fb4c62 | 1589 | static int rcu_torture_stall(void *args) |
c13f3757 PM |
1590 | { |
1591 | unsigned long stop_at; | |
1592 | ||
5ccf60f2 | 1593 | VERBOSE_TOROUT_STRING("rcu_torture_stall task started"); |
c13f3757 | 1594 | if (stall_cpu_holdoff > 0) { |
5ccf60f2 | 1595 | VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff"); |
c13f3757 | 1596 | schedule_timeout_interruptible(stall_cpu_holdoff * HZ); |
5ccf60f2 | 1597 | VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff"); |
c13f3757 PM |
1598 | } |
1599 | if (!kthread_should_stop()) { | |
622be33f | 1600 | stop_at = ktime_get_seconds() + stall_cpu; |
c13f3757 | 1601 | /* RCU CPU stall is expected behavior in following code. */ |
c13f3757 | 1602 | rcu_read_lock(); |
2b1516e5 PM |
1603 | if (stall_cpu_irqsoff) |
1604 | local_irq_disable(); | |
1605 | else | |
1606 | preempt_disable(); | |
1607 | pr_alert("rcu_torture_stall start on CPU %d.\n", | |
1608 | smp_processor_id()); | |
622be33f AB |
1609 | while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(), |
1610 | stop_at)) | |
c13f3757 | 1611 | continue; /* Induce RCU CPU stall warning. */ |
2b1516e5 PM |
1612 | if (stall_cpu_irqsoff) |
1613 | local_irq_enable(); | |
1614 | else | |
1615 | preempt_enable(); | |
c13f3757 | 1616 | rcu_read_unlock(); |
2caa1e44 | 1617 | pr_alert("rcu_torture_stall end.\n"); |
c13f3757 | 1618 | } |
f67a3356 | 1619 | torture_shutdown_absorb("rcu_torture_stall"); |
c13f3757 PM |
1620 | while (!kthread_should_stop()) |
1621 | schedule_timeout_interruptible(10 * HZ); | |
1622 | return 0; | |
1623 | } | |
1624 | ||
1625 | /* Spawn CPU-stall kthread, if stall_cpu specified. */ | |
1626 | static int __init rcu_torture_stall_init(void) | |
1627 | { | |
c13f3757 PM |
1628 | if (stall_cpu <= 0) |
1629 | return 0; | |
47cf29b9 | 1630 | return torture_create_kthread(rcu_torture_stall, NULL, stall_task); |
c13f3757 PM |
1631 | } |
1632 | ||
9fdcb9af PM |
1633 | /* State structure for forward-progress self-propagating RCU callback. */ |
1634 | struct fwd_cb_state { | |
1635 | struct rcu_head rh; | |
1636 | int stop; | |
1637 | }; | |
1638 | ||
1639 | /* | |
1640 | * Forward-progress self-propagating RCU callback function. Because | |
1641 | * callbacks run from softirq, this function is an implicit RCU read-side | |
1642 | * critical section. | |
1643 | */ | |
1644 | static void rcu_torture_fwd_prog_cb(struct rcu_head *rhp) | |
1645 | { | |
1646 | struct fwd_cb_state *fcsp = container_of(rhp, struct fwd_cb_state, rh); | |
1647 | ||
1648 | if (READ_ONCE(fcsp->stop)) { | |
1649 | WRITE_ONCE(fcsp->stop, 2); | |
1650 | return; | |
1651 | } | |
1652 | cur_ops->call(&fcsp->rh, rcu_torture_fwd_prog_cb); | |
1653 | } | |
1654 | ||
48718485 PM |
1655 | /* State for continuous-flood RCU callbacks. */ |
1656 | struct rcu_fwd_cb { | |
1657 | struct rcu_head rh; | |
1658 | struct rcu_fwd_cb *rfc_next; | |
1659 | int rfc_gps; | |
1660 | }; | |
1661 | static DEFINE_SPINLOCK(rcu_fwd_lock); | |
1662 | static struct rcu_fwd_cb *rcu_fwd_cb_head; | |
1663 | static struct rcu_fwd_cb **rcu_fwd_cb_tail = &rcu_fwd_cb_head; | |
1664 | static long n_launders_cb; | |
1665 | static unsigned long rcu_fwd_startat; | |
e0aff973 | 1666 | static bool rcu_fwd_emergency_stop; |
48718485 PM |
1667 | #define MAX_FWD_CB_JIFFIES (8 * HZ) /* Maximum CB test duration. */ |
1668 | #define MIN_FWD_CB_LAUNDERS 3 /* This many CB invocations to count. */ | |
1669 | #define MIN_FWD_CBS_LAUNDERED 100 /* Number of counted CBs. */ | |
2e57bf97 | 1670 | #define FWD_CBS_HIST_DIV 10 /* Histogram buckets/second. */ |
cd618d10 PM |
1671 | struct rcu_launder_hist { |
1672 | long n_launders; | |
1673 | unsigned long launder_gp_seq; | |
1674 | }; | |
1675 | #define N_LAUNDERS_HIST (2 * MAX_FWD_CB_JIFFIES / (HZ / FWD_CBS_HIST_DIV)) | |
1676 | static struct rcu_launder_hist n_launders_hist[N_LAUNDERS_HIST]; | |
1677 | static unsigned long rcu_launder_gp_seq_start; | |
48718485 | 1678 | |
1a682754 PM |
1679 | static void rcu_torture_fwd_cb_hist(void) |
1680 | { | |
cd618d10 PM |
1681 | unsigned long gps; |
1682 | unsigned long gps_old; | |
1a682754 PM |
1683 | int i; |
1684 | int j; | |
1685 | ||
1686 | for (i = ARRAY_SIZE(n_launders_hist) - 1; i > 0; i--) | |
cd618d10 | 1687 | if (n_launders_hist[i].n_launders > 0) |
1a682754 | 1688 | break; |
73d665b1 PM |
1689 | pr_alert("%s: Callback-invocation histogram (duration %lu jiffies):", |
1690 | __func__, jiffies - rcu_fwd_startat); | |
cd618d10 PM |
1691 | gps_old = rcu_launder_gp_seq_start; |
1692 | for (j = 0; j <= i; j++) { | |
1693 | gps = n_launders_hist[j].launder_gp_seq; | |
1694 | pr_cont(" %ds/%d: %ld:%ld", | |
1695 | j + 1, FWD_CBS_HIST_DIV, n_launders_hist[j].n_launders, | |
1696 | rcutorture_seq_diff(gps, gps_old)); | |
1697 | gps_old = gps; | |
1698 | } | |
1a682754 PM |
1699 | pr_cont("\n"); |
1700 | } | |
1701 | ||
48718485 PM |
1702 | /* Callback function for continuous-flood RCU callbacks. */ |
1703 | static void rcu_torture_fwd_cb_cr(struct rcu_head *rhp) | |
