source: libcfa/src/concurrency/ready_queue.cfa@ 85a2c3f

ADT ast-experimental enum forall-pointer-decay pthread-emulation qualifiedEnum
Last change on this file since 85a2c3f was 46bbcaf, checked in by Thierry Delisle <tdelisle@…>, 4 years ago

Fix race condition in verify
  • Property mode set to 100644
File size: 40.1 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2019 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// ready_queue.cfa --
8//
9// Author : Thierry Delisle
10// Created On : Mon Nov dd 16:29:18 2019
11// Last Modified By :
12// Last Modified On :
13// Update Count :
14//
15
16#define __cforall_thread__
17#define _GNU_SOURCE
18
19// #define __CFA_DEBUG_PRINT_READY_QUEUE__
20
21
22// #define USE_RELAXED_FIFO
23// #define USE_WORK_STEALING
24// #define USE_CPU_WORK_STEALING
25#define USE_AWARE_STEALING
26
27#include "bits/defs.hfa"
28#include "device/cpu.hfa"
29#include "kernel_private.hfa"
30
31#include "stdlib.hfa"
32#include "limits.hfa"
33#include "math.hfa"
34
35#include <errno.h>
36#include <unistd.h>
37
38extern "C" {
39 #include <sys/syscall.h> // __NR_xxx
40}
41
42#include "ready_subqueue.hfa"
43
44static const size_t cache_line_size = 64;
45
46#if !defined(__CFA_NO_STATISTICS__)
47 #define __STATS(...) __VA_ARGS__
48#else
49 #define __STATS(...)
50#endif
51
52// No overriden function, no environment variable, no define
53// fall back to a magic number
54#ifndef __CFA_MAX_PROCESSORS__
55 #define __CFA_MAX_PROCESSORS__ 1024
56#endif
57
58#if defined(USE_AWARE_STEALING)
59 #define READYQ_SHARD_FACTOR 2
60 #define SEQUENTIAL_SHARD 2
61#elif defined(USE_CPU_WORK_STEALING)
62 #define READYQ_SHARD_FACTOR 2
63#elif defined(USE_RELAXED_FIFO)
64 #define BIAS 4
65 #define READYQ_SHARD_FACTOR 4
66 #define SEQUENTIAL_SHARD 1
67#elif defined(USE_WORK_STEALING)
68 #define READYQ_SHARD_FACTOR 2
69 #define SEQUENTIAL_SHARD 2
70#else
71 #error no scheduling strategy selected
72#endif
73
74static inline struct thread$ * try_pop(struct cluster * cltr, unsigned w __STATS(, __stats_readyQ_pop_t & stats));
75static inline struct thread$ * try_pop(struct cluster * cltr, unsigned i, unsigned j __STATS(, __stats_readyQ_pop_t & stats));
76static inline struct thread$ * search(struct cluster * cltr);
77static inline [unsigned, bool] idx_from_r(unsigned r, unsigned preferred);
78
79
80// returns the maximum number of processors the RWLock support
81__attribute__((weak)) unsigned __max_processors() {
82 const char * max_cores_s = getenv("CFA_MAX_PROCESSORS");
83 if(!max_cores_s) {
84 __cfadbg_print_nolock(ready_queue, "No CFA_MAX_PROCESSORS in ENV\n");
85 return __CFA_MAX_PROCESSORS__;
86 }
87
88 char * endptr = 0p;
89 long int max_cores_l = strtol(max_cores_s, &endptr, 10);
90 if(max_cores_l < 1 || max_cores_l > 65535) {
91 __cfadbg_print_nolock(ready_queue, "CFA_MAX_PROCESSORS out of range : %ld\n", max_cores_l);
92 return __CFA_MAX_PROCESSORS__;
93 }
94 if('\0' != *endptr) {
95 __cfadbg_print_nolock(ready_queue, "CFA_MAX_PROCESSORS not a decimal number : %s\n", max_cores_s);
96 return __CFA_MAX_PROCESSORS__;
97 }
98
99 return max_cores_l;
100}
101
102#if defined(CFA_HAVE_LINUX_LIBRSEQ)
103 // No forward declaration needed
104 #define __kernel_rseq_register rseq_register_current_thread
105 #define __kernel_rseq_unregister rseq_unregister_current_thread
106#elif defined(CFA_HAVE_LINUX_RSEQ_H)
107 static void __kernel_raw_rseq_register (void);
108 static void __kernel_raw_rseq_unregister(void);
109
110 #define __kernel_rseq_register __kernel_raw_rseq_register
111 #define __kernel_rseq_unregister __kernel_raw_rseq_unregister
112#else
113 // No forward declaration needed
114 // No initialization needed
115 static inline void noop(void) {}
116
117 #define __kernel_rseq_register noop
118 #define __kernel_rseq_unregister noop
119#endif
120
121//=======================================================================
122// Cluster wide reader-writer lock
123//=======================================================================
124void ?{}(__scheduler_RWLock_t & this) {
125 this.max = __max_processors();
126 this.alloc = 0;
127 this.ready = 0;
128 this.data = alloc(this.max);
129 this.write_lock = false;
130
131 /*paranoid*/ verify(__atomic_is_lock_free(sizeof(this.alloc), &this.alloc));
132 /*paranoid*/ verify(__atomic_is_lock_free(sizeof(this.ready), &this.ready));
133
134}
135void ^?{}(__scheduler_RWLock_t & this) {
136 free(this.data);
137}
138
139
140//=======================================================================
141// Lock-Free registering/unregistering of threads
142unsigned register_proc_id( void ) with(*__scheduler_lock) {
143 __kernel_rseq_register();
144
145 bool * handle = (bool *)&kernelTLS().sched_lock;
146
147 // Step - 1 : check if there is already space in the data
148 uint_fast32_t s = ready;
149
150 // Check among all the ready
151 for(uint_fast32_t i = 0; i < s; i++) {
152 bool * volatile * cell = (bool * volatile *)&data[i]; // Cforall is bugged and the double volatiles causes problems
153 /* paranoid */ verify( handle != *cell );
154
155 bool * null = 0p; // Re-write every loop since compare thrashes it
156 if( __atomic_load_n(cell, (int)__ATOMIC_RELAXED) == null
157 && __atomic_compare_exchange_n( cell, &null, handle, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) {
158 /* paranoid */ verify(i < ready);
159 /* paranoid */ verify( (kernelTLS().sched_id = i, true) );
160 return i;
161 }
162 }
163
164 if(max <= alloc) abort("Trying to create more than %ud processors", __scheduler_lock->max);
165
166 // Step - 2 : F&A to get a new spot in the array.