1704 | { | |
2667ccce | 1705 | unsigned long flags; |
48718485 PM |
1706 | int i; |
1707 | struct rcu_fwd_cb *rfcp = container_of(rhp, struct rcu_fwd_cb, rh); | |
1708 | struct rcu_fwd_cb **rfcpp; | |
1709 | ||
1710 | rfcp->rfc_next = NULL; | |
1711 | rfcp->rfc_gps++; | |
2667ccce | 1712 | spin_lock_irqsave(&rcu_fwd_lock, flags); |
48718485 PM |
1713 | rfcpp = rcu_fwd_cb_tail; |
1714 | rcu_fwd_cb_tail = &rfcp->rfc_next; | |
1715 | WRITE_ONCE(*rfcpp, rfcp); | |
1716 | WRITE_ONCE(n_launders_cb, n_launders_cb + 1); | |
2e57bf97 | 1717 | i = ((jiffies - rcu_fwd_startat) / (HZ / FWD_CBS_HIST_DIV)); |
48718485 PM |
1718 | if (i >= ARRAY_SIZE(n_launders_hist)) |
1719 | i = ARRAY_SIZE(n_launders_hist) - 1; | |
cd618d10 PM |
1720 | n_launders_hist[i].n_launders++; |
1721 | n_launders_hist[i].launder_gp_seq = cur_ops->get_gp_seq(); | |
2667ccce PM |
1722 | spin_unlock_irqrestore(&rcu_fwd_lock, flags); |
1723 | } | |
1724 | ||
ab21f608 | 1725 | // Give the scheduler a chance, even on nohz_full CPUs. |
bd1bfc51 | 1726 | static void rcu_torture_fwd_prog_cond_resched(unsigned long iter) |
ab21f608 PM |
1727 | { |
1728 | if (IS_ENABLED(CONFIG_PREEMPT) && IS_ENABLED(CONFIG_NO_HZ_FULL)) { | |
bd1bfc51 PM |
1729 | // Real call_rcu() floods hit userspace, so emulate that. |
1730 | if (need_resched() || (iter & 0xfff)) | |
ab21f608 PM |
1731 | schedule(); |
1732 | } else { | |
bd1bfc51 | 1733 | // No userspace emulation: CB invocation throttles call_rcu() |
ab21f608 PM |
1734 | cond_resched(); |
1735 | } | |
1736 | } | |
1737 | ||
2667ccce PM |
1738 | /* |
1739 | * Free all callbacks on the rcu_fwd_cb_head list, either because the | |
1740 | * test is over or because we hit an OOM event. | |
1741 | */ | |
1742 | static unsigned long rcu_torture_fwd_prog_cbfree(void) | |
1743 | { | |
1744 | unsigned long flags; | |
1745 | unsigned long freed = 0; | |
1746 | struct rcu_fwd_cb *rfcp; | |
1747 | ||
1748 | for (;;) { | |
1749 | spin_lock_irqsave(&rcu_fwd_lock, flags); | |
1750 | rfcp = rcu_fwd_cb_head; | |
140e53f2 PM |
1751 | if (!rfcp) { |
1752 | spin_unlock_irqrestore(&rcu_fwd_lock, flags); | |
2667ccce | 1753 | break; |
140e53f2 | 1754 | } |
2667ccce PM |
1755 | rcu_fwd_cb_head = rfcp->rfc_next; |
1756 | if (!rcu_fwd_cb_head) | |
1757 | rcu_fwd_cb_tail = &rcu_fwd_cb_head; | |
1758 | spin_unlock_irqrestore(&rcu_fwd_lock, flags); | |
1759 | kfree(rfcp); | |
1760 | freed++; | |
bd1bfc51 | 1761 | rcu_torture_fwd_prog_cond_resched(freed); |
2667ccce | 1762 | } |
2667ccce | 1763 | return freed; |
48718485 PM |
1764 | } |
1765 | ||
6b3de7a1 PM |
1766 | /* Carry out need_resched()/cond_resched() forward-progress testing. */ |
1767 | static void rcu_torture_fwd_prog_nr(int *tested, int *tested_tries) | |
1b27291b | 1768 | { |
119248be | 1769 | unsigned long cver; |
f4de46ed | 1770 | unsigned long dur; |
7c590fcc | 1771 | struct fwd_cb_state fcs; |
119248be | 1772 | unsigned long gps; |
1b27291b | 1773 | int idx; |
6b3de7a1 PM |
1774 | int sd; |
1775 | int sd4; | |
1776 | bool selfpropcb = false; | |
1777 | unsigned long stopat; | |
1778 | static DEFINE_TORTURE_RANDOM(trs); | |
1779 | ||
1780 | if (cur_ops->call && cur_ops->sync && cur_ops->cb_barrier) { | |
1781 | init_rcu_head_on_stack(&fcs.rh); | |
1782 | selfpropcb = true; | |
1783 | } | |
1784 | ||
1785 | /* Tight loop containing cond_resched(). */ | |
e8516c64 PM |
1786 | WRITE_ONCE(rcu_fwd_cb_nodelay, true); |
1787 | cur_ops->sync(); /* Later readers see above write. */ | |
6b3de7a1 PM |
1788 | if (selfpropcb) { |
1789 | WRITE_ONCE(fcs.stop, 0); | |
1790 | cur_ops->call(&fcs.rh, rcu_torture_fwd_prog_cb); | |
1791 | } | |
1792 | cver = READ_ONCE(rcu_torture_current_version); | |
1793 | gps = cur_ops->get_gp_seq(); | |
1794 | sd = cur_ops->stall_dur() + 1; | |
1795 | sd4 = (sd + fwd_progress_div - 1) / fwd_progress_div; | |
1796 | dur = sd4 + torture_random(&trs) % (sd - sd4); | |
61670adc | 1797 | WRITE_ONCE(rcu_fwd_startat, jiffies); |
6b3de7a1 | 1798 | stopat = rcu_fwd_startat + dur; |
e0aff973 | 1799 | while (time_before(jiffies, stopat) && |
60013d5d | 1800 | !shutdown_time_arrived() && |
e0aff973 | 1801 | !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { |
6b3de7a1 PM |
1802 | idx = cur_ops->readlock(); |
1803 | udelay(10); | |
1804 | cur_ops->readunlock(idx); | |
1805 | if (!fwd_progress_need_resched || need_resched()) | |
bd1bfc51 | 1806 | rcu_torture_fwd_prog_cond_resched(1); |
6b3de7a1 PM |
1807 | } |
1808 | (*tested_tries)++; | |
e0aff973 | 1809 | if (!time_before(jiffies, stopat) && |
60013d5d | 1810 | !shutdown_time_arrived() && |
e0aff973 | 1811 | !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { |
6b3de7a1 PM |
1812 | (*tested)++; |
1813 | cver = READ_ONCE(rcu_torture_current_version) - cver; | |
1814 | gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps); | |
1815 | WARN_ON(!cver && gps < 2); | |
1816 | pr_alert("%s: Duration %ld cver %ld gps %ld\n", __func__, dur, cver, gps); | |
1817 | } | |
1818 | if (selfpropcb) { | |
1819 | WRITE_ONCE(fcs.stop, 1); | |
1820 | cur_ops->sync(); /* Wait for running CB to complete. */ | |
1821 | cur_ops->cb_barrier(); /* Wait for queued callbacks. */ | |
1822 | } | |
1823 | ||
1824 | if (selfpropcb) { | |
1825 | WARN_ON(READ_ONCE(fcs.stop) != 2); | |
1826 | destroy_rcu_head_on_stack(&fcs.rh); | |
1827 | } | |
e8516c64 PM |
1828 | schedule_timeout_uninterruptible(HZ / 10); /* Let kthreads recover. */ |
1829 | WRITE_ONCE(rcu_fwd_cb_nodelay, false); | |
6b3de7a1 PM |
1830 | } |
1831 | ||
1832 | /* Carry out call_rcu() forward-progress testing. */ | |
1833 | static void rcu_torture_fwd_prog_cr(void) | |
1834 | { | |
1835 | unsigned long cver; | |
1836 | unsigned long gps; | |
1837 | int i; | |
48718485 PM |
1838 | long n_launders; |
1839 | long n_launders_cb_snap; | |
1840 | long n_launders_sa; | |
1841 | long n_max_cbs; | |
1842 | long n_max_gps; | |
1843 | struct rcu_fwd_cb *rfcp; | |
1844 | struct rcu_fwd_cb *rfcpn; | |
1b27291b | 1845 | unsigned long stopat; |
48718485 | 1846 | unsigned long stoppedat; |
6b3de7a1 | 1847 | |
2667ccce PM |
1848 | if (READ_ONCE(rcu_fwd_emergency_stop)) |
1849 | return; /* Get out of the way quickly, no GP wait! */ | |
c682db55 PM |
1850 | if (!cur_ops->call) |
1851 | return; /* Can't do call_rcu() fwd prog without ->call. */ | |
2667ccce | 1852 | |
6b3de7a1 PM |
1853 | /* Loop continuously posting RCU callbacks. */ |
1854 | WRITE_ONCE(rcu_fwd_cb_nodelay, true); | |
1855 | cur_ops->sync(); /* Later readers see above write. */ | |
61670adc | 1856 | WRITE_ONCE(rcu_fwd_startat, jiffies); |
6b3de7a1 PM |
1857 | stopat = rcu_fwd_startat + MAX_FWD_CB_JIFFIES; |
1858 | n_launders = 0; | |
1859 | n_launders_cb = 0; | |
1860 | n_launders_sa = 0; | |
1861 | n_max_cbs = 0; | |
1862 | n_max_gps = 0; | |
1863 | for (i = 0; i < ARRAY_SIZE(n_launders_hist); i++) | |
cd618d10 | 1864 | n_launders_hist[i].n_launders = 0; |
6b3de7a1 PM |
1865 | cver = READ_ONCE(rcu_torture_current_version); |
1866 | gps = cur_ops->get_gp_seq(); | |
cd618d10 | 1867 | rcu_launder_gp_seq_start = gps; |
e0aff973 | 1868 | while (time_before(jiffies, stopat) && |
60013d5d | 1869 | !shutdown_time_arrived() && |
e0aff973 | 1870 | !READ_ONCE(rcu_fwd_emergency_stop) && !torture_must_stop()) { |
6b3de7a1 PM |
1871 | rfcp = READ_ONCE(rcu_fwd_cb_head); |
1872 | rfcpn = NULL; | |
1873 | if (rfcp) | |
1874 | rfcpn = READ_ONCE(rfcp->rfc_next); | |
1875 | if (rfcpn) { | |
1876 | if (rfcp->rfc_gps >= MIN_FWD_CB_LAUNDERS && | |
1877 | ++n_max_gps >= MIN_FWD_CBS_LAUNDERED) | |
1878 | break; | |
1879 | rcu_fwd_cb_head = rfcpn; | |
1880 | n_launders++; | |
1881 | n_launders_sa++; | |
1882 | } else { | |
1883 | rfcp = kmalloc(sizeof(*rfcp), GFP_KERNEL); | |
1884 | if (WARN_ON_ONCE(!rfcp)) { | |
1885 | schedule_timeout_interruptible(1); | |
1886 | continue; | |
1887 | } | |
1888 | n_max_cbs++; | |
1889 | n_launders_sa = 0; | |
1890 | rfcp->rfc_gps = 0; | |
1891 | } | |
1892 | cur_ops->call(&rfcp->rh, rcu_torture_fwd_cb_cr); | |
bd1bfc51 | 1893 | rcu_torture_fwd_prog_cond_resched(n_launders + n_max_cbs); |
6b3de7a1 PM |
1894 | } |
1895 | stoppedat = jiffies; | |
1896 | n_launders_cb_snap = READ_ONCE(n_launders_cb); | |
1897 | cver = READ_ONCE(rcu_torture_current_version) - cver; | |
1898 | gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps); | |
1899 | cur_ops->cb_barrier(); /* Wait for callbacks to be invoked. */ | |
2667ccce PM |
1900 | (void)rcu_torture_fwd_prog_cbfree(); |
1901 | ||
60013d5d PM |
1902 | if (!torture_must_stop() && !READ_ONCE(rcu_fwd_emergency_stop) && |
1903 | !shutdown_time_arrived()) { | |
6b3de7a1 PM |
1904 | WARN_ON(n_max_gps < MIN_FWD_CBS_LAUNDERED); |
1905 | pr_alert("%s Duration %lu barrier: %lu pending %ld n_launders: %ld n_launders_sa: %ld n_max_gps: %ld n_max_cbs: %ld cver %ld gps %ld\n", | |
1906 | __func__, | |
1907 | stoppedat - rcu_fwd_startat, jiffies - stoppedat, | |
1908 | n_launders + n_max_cbs - n_launders_cb_snap, | |
1909 | n_launders, n_launders_sa, | |
1910 | n_max_gps, n_max_cbs, cver, gps); | |
1a682754 | 1911 | rcu_torture_fwd_cb_hist(); |
6b3de7a1 | 1912 | } |
e8516c64 PM |
1913 | schedule_timeout_uninterruptible(HZ); /* Let CBs drain. */ |
1914 | WRITE_ONCE(rcu_fwd_cb_nodelay, false); | |
6b3de7a1 PM |
1915 | } |
1916 | ||
e0aff973 PM |
1917 | |
1918 | /* | |
1919 | * OOM notifier, but this only prints diagnostic information for the | |
1920 | * current forward-progress test. | |
1921 | */ | |
1922 | static int rcutorture_oom_notify(struct notifier_block *self, | |
1923 | unsigned long notused, void *nfreed) | |
1924 | { | |
2667ccce PM |
1925 | WARN(1, "%s invoked upon OOM during forward-progress testing.\n", |
1926 | __func__); | |
1a682754 | 1927 | rcu_torture_fwd_cb_hist(); |
d44ac1be | 1928 | rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rcu_fwd_startat)) / 2); |
e0aff973 | 1929 | WRITE_ONCE(rcu_fwd_emergency_stop, true); |
2667ccce PM |