167 uint_fast32_t n = __atomic_fetch_add(&alloc, 1, __ATOMIC_SEQ_CST);
168 if(max <= n) abort("Trying to create more than %ud processors", __scheduler_lock->max);
169
170 // Step - 3 : Mark space as used and then publish it.
171 data[n] = handle;
172 while() {
173 unsigned copy = n;
174 if( __atomic_load_n(&ready, __ATOMIC_RELAXED) == n
175 && __atomic_compare_exchange_n(&ready, &copy, n + 1, true, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST))
176 break;
177 Pause();
178 }
179
180 // Return new spot.
181 /* paranoid */ verify(n < ready);
182 /* paranoid */ verify( (kernelTLS().sched_id = n, true) );
183 return n;
184}
185
186void unregister_proc_id( unsigned id ) with(*__scheduler_lock) {
187 /* paranoid */ verify(id < ready);
188 /* paranoid */ verify(id == kernelTLS().sched_id);
189 /* paranoid */ verify(data[id] == &kernelTLS().sched_lock);
190
191 bool * volatile * cell = (bool * volatile *)&data[id]; // Cforall is bugged and the double volatiles causes problems
192
193 __atomic_store_n(cell, 0p, __ATOMIC_RELEASE);
194
195 __kernel_rseq_unregister();
196}
197
198//-----------------------------------------------------------------------
199// Writer side : acquire when changing the ready queue, e.g. adding more
200// queues or removing them.
201uint_fast32_t ready_mutate_lock( void ) with(*__scheduler_lock) {
202 /* paranoid */ verify( ! __preemption_enabled() );
203
204 // Step 1 : lock global lock
205 // It is needed to avoid processors that register mid Critical-Section
206 // to simply lock their own lock and enter.
207 __atomic_acquire( &write_lock );
208
209 // Make sure we won't deadlock ourself
210 // Checking before acquiring the writer lock isn't safe
211 // because someone else could have locked us.
212 /* paranoid */ verify( ! kernelTLS().sched_lock );
213
214 // Step 2 : lock per-proc lock
215 // Processors that are currently being registered aren't counted
216 // but can't be in read_lock or in the critical section.
217 // All other processors are counted
218 uint_fast32_t s = ready;
219 for(uint_fast32_t i = 0; i < s; i++) {
220 volatile bool * llock = data[i];
221 if(llock) __atomic_acquire( llock );
222 }
223
224 /* paranoid */ verify( ! __preemption_enabled() );
225 return s;
226}
227
228void ready_mutate_unlock( uint_fast32_t last_s ) with(*__scheduler_lock) {
229 /* paranoid */ verify( ! __preemption_enabled() );
230
231 // Step 1 : release local locks
232 // This must be done while the global lock is held to avoid
233 // threads that where created mid critical section
234 // to race to lock their local locks and have the writer
235 // immidiately unlock them
236 // Alternative solution : return s in write_lock and pass it to write_unlock
237 for(uint_fast32_t i = 0; i < last_s; i++) {
238 volatile bool * llock = data[i];
239 if(llock) __atomic_store_n(llock, (bool)false, __ATOMIC_RELEASE);
240 }
241
242 // Step 2 : release global lock
243 /*paranoid*/ assert(true == write_lock);
244 __atomic_store_n(&write_lock, (bool)false, __ATOMIC_RELEASE);
245
246 /* paranoid */ verify( ! __preemption_enabled() );
247}
248
249//=======================================================================
250// caches handling
251
252struct __attribute__((aligned(128))) __ready_queue_caches_t {
253 // Count States:
254 // - 0 : No one is looking after this cache
255 // - 1 : No one is looking after this cache, BUT it's not empty
256 // - 2+ : At least one processor is looking after this cache
257 volatile unsigned count;
258};
259
260void ?{}(__ready_queue_caches_t & this) { this.count = 0; }
261void ^?{}(__ready_queue_caches_t & this) {}
262
263static inline void depart(__ready_queue_caches_t & cache) {
264 /* paranoid */ verify( cache.count > 1);
265 __atomic_fetch_add(&cache.count, -1, __ATOMIC_SEQ_CST);
266 /* paranoid */ verify( cache.count != 0);
267 /* paranoid */ verify( cache.count < 65536 ); // This verify assumes no cluster will have more than 65000 kernel threads mapped to a single cache, which could be correct but is super weird.