1930 | smp_mb(); /* Emergency stop before free and wait to avoid hangs. */ |
1931 | pr_info("%s: Freed %lu RCU callbacks.\n", | |
1932 | __func__, rcu_torture_fwd_prog_cbfree()); | |
1933 | rcu_barrier(); | |
1934 | pr_info("%s: Freed %lu RCU callbacks.\n", | |
1935 | __func__, rcu_torture_fwd_prog_cbfree()); | |
1936 | rcu_barrier(); | |
1937 | pr_info("%s: Freed %lu RCU callbacks.\n", | |
1938 | __func__, rcu_torture_fwd_prog_cbfree()); | |
1939 | smp_mb(); /* Frees before return to avoid redoing OOM. */ | |
1940 | (*(unsigned long *)nfreed)++; /* Forward progress CBs freed! */ | |
1941 | pr_info("%s returning after OOM processing.\n", __func__); | |
e0aff973 PM |
1942 | return NOTIFY_OK; |
1943 | } | |
1944 | ||
1945 | static struct notifier_block rcutorture_oom_nb = { | |
1946 | .notifier_call = rcutorture_oom_notify | |
1947 | }; | |
1948 | ||
6b3de7a1 PM |
1949 | /* Carry out grace-period forward-progress testing. */ |
1950 | static int rcu_torture_fwd_prog(void *args) | |
1951 | { | |
f4de46ed | 1952 | int tested = 0; |
152f4afb | 1953 | int tested_tries = 0; |
1b27291b PM |
1954 | |
1955 | VERBOSE_TOROUT_STRING("rcu_torture_fwd_progress task started"); | |
5ab7ab83 | 1956 | rcu_bind_current_to_nocb(); |
fecad509 PM |
1957 | if (!IS_ENABLED(CONFIG_SMP) || !IS_ENABLED(CONFIG_RCU_BOOST)) |
1958 | set_user_nice(current, MAX_NICE); | |
1b27291b PM |
1959 | do { |
1960 | schedule_timeout_interruptible(fwd_progress_holdoff * HZ); | |
e0aff973 PM |
1961 | WRITE_ONCE(rcu_fwd_emergency_stop, false); |
1962 | register_oom_notifier(&rcutorture_oom_nb); | |
6b3de7a1 PM |
1963 | rcu_torture_fwd_prog_nr(&tested, &tested_tries); |
1964 | rcu_torture_fwd_prog_cr(); | |
e0aff973 | 1965 | unregister_oom_notifier(&rcutorture_oom_nb); |
48718485 | 1966 | |
1b27291b PM |
1967 | /* Avoid slow periods, better to test when busy. */ |
1968 | stutter_wait("rcu_torture_fwd_prog"); | |
1969 | } while (!torture_must_stop()); | |
152f4afb PM |
1970 | /* Short runs might not contain a valid forward-progress attempt. */ |
1971 | WARN_ON(!tested && tested_tries >= 5); | |
f4de46ed | 1972 | pr_alert("%s: tested %d tested_tries %d\n", __func__, tested, tested_tries); |
1b27291b PM |
1973 | torture_kthread_stopping("rcu_torture_fwd_prog"); |
1974 | return 0; | |
1975 | } | |
1976 | ||
1977 | /* If forward-progress checking is requested and feasible, spawn the thread. */ | |
1978 | static int __init rcu_torture_fwd_prog_init(void) | |
1979 | { | |
1980 | if (!fwd_progress) | |
1981 | return 0; /* Not requested, so don't do it. */ | |
5ac7cdc2 PM |
1982 | if (!cur_ops->stall_dur || cur_ops->stall_dur() <= 0 || |
1983 | cur_ops == &rcu_busted_ops) { | |
1b27291b PM |
1984 | VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, unsupported by RCU flavor under test"); |
1985 | return 0; | |
1986 | } | |
1987 | if (stall_cpu > 0) { | |
1988 | VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, conflicts with CPU-stall testing"); | |
1989 | if (IS_MODULE(CONFIG_RCU_TORTURE_TESTS)) | |
1990 | return -EINVAL; /* In module, can fail back to user. */ | |
1991 | WARN_ON(1); /* Make sure rcutorture notices conflict. */ | |
1992 | return 0; | |
1993 | } | |
1994 | if (fwd_progress_holdoff <= 0) | |
1995 | fwd_progress_holdoff = 1; | |
1996 | if (fwd_progress_div <= 0) | |
1997 | fwd_progress_div = 4; | |
1998 | return torture_create_kthread(rcu_torture_fwd_prog, | |
1999 | NULL, fwd_prog_task); | |
2000 | } | |
2001 | ||
fae4b54f | 2002 | /* Callback function for RCU barrier testing. */ |
b3b8a4d4 | 2003 | static void rcu_torture_barrier_cbf(struct rcu_head *rcu) |
fae4b54f PM |
2004 | { |
2005 | atomic_inc(&barrier_cbs_invoked); | |
2006 | } | |
2007 | ||
2008 | /* kthread function to register callbacks used to test RCU barriers. */ | |
2009 | static int rcu_torture_barrier_cbs(void *arg) | |
2010 | { | |
2011 | long myid = (long)arg; | |
c6ebcbb6 | 2012 | bool lastphase = 0; |
78e4bc34 | 2013 | bool newphase; |
fae4b54f PM |
2014 | struct rcu_head rcu; |
2015 | ||
2016 | init_rcu_head_on_stack(&rcu); | |
5ccf60f2 | 2017 | VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started"); |
d277d868 | 2018 | set_user_nice(current, MAX_NICE); |
fae4b54f PM |
2019 | do { |
2020 | wait_event(barrier_cbs_wq[myid], | |
78e4bc34 | 2021 | (newphase = |
6c7ed42c | 2022 | smp_load_acquire(&barrier_phase)) != lastphase || |
36970bb9 | 2023 | torture_must_stop()); |
78e4bc34 | 2024 | lastphase = newphase; |
36970bb9 | 2025 | if (torture_must_stop()) |
fae4b54f | 2026 | break; |
6c7ed42c PM |
2027 | /* |
2028 | * The above smp_load_acquire() ensures barrier_phase load | |
aab05738 | 2029 | * is ordered before the following ->call(). |
6c7ed42c | 2030 | */ |
0aa67e75 | 2031 | local_irq_disable(); /* Just to test no-irq call_rcu(). */ |
fae4b54f | 2032 | cur_ops->call(&rcu, rcu_torture_barrier_cbf); |
0aa67e75 | 2033 | local_irq_enable(); |
fae4b54f PM |
2034 | if (atomic_dec_and_test(&barrier_cbs_count)) |
2035 | wake_up(&barrier_wq); | |
36970bb9 | 2036 | } while (!torture_must_stop()); |
69c60455 PM |
2037 | if (cur_ops->cb_barrier != NULL) |
2038 | cur_ops->cb_barrier(); | |
fae4b54f | 2039 | destroy_rcu_head_on_stack(&rcu); |
7fafaac5 | 2040 | torture_kthread_stopping("rcu_torture_barrier_cbs"); |
fae4b54f PM |
2041 | return 0; |
2042 | } | |
2043 | ||
2044 | /* kthread function to drive and coordinate RCU barrier testing. */ | |
2045 | static int rcu_torture_barrier(void *arg) | |
2046 | { | |
2047 | int i; | |
2048 | ||
5ccf60f2 | 2049 | VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting"); |
fae4b54f PM |
2050 | do { |
2051 | atomic_set(&barrier_cbs_invoked, 0); | |
2052 | atomic_set(&barrier_cbs_count, n_barrier_cbs); | |
6c7ed42c PM |
2053 | /* Ensure barrier_phase ordered after prior assignments. */ |
2054 | smp_store_release(&barrier_phase, !barrier_phase); | |
fae4b54f PM |
2055 | for (i = 0; i < n_barrier_cbs; i++) |
2056 | wake_up(&barrier_cbs_wq[i]); | |
2057 | wait_event(barrier_wq, | |
2058 | atomic_read(&barrier_cbs_count) == 0 || | |
36970bb9 PM |
2059 | torture_must_stop()); |
2060 | if (torture_must_stop()) | |
fae4b54f PM |
2061 | break; |
2062 | n_barrier_attempts++; | |
78e4bc34 | 2063 | cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */ |
fae4b54f PM |
2064 | if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) { |
2065 | n_rcu_torture_barrier_error++; | |
7602de4a PM |
2066 | pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n", |
2067 | atomic_read(&barrier_cbs_invoked), | |
2068 | n_barrier_cbs); | |
fae4b54f | 2069 | WARN_ON_ONCE(1); |
bf5b6435 JFG |
2070 | } else { |
2071 | n_barrier_successes++; | |
fae4b54f | 2072 | } |
fae4b54f | 2073 | schedule_timeout_interruptible(HZ / 10); |
36970bb9 | 2074 | } while (!torture_must_stop()); |
7fafaac5 | 2075 | torture_kthread_stopping("rcu_torture_barrier"); |
fae4b54f PM |
2076 | return 0; |
2077 | } | |
2078 | ||
2079 | /* Initialize RCU barrier testing. */ | |
2080 | static int rcu_torture_barrier_init(void) | |
2081 | { | |
2082 | int i; | |
2083 | int ret; | |
2084 | ||
d9eba768 | 2085 | if (n_barrier_cbs <= 0) |
fae4b54f PM |
2086 | return 0; |
2087 | if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) { | |
2caa1e44 PM |
2088 | pr_alert("%s" TORTURE_FLAG |
2089 | " Call or barrier ops missing for %s,\n", | |
2090 | torture_type, cur_ops->name); | |
2091 | pr_alert("%s" TORTURE_FLAG | |
2092 | " RCU barrier testing omitted from run.\n", | |
2093 | torture_type); | |
fae4b54f PM |
2094 | return 0; |
2095 | } | |
2096 | atomic_set(&barrier_cbs_count, 0); | |
2097 | atomic_set(&barrier_cbs_invoked, 0); | |
2098 | barrier_cbs_tasks = | |
68a675d4 | 2099 | kcalloc(n_barrier_cbs, sizeof(barrier_cbs_tasks[0]), |
fae4b54f PM |
2100 | GFP_KERNEL); |
2101 | barrier_cbs_wq = | |
68a675d4 | 2102 | kcalloc(n_barrier_cbs, sizeof(barrier_cbs_wq[0]), GFP_KERNEL); |
de5e6437 | 2103 | if (barrier_cbs_tasks == NULL || !barrier_cbs_wq) |
fae4b54f PM |
2104 | return -ENOMEM; |
2105 | for (i = 0; i < n_barrier_cbs; i++) { | |
2106 | init_waitqueue_head(&barrier_cbs_wq[i]); | |
47cf29b9 PM |
2107 | ret = torture_create_kthread(rcu_torture_barrier_cbs, |
2108 | (void *)(long)i, | |
2109 | barrier_cbs_tasks[i]); | |
2110 | if (ret) | |
fae4b54f | 2111 | return ret; |
fae4b54f | 2112 | } |
47cf29b9 | 2113 | return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task); |
fae4b54f PM |
2114 | } |
2115 | ||
2116 | /* Clean up after RCU barrier testing. */ | |
2117 | static void rcu_torture_barrier_cleanup(void) | |
2118 | { | |
2119 | int i; | |
2120 | ||
9c029b86 | 2121 | torture_stop_kthread(rcu_torture_barrier, barrier_task); |
fae4b54f | 2122 | if (barrier_cbs_tasks != NULL) { |
9c029b86 PM |
2123 | for (i = 0; i < n_barrier_cbs; i++) |
2124 | torture_stop_kthread(rcu_torture_barrier_cbs, | |
2125 | barrier_cbs_tasks[i]); | |
fae4b54f PM |
2126 | kfree(barrier_cbs_tasks); |
2127 | barrier_cbs_tasks = NULL; | |
2128 | } | |
2129 | if (barrier_cbs_wq != NULL) { | |
2130 | kfree(barrier_cbs_wq); | |
2131 | barrier_cbs_wq = NULL; | |
2132 | } | |
2133 | } | |
2134 | ||
4babd855 JFG |
2135 | static bool rcu_torture_can_boost(void) |
2136 | { | |
2137 | static int boost_warn_once; | |
2138 | int prio; | |
2139 | ||
2140 | if (!(test_boost == 1 && cur_ops->can_boost) && test_boost != 2) | |
2141 | return false; | |
2142 | ||
2143 | prio = rcu_get_gp_kthreads_prio(); | |
2144 | if (!prio) | |
2145 | return false; | |
2146 | ||
2147 | if (prio < 2) { | |
2148 | if (boost_warn_once == 1) | |
2149 | return false; | |
2150 | ||
bf5b6435 | 2151 | pr_alert("%s: WARN: RCU kthread priority too low to test boosting. Skipping RCU boost test. Try passing rcutree.kthread_prio > 1 on the kernel command line.\n", KBUILD_MODNAME); |
4babd855 JFG |
2152 | boost_warn_once = 1; |
2153 | return false; | |
2154 | } | |
2155 | ||
2156 | return true; | |
2157 | } | |
2158 | ||
0ffd374b | 2159 | static enum cpuhp_state rcutor_hp; |
8e8be45e | 2160 | |