268}
269
270static inline void arrive(__ready_queue_caches_t & cache) {
271 // for() {
272 // unsigned expected = cache.count;
273 // unsigned desired = 0 == expected ? 2 : expected + 1;
274 // }
275}
276
277//=======================================================================
278// Cforall Ready Queue used for scheduling
279//=======================================================================
280unsigned long long moving_average(unsigned long long currtsc, unsigned long long instsc, unsigned long long old_avg) {
281 /* paranoid */ verifyf( currtsc < 45000000000000000, "Suspiciously large current time: %'llu (%llx)\n", currtsc, currtsc );
282 /* paranoid */ verifyf( instsc < 45000000000000000, "Suspiciously large insert time: %'llu (%llx)\n", instsc, instsc );
283 /* paranoid */ verifyf( old_avg < 15000000000000, "Suspiciously large previous average: %'llu (%llx)\n", old_avg, old_avg );
284
285 const unsigned long long new_val = currtsc > instsc ? currtsc - instsc : 0;
286 const unsigned long long total_weight = 16;
287 const unsigned long long new_weight = 4;
288 const unsigned long long old_weight = total_weight - new_weight;
289 const unsigned long long ret = ((new_weight * new_val) + (old_weight * old_avg)) / total_weight;
290 return ret;
291}
292
293void ?{}(__ready_queue_t & this) with (this) {
294 #if defined(USE_CPU_WORK_STEALING)
295 lanes.count = cpu_info.hthrd_count * READYQ_SHARD_FACTOR;
296 lanes.data = alloc( lanes.count );
297 lanes.tscs = alloc( lanes.count );
298 lanes.help = alloc( cpu_info.hthrd_count );
299
300 for( idx; (size_t)lanes.count ) {
301 (lanes.data[idx]){};
302 lanes.tscs[idx].tv = rdtscl();
303 lanes.tscs[idx].ma = rdtscl();
304 }
305 for( idx; (size_t)cpu_info.hthrd_count ) {
306 lanes.help[idx].src = 0;
307 lanes.help[idx].dst = 0;
308 lanes.help[idx].tri = 0;
309 }
310 #else
311 lanes.data = 0p;
312 lanes.tscs = 0p;
313 lanes.caches = 0p;
314 lanes.help = 0p;
315 lanes.count = 0;
316 #endif
317}
318
319void ^?{}(__ready_queue_t & this) with (this) {
320 #if !defined(USE_CPU_WORK_STEALING)
321 verify( SEQUENTIAL_SHARD == lanes.count );
322 #endif
323
324 free(lanes.data);
325 free(lanes.tscs);
326 free(lanes.caches);
327 free(lanes.help);
328}
329
330//-----------------------------------------------------------------------
331#if defined(USE_AWARE_STEALING)
332 __attribute__((hot)) void push(struct cluster * cltr, struct thread$ * thrd, unpark_hint hint) with (cltr->ready_queue) {
333 processor * const proc = kernelTLS().this_processor;
334 const bool external = (!proc) || (cltr != proc->cltr);
335 const bool remote = hint == UNPARK_REMOTE;
336
337 unsigned i;
338 if( external || remote ) {
339 // Figure out where thread was last time and make sure it's valid
340 /* paranoid */ verify(thrd->preferred >= 0);
341 if(thrd->preferred * READYQ_SHARD_FACTOR < lanes.count) {
342 /* paranoid */ verify(thrd->preferred * READYQ_SHARD_FACTOR < lanes.count);
343 unsigned start = thrd->preferred * READYQ_SHARD_FACTOR;
344 do {
345 unsigned r = __tls_rand();
346 i = start + (r % READYQ_SHARD_FACTOR);
347 /* paranoid */ verify( i < lanes.count );
348 // If we can't lock it retry
349 } while( !__atomic_try_acquire( &lanes.data[i].lock ) );
350 } else {
351 do {
352 i = __tls_rand() % lanes.count;
353 } while( !__atomic_try_acquire( &lanes.data[i].lock ) );
354 }
355 } else {
356 do {
357 unsigned r = proc->rdq.its++;
358 i = proc->rdq.id + (r % READYQ_SHARD_FACTOR);
359 /* paranoid */ verify( i < lanes.count );
360 // If we can't lock it retry
361 } while( !__atomic_try_acquire( &lanes.data[i].lock ) );
362 }
363
364 // Actually push it
365 push(lanes.data[i], thrd);
366
367 // Unlock and return
368 __atomic_unlock( &lanes.data[i].lock );
369
370 #if !defined(__CFA_NO_STATISTICS__)
371 if(unlikely(external || remote)) __atomic_fetch_add(&cltr->stats->ready.push.extrn.success, 1, __ATOMIC_RELAXED);
372 else __tls_stats()->ready.push.local.success++;
373 #endif
374 }
375
376 static inline unsigned long long calc_cutoff(const unsigned long long ctsc, const processor * proc, __ready_queue_t & rdq) {
377 unsigned start = proc->rdq.id;
378 unsigned long long max = 0;
379 for(i; READYQ_SHARD_FACTOR) {
380 unsigned long long ptsc = ts(rdq.lanes.data[start + i]);
381 if(ptsc != -1ull) {
382 /* paranoid */ verify( start + i < rdq.lanes.count );
383 unsigned long long tsc = moving_average(ctsc, ptsc, rdq.lanes.tscs[start + i].ma);
384 if(tsc > max) max = tsc;
385 }
386 }
387 return (max + 2 * max) / 2;
388 }
389