a241ec65 PM |
2161 | static void |
2162 | rcu_torture_cleanup(void) | |
2163 | { | |
c116dba6 | 2164 | int firsttime; |
034777d7 | 2165 | int flags = 0; |
aebc8264 | 2166 | unsigned long gp_seq = 0; |
a241ec65 PM |
2167 | int i; |
2168 | ||
d36a7a0d | 2169 | if (torture_cleanup_begin()) { |
343e9099 PM |
2170 | if (cur_ops->cb_barrier != NULL) |
2171 | cur_ops->cb_barrier(); | |
2172 | return; | |
2173 | } | |
b813afae PM |
2174 | if (!cur_ops) { |
2175 | torture_cleanup_end(); | |
2176 | return; | |
2177 | } | |
d84f5203 | 2178 | |
f7a81b12 | 2179 | show_rcu_gp_kthreads(); |
fae4b54f | 2180 | rcu_torture_barrier_cleanup(); |
1b27291b | 2181 | torture_stop_kthread(rcu_torture_fwd_prog, fwd_prog_task); |
9c029b86 | 2182 | torture_stop_kthread(rcu_torture_stall, stall_task); |
9c029b86 | 2183 | torture_stop_kthread(rcu_torture_writer, writer_task); |
a241ec65 | 2184 | |
c8e5b163 | 2185 | if (reader_tasks) { |
9c029b86 PM |
2186 | for (i = 0; i < nrealreaders; i++) |
2187 | torture_stop_kthread(rcu_torture_reader, | |
2188 | reader_tasks[i]); | |
a241ec65 | 2189 | kfree(reader_tasks); |
a241ec65 PM |
2190 | } |
2191 | rcu_torture_current = NULL; | |
2192 | ||
c8e5b163 | 2193 | if (fakewriter_tasks) { |
b772e1dd | 2194 | for (i = 0; i < nfakewriters; i++) { |
9c029b86 PM |
2195 | torture_stop_kthread(rcu_torture_fakewriter, |
2196 | fakewriter_tasks[i]); | |
b772e1dd JT |
2197 | } |
2198 | kfree(fakewriter_tasks); | |
2199 | fakewriter_tasks = NULL; | |
2200 | } | |
2201 | ||
aebc8264 PM |
2202 | rcutorture_get_gp_data(cur_ops->ttype, &flags, &gp_seq); |
2203 | srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, &flags, &gp_seq); | |
2204 | pr_alert("%s: End-test grace-period state: g%lu f%#x\n", | |
2205 | cur_ops->name, gp_seq, flags); | |
9c029b86 PM |
2206 | torture_stop_kthread(rcu_torture_stats, stats_task); |
2207 | torture_stop_kthread(rcu_torture_fqs, fqs_task); | |
4babd855 | 2208 | if (rcu_torture_can_boost()) |
0ffd374b | 2209 | cpuhp_remove_state(rcutor_hp); |
bf66f18e | 2210 | |
ca1d51ed | 2211 | /* |
62a1a945 | 2212 | * Wait for all RCU callbacks to fire, then do torture-type-specific |
ca1d51ed PM |
2213 | * cleanup operations. |
2214 | */ | |
2326974d PM |
2215 | if (cur_ops->cb_barrier != NULL) |
2216 | cur_ops->cb_barrier(); | |
ca1d51ed PM |
2217 | if (cur_ops->cleanup != NULL) |
2218 | cur_ops->cleanup(); | |
a241ec65 | 2219 | |
a241ec65 | 2220 | rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ |
72e9bb54 | 2221 | |
c116dba6 PM |
2222 | if (err_segs_recorded) { |
2223 | pr_alert("Failure/close-call rcutorture reader segments:\n"); | |
2224 | if (rt_read_nsegs == 0) | |
2225 | pr_alert("\t: No segments recorded!!!\n"); | |
2226 | firsttime = 1; | |
2227 | for (i = 0; i < rt_read_nsegs; i++) { | |
2228 | pr_alert("\t%d: %#x ", i, err_segs[i].rt_readstate); | |
2229 | if (err_segs[i].rt_delay_jiffies != 0) { | |
2230 | pr_cont("%s%ldjiffies", firsttime ? "" : "+", | |
2231 | err_segs[i].rt_delay_jiffies); | |
2232 | firsttime = 0; | |
2233 | } | |
2234 | if (err_segs[i].rt_delay_ms != 0) { | |
2235 | pr_cont("%s%ldms", firsttime ? "" : "+", | |
2236 | err_segs[i].rt_delay_ms); | |
2237 | firsttime = 0; | |
2238 | } | |
2239 | if (err_segs[i].rt_delay_us != 0) { | |
2240 | pr_cont("%s%ldus", firsttime ? "" : "+", | |
2241 | err_segs[i].rt_delay_us); | |
2242 | firsttime = 0; | |
2243 | } | |
2244 | pr_cont("%s\n", | |
2245 | err_segs[i].rt_preempted ? "preempted" : ""); | |
2246 | ||
2247 | } | |
2248 | } | |
fae4b54f | 2249 | if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error) |
8e8be45e | 2250 | rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE"); |
2e9e8081 | 2251 | else if (torture_onoff_failures()) |
091541bb PM |
2252 | rcu_torture_print_module_parms(cur_ops, |
2253 | "End of test: RCU_HOTPLUG"); | |
95c38322 | 2254 | else |
8e8be45e | 2255 | rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS"); |
d36a7a0d | 2256 | torture_cleanup_end(); |
a241ec65 PM |
2257 | } |
2258 | ||
d2818df1 PM |
2259 | #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD |
2260 | static void rcu_torture_leak_cb(struct rcu_head *rhp) | |
2261 | { | |
2262 | } | |
2263 | ||
2264 | static void rcu_torture_err_cb(struct rcu_head *rhp) | |
2265 | { | |
2266 | /* | |
2267 | * This -might- happen due to race conditions, but is unlikely. | |
2268 | * The scenario that leads to this happening is that the | |
2269 | * first of the pair of duplicate callbacks is queued, | |
2270 | * someone else starts a grace period that includes that | |
2271 | * callback, then the second of the pair must wait for the | |
2272 | * next grace period. Unlikely, but can happen. If it | |
2273 | * does happen, the debug-objects subsystem won't have splatted. | |
2274 | */ | |
e0d31a34 | 2275 | pr_alert("%s: duplicated callback was invoked.\n", KBUILD_MODNAME); |
d2818df1 PM |
2276 | } |
2277 | #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ | |
2278 | ||