390 __attribute__((hot)) struct thread$ * pop_fast(struct cluster * cltr) with (cltr->ready_queue) {
391 /* paranoid */ verify( lanes.count > 0 );
392 /* paranoid */ verify( kernelTLS().this_processor );
393 /* paranoid */ verify( kernelTLS().this_processor->rdq.id < lanes.count );
394
395 processor * const proc = kernelTLS().this_processor;
396 unsigned this = proc->rdq.id;
397 /* paranoid */ verify( this < lanes.count );
398 __cfadbg_print_safe(ready_queue, "Kernel : pop from %u\n", this);
399
400 // Figure out the current cpu and make sure it is valid
401 const int cpu = __kernel_getcpu();
402 /* paranoid */ verify(cpu >= 0);
403 /* paranoid */ verify(cpu < cpu_info.hthrd_count);
404 unsigned this_cache = cpu_info.llc_map[cpu].cache;
405
406 // Super important: don't write the same value over and over again
407 // We want to maximise our chances that his particular values stays in cache
408 if(lanes.caches[this / READYQ_SHARD_FACTOR].id != this_cache)
409 __atomic_store_n(&lanes.caches[this / READYQ_SHARD_FACTOR].id, this_cache, __ATOMIC_RELAXED);
410
411 const unsigned long long ctsc = rdtscl();
412
413 if(proc->rdq.target == MAX) {
414 uint64_t chaos = __tls_rand();
415 unsigned ext = chaos & 0xff;
416 unsigned other = (chaos >> 8) % (lanes.count);
417
418 if(ext < 3 || __atomic_load_n(&lanes.caches[other / READYQ_SHARD_FACTOR].id, __ATOMIC_RELAXED) == this_cache) {
419 proc->rdq.target = other;
420 }
421 }
422 else {
423 const unsigned target = proc->rdq.target;
424 __cfadbg_print_safe(ready_queue, "Kernel : %u considering helping %u, tcsc %llu\n", this, target, lanes.tscs[target].tv);
425 /* paranoid */ verify( lanes.tscs[target].tv != MAX );
426 if(target < lanes.count) {
427 const unsigned long long cutoff = calc_cutoff(ctsc, proc, cltr->ready_queue);
428 const unsigned long long age = moving_average(ctsc, lanes.tscs[target].tv, lanes.tscs[target].ma);
429 __cfadbg_print_safe(ready_queue, "Kernel : Help attempt on %u from %u, age %'llu vs cutoff %'llu, %s\n", target, this, age, cutoff, age > cutoff ? "yes" : "no");
430 if(age > cutoff) {
431 thread$ * t = try_pop(cltr, target __STATS(, __tls_stats()->ready.pop.help));
432 if(t) return t;
433 }
434 }
435 proc->rdq.target = MAX;
436 }
437
438 for(READYQ_SHARD_FACTOR) {
439 unsigned i = this + (proc->rdq.itr++ % READYQ_SHARD_FACTOR);
440 if(thread$ * t = try_pop(cltr, i __STATS(, __tls_stats()->ready.pop.local))) return t;
441 }
442
443 // All lanes where empty return 0p
444 return 0p;
445
446 }
447 __attribute__((hot)) struct thread$ * pop_slow(struct cluster * cltr) with (cltr->ready_queue) {
448 unsigned i = __tls_rand() % lanes.count;
449 return try_pop(cltr, i __STATS(, __tls_stats()->ready.pop.steal));
450 }
451 __attribute__((hot)) struct thread$ * pop_search(struct cluster * cltr) {
452 return search(cltr);
453 }
454#endif
455#if defined(USE_CPU_WORK_STEALING)
456 __attribute__((hot)) void push(struct cluster * cltr, struct thread$ * thrd, unpark_hint hint) with (cltr->ready_queue) {
457 __cfadbg_print_safe(ready_queue, "Kernel : Pushing %p on cluster %p\n", thrd, cltr);
458
459 processor * const proc = kernelTLS().this_processor;
460 const bool external = (!proc) || (cltr != proc->cltr);
461
462 // Figure out the current cpu and make sure it is valid
463 const int cpu = __kernel_getcpu();
464 /* paranoid */ verify(cpu >= 0);
465 /* paranoid */ verify(cpu < cpu_info.hthrd_count);
466 /* paranoid */ verify(cpu * READYQ_SHARD_FACTOR < lanes.count);
467
468 // Figure out where thread was last time and make sure it's
469 /* paranoid */ verify(thrd->preferred >= 0);
470 /* paranoid */ verify(thrd->preferred < cpu_info.hthrd_count);
471 /* paranoid */ verify(thrd->preferred * READYQ_SHARD_FACTOR < lanes.count);
472 const int prf = thrd->preferred * READYQ_SHARD_FACTOR;
473
474 const cpu_map_entry_t & map;
475 choose(hint) {
476 case UNPARK_LOCAL : &map = &cpu_info.llc_map[cpu];
477 case UNPARK_REMOTE: &map = &cpu_info.llc_map[prf];
478 }
479 /* paranoid */ verify(map.start * READYQ_SHARD_FACTOR < lanes.count);
480 /* paranoid */ verify(map.self * READYQ_SHARD_FACTOR < lanes.count);
481 /* paranoid */ verifyf((map.start + map.count) * READYQ_SHARD_FACTOR <= lanes.count, "have %zu lanes but map can go up to %u", lanes.count, (map.start + map.count) * READYQ_SHARD_FACTOR);
482
483 const int start = map.self * READYQ_SHARD_FACTOR;
484 unsigned i;
485 do {
486 unsigned r;
487 if(unlikely(external)) { r = __tls_rand(); }
488 else { r = proc->rdq.its++; }
489 choose(hint) {
490 case UNPARK_LOCAL : i = start + (r % READYQ_SHARD_FACTOR);