2279 | /* | |
2280 | * Verify that double-free causes debug-objects to complain, but only | |
2281 | * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test | |
2282 | * cannot be carried out. | |
2283 | */ | |
2284 | static void rcu_test_debug_objects(void) | |
2285 | { | |
2286 | #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD | |
2287 | struct rcu_head rh1; | |
2288 | struct rcu_head rh2; | |
2289 | ||
2290 | init_rcu_head_on_stack(&rh1); | |
2291 | init_rcu_head_on_stack(&rh2); | |
e0d31a34 | 2292 | pr_alert("%s: WARN: Duplicate call_rcu() test starting.\n", KBUILD_MODNAME); |
d2818df1 PM |
2293 | |
2294 | /* Try to queue the rh2 pair of callbacks for the same grace period. */ | |
2295 | preempt_disable(); /* Prevent preemption from interrupting test. */ | |
2296 | rcu_read_lock(); /* Make it impossible to finish a grace period. */ | |
2297 | call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */ | |
2298 | local_irq_disable(); /* Make it harder to start a new grace period. */ | |
2299 | call_rcu(&rh2, rcu_torture_leak_cb); | |
2300 | call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */ | |
2301 | local_irq_enable(); | |
2302 | rcu_read_unlock(); | |
2303 | preempt_enable(); | |
2304 | ||
2305 | /* Wait for them all to get done so we can safely return. */ | |
2306 | rcu_barrier(); | |
e0d31a34 | 2307 | pr_alert("%s: WARN: Duplicate call_rcu() test complete.\n", KBUILD_MODNAME); |
d2818df1 PM |
2308 | destroy_rcu_head_on_stack(&rh1); |
2309 | destroy_rcu_head_on_stack(&rh2); | |
2310 | #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ | |
e0d31a34 | 2311 | pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n", KBUILD_MODNAME); |
d2818df1 PM |
2312 | #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ |
2313 | } | |
2314 | ||
3a6cb58f PM |
2315 | static void rcutorture_sync(void) |
2316 | { | |
2317 | static unsigned long n; | |
2318 | ||
2319 | if (cur_ops->sync && !(++n & 0xfff)) | |
2320 | cur_ops->sync(); | |
2321 | } | |
2322 | ||
6f8bc500 | 2323 | static int __init |
a241ec65 PM |
2324 | rcu_torture_init(void) |
2325 | { | |
c04dd09b | 2326 | long i; |
a241ec65 PM |
2327 | int cpu; |
2328 | int firsterr = 0; | |
2ec1f2d9 | 2329 | static struct rcu_torture_ops *torture_ops[] = { |
c770c82a | 2330 | &rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops, |
c682db55 | 2331 | &busted_srcud_ops, &tasks_ops, &trivial_ops, |
2ec1f2d9 | 2332 | }; |
a241ec65 | 2333 | |
a2f2577d | 2334 | if (!torture_init_begin(torture_type, verbose)) |
5228084e | 2335 | return -EBUSY; |
343e9099 | 2336 | |
a241ec65 | 2337 | /* Process args and tell the world that the torturer is on the job. */ |
ade5fb81 | 2338 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { |
72e9bb54 | 2339 | cur_ops = torture_ops[i]; |
ade5fb81 | 2340 | if (strcmp(torture_type, cur_ops->name) == 0) |
72e9bb54 | 2341 | break; |
72e9bb54 | 2342 | } |
ade5fb81 | 2343 | if (i == ARRAY_SIZE(torture_ops)) { |
2caa1e44 PM |
2344 | pr_alert("rcu-torture: invalid torture type: \"%s\"\n", |
2345 | torture_type); | |
2346 | pr_alert("rcu-torture types:"); | |
cf886c44 | 2347 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) |
a7538352 JP |
2348 | pr_cont(" %s", torture_ops[i]->name); |
2349 | pr_cont("\n"); | |
e746b558 | 2350 | WARN_ON(!IS_MODULE(CONFIG_RCU_TORTURE_TEST)); |
889d487a | 2351 | firsterr = -EINVAL; |
b813afae | 2352 | cur_ops = NULL; |
889d487a | 2353 | goto unwind; |
72e9bb54 | 2354 | } |
bf66f18e | 2355 | if (cur_ops->fqs == NULL && fqs_duration != 0) { |
2caa1e44 | 2356 | pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n"); |
bf66f18e PM |
2357 | fqs_duration = 0; |
2358 | } | |
c8e5b163 | 2359 | if (cur_ops->init) |
889d487a | 2360 | cur_ops->init(); |
72e9bb54 | 2361 | |
64e4b43a | 2362 | if (nreaders >= 0) { |
a241ec65 | 2363 | nrealreaders = nreaders; |
64e4b43a | 2364 | } else { |
3838cc18 | 2365 | nrealreaders = num_online_cpus() - 2 - nreaders; |
64e4b43a PM |
2366 | if (nrealreaders <= 0) |
2367 | nrealreaders = 1; | |
2368 | } | |
8e8be45e | 2369 | rcu_torture_print_module_parms(cur_ops, "Start of test"); |
a241ec65 PM |
2370 | |
2371 | /* Set up the freelist. */ | |
2372 | ||
2373 | INIT_LIST_HEAD(&rcu_torture_freelist); | |
788e770e | 2374 | for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) { |
996417d2 | 2375 | rcu_tortures[i].rtort_mbtest = 0; |
a241ec65 PM |
2376 | list_add_tail(&rcu_tortures[i].rtort_free, |
2377 | &rcu_torture_freelist); | |
2378 | } | |
2379 | ||
2380 | /* Initialize the statistics so that each run gets its own numbers. */ | |
2381 | ||
2382 | rcu_torture_current = NULL; | |
2383 | rcu_torture_current_version = 0; | |
2384 | atomic_set(&n_rcu_torture_alloc, 0); | |
2385 | atomic_set(&n_rcu_torture_alloc_fail, 0); | |
2386 | atomic_set(&n_rcu_torture_free, 0); | |
996417d2 PM |
2387 | atomic_set(&n_rcu_torture_mberror, 0); |
2388 | atomic_set(&n_rcu_torture_error, 0); | |
fae4b54f | 2389 | n_rcu_torture_barrier_error = 0; |