491 case UNPARK_REMOTE: i = prf + (r % READYQ_SHARD_FACTOR);
492 }
493 // If we can't lock it retry
494 } while( !__atomic_try_acquire( &lanes.data[i].lock ) );
495
496 // Actually push it
497 push(lanes.data[i], thrd);
498
499 // Unlock and return
500 __atomic_unlock( &lanes.data[i].lock );
501
502 #if !defined(__CFA_NO_STATISTICS__)
503 if(unlikely(external)) __atomic_fetch_add(&cltr->stats->ready.push.extrn.success, 1, __ATOMIC_RELAXED);
504 else __tls_stats()->ready.push.local.success++;
505 #endif
506
507 __cfadbg_print_safe(ready_queue, "Kernel : Pushed %p on cluster %p (idx: %u, mask %llu, first %d)\n", thrd, cltr, i, used.mask[0], lane_first);
508
509 }
510
511 // Pop from the ready queue from a given cluster
512 __attribute__((hot)) thread$ * pop_fast(struct cluster * cltr) with (cltr->ready_queue) {
513 /* paranoid */ verify( lanes.count > 0 );
514 /* paranoid */ verify( kernelTLS().this_processor );
515
516 processor * const proc = kernelTLS().this_processor;
517 const int cpu = __kernel_getcpu();
518 /* paranoid */ verify(cpu >= 0);
519 /* paranoid */ verify(cpu < cpu_info.hthrd_count);
520 /* paranoid */ verify(cpu * READYQ_SHARD_FACTOR < lanes.count);
521
522 const cpu_map_entry_t & map = cpu_info.llc_map[cpu];
523 /* paranoid */ verify(map.start * READYQ_SHARD_FACTOR < lanes.count);
524 /* paranoid */ verify(map.self * READYQ_SHARD_FACTOR < lanes.count);
525 /* paranoid */ verifyf((map.start + map.count) * READYQ_SHARD_FACTOR <= lanes.count, "have %zu lanes but map can go up to %u", lanes.count, (map.start + map.count) * READYQ_SHARD_FACTOR);
526
527 const int start = map.self * READYQ_SHARD_FACTOR;
528 const unsigned long long ctsc = rdtscl();
529
530 // Did we already have a help target
531 if(proc->rdq.target == MAX) {
532 unsigned long long max = 0;
533 for(i; READYQ_SHARD_FACTOR) {
534 unsigned long long tsc = moving_average(ctsc, ts(lanes.data[start + i]), lanes.tscs[start + i].ma);
535 if(tsc > max) max = tsc;
536 }
537 // proc->rdq.cutoff = (max + 2 * max) / 2;
538 /* paranoid */ verify(lanes.count < 65536); // The following code assumes max 65536 cores.
539 /* paranoid */ verify(map.count < 65536); // The following code assumes max 65536 cores.
540
541 if(0 == (__tls_rand() % 100)) {
542 proc->rdq.target = __tls_rand() % lanes.count;
543 } else {
544 unsigned cpu_chaos = map.start + (__tls_rand() % map.count);
545 proc->rdq.target = (cpu_chaos * READYQ_SHARD_FACTOR) + (__tls_rand() % READYQ_SHARD_FACTOR);
546 /* paranoid */ verify(proc->rdq.target >= (map.start * READYQ_SHARD_FACTOR));
547 /* paranoid */ verify(proc->rdq.target < ((map.start + map.count) * READYQ_SHARD_FACTOR));
548 }
549
550 /* paranoid */ verify(proc->rdq.target != MAX);
551 }
552 else {
553 unsigned long long max = 0;
554 for(i; READYQ_SHARD_FACTOR) {
555 unsigned long long tsc = moving_average(ctsc, ts(lanes.data[start + i]), lanes.tscs[start + i].ma);
556 if(tsc > max) max = tsc;
557 }
558 const unsigned long long cutoff = (max + 2 * max) / 2;
559 {
560 unsigned target = proc->rdq.target;
561 proc->rdq.target = MAX;
562 lanes.help[target / READYQ_SHARD_FACTOR].tri++;
563 if(moving_average(ctsc, lanes.tscs[target].tv, lanes.tscs[target].ma) > cutoff) {
564 thread$ * t = try_pop(cltr, target __STATS(, __tls_stats()->ready.pop.help));
565 proc->rdq.last = target;
566 if(t) return t;
567 }
568 proc->rdq.target = MAX;
569 }
570
571 unsigned last = proc->rdq.last;
572 if(last != MAX && moving_average(ctsc, lanes.tscs[last].tv, lanes.tscs[last].ma) > cutoff) {
573 thread$ * t = try_pop(cltr, last __STATS(, __tls_stats()->ready.pop.help));
574 if(t) return t;
575 }
576 else {
577 proc->rdq.last = MAX;
578 }
579 }
580
581 for(READYQ_SHARD_FACTOR) {
582 unsigned i = start + (proc->rdq.itr++ % READYQ_SHARD_FACTOR);
583 if(thread$ * t = try_pop(cltr, i __STATS(, __tls_stats()->ready.pop.local))) return t;
584 }
585
586 // All lanes where empty return 0p
587 return 0p;
588 }
589
590 __attribute__((hot)) struct thread$ * pop_slow(struct cluster * cltr) with (cltr->ready_queue) {
591 processor * const proc = kernelTLS().this_processor;
592 unsigned last = proc->rdq.last;
593 if(last != MAX) {
594 struct thread$ * t = try_pop(cltr, last __STATS(, __tls_stats()->ready.pop.steal));
595 if(t) return t;
596 proc->rdq.last = MAX;
597 }
598
599 unsigned i = __tls_rand() % lanes.count;
600 return try_pop(cltr, i __STATS(, __tls_stats()->ready.pop.steal));
601 }
602 __attribute__((hot)) struct thread$ * pop_search(struct cluster * cltr) {
603 return search(cltr);
604 }
605#endif
606#if defined(USE_RELAXED_FIFO)