8e8be45e PM |
2390 | n_rcu_torture_boost_ktrerror = 0; |
2391 | n_rcu_torture_boost_rterror = 0; | |
8e8be45e PM |
2392 | n_rcu_torture_boost_failure = 0; |
2393 | n_rcu_torture_boosts = 0; | |
a241ec65 PM |
2394 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
2395 | atomic_set(&rcu_torture_wcount[i], 0); | |
0a945022 | 2396 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
2397 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
2398 | per_cpu(rcu_torture_count, cpu)[i] = 0; | |
2399 | per_cpu(rcu_torture_batch, cpu)[i] = 0; | |
2400 | } | |
2401 | } | |
c116dba6 PM |
2402 | err_segs_recorded = 0; |
2403 | rt_read_nsegs = 0; | |
a241ec65 PM |
2404 | |
2405 | /* Start up the kthreads. */ | |
2406 | ||
47cf29b9 PM |
2407 | firsterr = torture_create_kthread(rcu_torture_writer, NULL, |
2408 | writer_task); | |
2409 | if (firsterr) | |
a241ec65 | 2410 | goto unwind; |
4444d852 | 2411 | if (nfakewriters > 0) { |
68a675d4 | 2412 | fakewriter_tasks = kcalloc(nfakewriters, |
4444d852 PM |
2413 | sizeof(fakewriter_tasks[0]), |
2414 | GFP_KERNEL); | |
2415 | if (fakewriter_tasks == NULL) { | |
2416 | VERBOSE_TOROUT_ERRSTRING("out of memory"); | |
2417 | firsterr = -ENOMEM; | |
2418 | goto unwind; | |
2419 | } | |
b772e1dd JT |
2420 | } |
2421 | for (i = 0; i < nfakewriters; i++) { | |
47cf29b9 PM |
2422 | firsterr = torture_create_kthread(rcu_torture_fakewriter, |
2423 | NULL, fakewriter_tasks[i]); | |
2424 | if (firsterr) | |
b772e1dd | 2425 | goto unwind; |
b772e1dd | 2426 | } |
68a675d4 | 2427 | reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]), |
a241ec65 PM |
2428 | GFP_KERNEL); |
2429 | if (reader_tasks == NULL) { | |
5ccf60f2 | 2430 | VERBOSE_TOROUT_ERRSTRING("out of memory"); |
a241ec65 PM |
2431 | firsterr = -ENOMEM; |
2432 | goto unwind; | |
2433 | } | |
2434 | for (i = 0; i < nrealreaders; i++) { | |
c04dd09b | 2435 | firsterr = torture_create_kthread(rcu_torture_reader, (void *)i, |
47cf29b9 PM |
2436 | reader_tasks[i]); |
2437 | if (firsterr) | |
a241ec65 | 2438 | goto unwind; |
a241ec65 PM |
2439 | } |
2440 | if (stat_interval > 0) { | |
47cf29b9 PM |
2441 | firsterr = torture_create_kthread(rcu_torture_stats, NULL, |
2442 | stats_task); | |
2443 | if (firsterr) | |
a241ec65 | 2444 | goto unwind; |
a241ec65 | 2445 | } |
e8e255f7 | 2446 | if (test_no_idle_hz && shuffle_interval > 0) { |
3808dc9f PM |
2447 | firsterr = torture_shuffle_init(shuffle_interval * HZ); |
2448 | if (firsterr) | |
d84f5203 | 2449 | goto unwind; |
d84f5203 | 2450 | } |
d120f65f PM |
2451 | if (stutter < 0) |
2452 | stutter = 0; | |
2453 | if (stutter) { | |
ff3bf92d PM |
2454 | int t; |
2455 | ||
2456 | t = cur_ops->stall_dur ? cur_ops->stall_dur() : stutter * HZ; | |
2457 | firsterr = torture_stutter_init(stutter * HZ, t); | |
628edaa5 | 2458 | if (firsterr) |
d120f65f | 2459 | goto unwind; |
d120f65f | 2460 | } |
bf66f18e PM |
2461 | if (fqs_duration < 0) |
2462 | fqs_duration = 0; | |
2463 | if (fqs_duration) { | |
628edaa5 | 2464 | /* Create the fqs thread */ |
d0d0606e PM |
2465 | firsterr = torture_create_kthread(rcu_torture_fqs, NULL, |
2466 | fqs_task); | |
47cf29b9 | 2467 | if (firsterr) |
bf66f18e | 2468 | goto unwind; |
bf66f18e | 2469 | } |
8e8be45e PM |
2470 | if (test_boost_interval < 1) |
2471 | test_boost_interval = 1; | |
2472 | if (test_boost_duration < 2) | |
2473 | test_boost_duration = 2; | |
4babd855 | 2474 | if (rcu_torture_can_boost()) { |
8e8be45e PM |
2475 | |
2476 | boost_starttime = jiffies + test_boost_interval * HZ; | |
0ffd374b SAS |
2477 | |
2478 | firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE", | |
2479 | rcutorture_booster_init, | |
2480 | rcutorture_booster_cleanup); | |
2481 | if (firsterr < 0) | |
2482 | goto unwind; | |
2483 | rcutor_hp = firsterr; | |
8e8be45e | 2484 | } |
60013d5d | 2485 | shutdown_jiffies = jiffies + shutdown_secs * HZ; |
01025ebc PM |
2486 | firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup); |
2487 | if (firsterr) | |
37e377d2 | 2488 | goto unwind; |
3a6cb58f PM |
2489 | firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval, |
2490 | rcutorture_sync); | |
01025ebc | 2491 | if (firsterr) |
37e377d2 | 2492 | goto unwind; |
01025ebc | 2493 | firsterr = rcu_torture_stall_init(); |
1b27291b PM |
2494 | if (firsterr) |
2495 | goto unwind; | |
2496 | firsterr = rcu_torture_fwd_prog_init(); | |
01025ebc | 2497 | if (firsterr) |
37e377d2 | 2498 | goto unwind; |
01025ebc PM |
2499 | firsterr = rcu_torture_barrier_init(); |
2500 | if (firsterr) | |
fae4b54f | 2501 | goto unwind; |
d2818df1 PM |
2502 | if (object_debug) |
2503 | rcu_test_debug_objects(); | |
b5daa8f3 | 2504 | torture_init_end(); |
a241ec65 PM |
2505 | return 0; |
2506 | ||
2507 | unwind: | |
b5daa8f3 | 2508 | torture_init_end(); |
a241ec65 PM |
2509 | rcu_torture_cleanup(); |
2510 | return firsterr; | |
2511 | } | |
2512 | ||
2513 | module_init(rcu_torture_init); | |
2514 | module_exit(rcu_torture_cleanup); |