607 //-----------------------------------------------------------------------
608 // get index from random number with or without bias towards queues
609 static inline [unsigned, bool] idx_from_r(unsigned r, unsigned preferred) {
610 unsigned i;
611 bool local;
612 unsigned rlow = r % BIAS;
613 unsigned rhigh = r / BIAS;
614 if((0 != rlow) && preferred >= 0) {
615 // (BIAS - 1) out of BIAS chances
616 // Use perferred queues
617 i = preferred + (rhigh % READYQ_SHARD_FACTOR);
618 local = true;
619 }
620 else {
621 // 1 out of BIAS chances
622 // Use all queues
623 i = rhigh;
624 local = false;
625 }
626 return [i, local];
627 }
628
629 __attribute__((hot)) void push(struct cluster * cltr, struct thread$ * thrd, unpark_hint hint) with (cltr->ready_queue) {
630 __cfadbg_print_safe(ready_queue, "Kernel : Pushing %p on cluster %p\n", thrd, cltr);
631
632 const bool external = (hint != UNPARK_LOCAL) || (!kernelTLS().this_processor) || (cltr != kernelTLS().this_processor->cltr);
633 /* paranoid */ verify(external || kernelTLS().this_processor->rdq.id < lanes.count );
634
635 bool local;
636 int preferred = external ? -1 : kernelTLS().this_processor->rdq.id;
637
638 // Try to pick a lane and lock it
639 unsigned i;
640 do {
641 // Pick the index of a lane
642 unsigned r = __tls_rand_fwd();
643 [i, local] = idx_from_r(r, preferred);
644
645 i %= __atomic_load_n( &lanes.count, __ATOMIC_RELAXED );
646
647 #if !defined(__CFA_NO_STATISTICS__)
648 if(unlikely(external)) __atomic_fetch_add(&cltr->stats->ready.push.extrn.attempt, 1, __ATOMIC_RELAXED);
649 else if(local) __tls_stats()->ready.push.local.attempt++;
650 else __tls_stats()->ready.push.share.attempt++;
651 #endif
652
653 // If we can't lock it retry
654 } while( !__atomic_try_acquire( &lanes.data[i].lock ) );
655
656 // Actually push it
657 push(lanes.data[i], thrd);
658
659 // Unlock and return
660 __atomic_unlock( &lanes.data[i].lock );
661
662 // Mark the current index in the tls rng instance as having an item
663 __tls_rand_advance_bck();
664
665 __cfadbg_print_safe(ready_queue, "Kernel : Pushed %p on cluster %p (idx: %u, mask %llu, first %d)\n", thrd, cltr, i, used.mask[0], lane_first);
666
667 // Update statistics
668 #if !defined(__CFA_NO_STATISTICS__)
669 if(unlikely(external)) __atomic_fetch_add(&cltr->stats->ready.push.extrn.success, 1, __ATOMIC_RELAXED);
670 else if(local) __tls_stats()->ready.push.local.success++;
671 else __tls_stats()->ready.push.share.success++;
672 #endif
673 }
674
675 // Pop from the ready queue from a given cluster
676 __attribute__((hot)) thread$ * pop_fast(struct cluster * cltr) with (cltr->ready_queue) {
677 /* paranoid */ verify( lanes.count > 0 );
678 /* paranoid */ verify( kernelTLS().this_processor );
679 /* paranoid */ verify( kernelTLS().this_processor->rdq.id < lanes.count );
680
681 unsigned count = __atomic_load_n( &lanes.count, __ATOMIC_RELAXED );
682 int preferred = kernelTLS().this_processor->rdq.id;
683
684
685 // As long as the list is not empty, try finding a lane that isn't empty and pop from it
686 for(25) {
687 // Pick two lists at random
688 unsigned ri = __tls_rand_bck();
689 unsigned rj = __tls_rand_bck();
690
691 unsigned i, j;
692 __attribute__((unused)) bool locali, localj;
693 [i, locali] = idx_from_r(ri, preferred);
694 [j, localj] = idx_from_r(rj, preferred);
695
696 i %= count;
697 j %= count;
698
699 // try popping from the 2 picked lists
700 struct thread$ * thrd = try_pop(cltr, i, j __STATS(, *(locali || localj ? &__tls_stats()->ready.pop.local : &__tls_stats()->ready.pop.help)));
701 if(thrd) {
702 return thrd;
703 }
704 }
705
706 // All lanes where empty return 0p
707 return 0p;
708 }
709
710 __attribute__((hot)) struct thread$ * pop_slow(struct cluster * cltr) { return pop_fast(cltr); }
711 __attribute__((hot)) struct thread$ * pop_search(struct cluster * cltr) {
712 return search(cltr);
713 }
714#endif
715#if defined(USE_WORK_STEALING)
716 __attribute__((hot)) void push(struct cluster * cltr, struct thread$ * thrd, unpark_hint hint) with (cltr->ready_queue) {
717 __cfadbg_print_safe(ready_queue, "Kernel : Pushing %p on cluster %p\n", thrd, cltr);
718
719 // #define USE_PREFERRED
720 #if !defined(USE_PREFERRED)
721 const bool external = (hint != UNPARK_LOCAL) || (!kernelTLS().this_processor) || (cltr != kernelTLS().this_processor->cltr);
722 /* paranoid */ verify(external || kernelTLS().this_processor->rdq.id < lanes.count );
723 #else
724 unsigned preferred = thrd->preferred;
725 const bool external = (hint != UNPARK_LOCAL) || (!kernelTLS().this_processor) || preferred == MAX || thrd->curr_cluster != cltr;
726 /* paranoid */ verifyf(external || preferred < lanes.count, "Invalid preferred queue %u for %u lanes", preferred, lanes.count );
727
728 unsigned r = preferred % READYQ_SHARD_FACTOR;
729 const unsigned start = preferred - r;
730 #endif
731
732 // Try to pick a lane and lock it
733 unsigned i;
734 do {
735 #if !defined(__CFA_NO_STATISTICS__)
736 if(unlikely(external)) __atomic_fetch_add(&cltr->stats->ready.push.extrn.attempt, 1, __ATOMIC_RELAXED);
737 else __tls_stats()->ready.push.local.attempt++;
738 #endif
739
740 if(unlikely(external)) {
741 i = __tls_rand() % lanes.count;
742 }
743 else {
744 #if !defined(USE_PREFERRED)
745 processor * proc = kernelTLS().this_processor;
746 unsigned r = proc->rdq.its++;
747 i = proc->rdq.id + (r % READYQ_SHARD_FACTOR);
748 #else
749 i = start + (r++ % READYQ_SHARD_FACTOR);
750 #endif
751 }
752 // If we can't lock it retry
753 } while( !__atomic_try_acquire( &lanes.data[i].lock ) );
754
755 // Actually push it
756 push(lanes.data[i], thrd);
757
758 // Unlock and return
759 __atomic_unlock( &lanes.data[i].lock );
760
761 #if !defined(__CFA_NO_STATISTICS__)
762 if(unlikely(external)) __atomic_fetch_add(&cltr->stats->ready.push.extrn.success, 1, __ATOMIC_RELAXED);
763 else __tls_stats()->ready.push.local.success++;
764 #endif
765
766 __cfadbg_print_safe(ready_queue, "Kernel : Pushed %p on cluster %p (idx: %u, mask %llu, first %d)\n", thrd, cltr, i, used.mask[0], lane_first);
767 }
768
769 // Pop from the ready queue from a given cluster
770 __attribute__((hot)) thread$ * pop_fast(struct cluster * cltr) with (cltr->ready_queue) {
771 /* paranoid */ verify( lanes.count > 0 );
772 /* paranoid */ verify( kernelTLS().this_processor );
773 /* paranoid */ verify( kernelTLS().this_processor->rdq.id < lanes.count );
774
775 processor * proc = kernelTLS().this_processor;
776
777 if(proc->rdq.target == MAX) {
778 unsigned long long min = ts(lanes.data[proc->rdq.id]);
779 for(int i = 0; i < READYQ_SHARD_FACTOR; i++) {
780 unsigned long long tsc = ts(lanes.data[proc->rdq.id + i]);
781 if(tsc < min) min = tsc;
782 }
783 proc->rdq.cutoff = min;
784 proc->rdq.target = __tls_rand() % lanes.count;
785 }
786 else {
787 unsigned target = proc->rdq.target;
788 proc->rdq.target = MAX;
789 const unsigned long long bias = 0; //2_500_000_000;
790 const unsigned long long cutoff = proc->rdq.cutoff > bias ? proc->rdq.cutoff - bias : proc->rdq.cutoff;
791 if(lanes.tscs[target].tv < cutoff && ts(lanes.data[target]) < cutoff) {
792 thread$ * t = try_pop(cltr, target __STATS(, __tls_stats()->ready.pop.help));
793 if(t) return t;
794 }
795 }
796
797 for(READYQ_SHARD_FACTOR) {
798 unsigned i = proc->rdq.id + (proc->rdq.itr++ % READYQ_SHARD_FACTOR);
799 if(thread$ * t = try_pop(cltr, i __STATS(, __tls_stats()->ready.pop.local))) return t;
800 }
801 return 0p;
802 }
803
804 __attribute__((hot)) struct thread$ * pop_slow(struct cluster * cltr) with (cltr->ready_queue) {
805 unsigned i = __tls_rand() % lanes.count;
806 return try_pop(cltr, i __STATS(, __tls_stats()->ready.pop.steal));
807 }
808
809 __attribute__((hot)) struct thread$ * pop_search(struct cluster * cltr) with (cltr->ready_queue) {
810 return search(cltr);
811 }
812#endif
813
814//=======================================================================
815// Various Ready Queue utilities
816//=======================================================================
817// these function work the same or almost the same
818// whether they are using work-stealing or relaxed fifo scheduling
819
820//-----------------------------------------------------------------------
821// try to pop from a lane given by index w
822static inline struct thread$ * try_pop(struct cluster * cltr, unsigned w __STATS(, __stats_readyQ_pop_t & stats)) with (cltr->ready_queue) {
823 /* paranoid */ verify( w < lanes.count );
824 __STATS( stats.attempt++; )
825
826 // Get relevant elements locally
827 __intrusive_lane_t & lane = lanes.data[w];
828
829 // If list looks empty retry
830 if( is_empty(lane) ) {
831 return 0p;
832 }
833
834 // If we can't get the lock retry
835 if( !__atomic_try_acquire(&lane.lock) ) {
836 return 0p;
837 }
838
839 // If list is empty, unlock and retry
840 if( is_empty(lane) ) {
841 __atomic_unlock(&lane.lock);
842 return 0p;
843 }
844
845 // Actually pop the list
846 struct thread$ * thrd;
847 #if defined(USE_AWARE_STEALING) || defined(USE_WORK_STEALING) || defined(USE_CPU_WORK_STEALING)
848 unsigned long long tsc_before = ts(lane);
849 #endif
850 unsigned long long tsv;
851 [thrd, tsv] = pop(lane);
852
853 /* paranoid */ verify(thrd);
854 /* paranoid */ verify(tsv);
855 /* paranoid */ verify(lane.lock);
856
857 // Unlock and return
858 __atomic_unlock(&lane.lock);
859
860 // Update statistics
861 __STATS( stats.success++; )
862
863 #if defined(USE_AWARE_STEALING) || defined(USE_WORK_STEALING) || defined(USE_CPU_WORK_STEALING)
864 if (tsv != MAX) {
865 unsigned long long now = rdtscl();
866 unsigned long long pma = __atomic_load_n(&lanes.tscs[w].ma, __ATOMIC_RELAXED);
867 __atomic_store_n(&lanes.tscs[w].tv, tsv, __ATOMIC_RELAXED);
868 __atomic_store_n(&lanes.tscs[w].ma, moving_average(now, tsc_before, pma), __ATOMIC_RELAXED);
869 }
870 #endif
871
872 #if defined(USE_AWARE_STEALING) || defined(USE_CPU_WORK_STEALING)
873 thrd->preferred = w / READYQ_SHARD_FACTOR;
874 #else
875 thrd->preferred = w;
876 #endif
877
878 // return the popped thread
879 return thrd;
880}
881
882//-----------------------------------------------------------------------
883// try to pop from any lanes making sure you don't miss any threads push
884// before the start of the function
885static inline struct thread$ * search(struct cluster * cltr) with (cltr->ready_queue) {
886 /* paranoid */ verify( lanes.count > 0 );
887 unsigned count = __atomic_load_n( &lanes.count, __ATOMIC_RELAXED );
888 unsigned offset = __tls_rand();
889 for(i; count) {
890 unsigned idx = (offset + i) % count;
891 struct thread$ * thrd = try_pop(cltr, idx __STATS(, __tls_stats()->ready.pop.search));
892 if(thrd) {
893 return thrd;
894 }
895 }
896
897 // All lanes where empty return 0p
898 return 0p;
899}
900
901//-----------------------------------------------------------------------
902// get preferred ready for new thread
903unsigned ready_queue_new_preferred() {
904 unsigned pref = 0;
905 if(struct thread$ * thrd = publicTLS_get( this_thread )) {
906 pref = thrd->preferred;
907 }
908 else {
909 #if defined(USE_CPU_WORK_STEALING)
910 pref = __kernel_getcpu();
911 #endif
912 }
913
914 #if defined(USE_CPU_WORK_STEALING)
915 /* paranoid */ verify(pref >= 0);
916 /* paranoid */ verify(pref < cpu_info.hthrd_count);
917 #endif
918
919 return pref;
920}
921
922//-----------------------------------------------------------------------
923// Check that all the intrusive queues in the data structure are still consistent
924static void check( __ready_queue_t & q ) with (q) {
925 #if defined(__CFA_WITH_VERIFY__)
926 {
927 for( idx ; lanes.count ) {
928 __intrusive_lane_t & sl = lanes.data[idx];
929 assert(!lanes.data[idx].lock);
930
931 if(is_empty(sl)) {
932 assert( sl.anchor.next == 0p );
933 assert( sl.anchor.ts == -1llu );
934 assert( mock_head(sl) == sl.prev );
935 } else {
936 assert( sl.anchor.next != 0p );
937 assert( sl.anchor.ts != -1llu );
938 assert( mock_head(sl) != sl.prev );
939 }
940 }
941 }
942 #endif
943}
944
945//-----------------------------------------------------------------------
946// Given 2 indexes, pick the list with the oldest push an try to pop from it
947static inline struct thread$ * try_pop(struct cluster * cltr, unsigned i, unsigned j __STATS(, __stats_readyQ_pop_t & stats)) with (cltr->ready_queue) {
948 // Pick the bet list
949 int w = i;
950 if( __builtin_expect(!is_empty(lanes.data[j]), true) ) {
951 w = (ts(lanes.data[i]) < ts(lanes.data[j])) ? i : j;
952 }
953
954 return try_pop(cltr, w __STATS(, stats));
955}
956
957// Call this function of the intrusive list was moved using memcpy
958// fixes the list so that the pointers back to anchors aren't left dangling
959static inline void fix(__intrusive_lane_t & ll) {
960 if(is_empty(ll)) {
961 verify(ll.anchor.next == 0p);
962 ll.prev = mock_head(ll);
963 }
964}
965
966static void assign_list(unsigned & value, dlist(processor) & list, unsigned count) {
967 processor * it = &list`first;
968 for(unsigned i = 0; i < count; i++) {
969 /* paranoid */ verifyf( it, "Unexpected null iterator, at index %u of %u\n", i, count);
970 it->rdq.id = value;
971 it->rdq.target = MAX;
972 value += READYQ_SHARD_FACTOR;
973 it = &(*it)`next;
974 }
975}
976
977static void reassign_cltr_id(struct cluster * cltr) {
978 unsigned preferred = 0;
979 assign_list(preferred, cltr->procs.actives, cltr->procs.total - cltr->procs.idle);
980 assign_list(preferred, cltr->procs.idles , cltr->procs.idle );
981}
982
983static void fix_times( struct cluster * cltr ) with( cltr->ready_queue ) {
984 #if defined(USE_AWARE_STEALING) || defined(USE_WORK_STEALING)
985 lanes.tscs = alloc(lanes.count, lanes.tscs`realloc);
986 for(i; lanes.count) {
987 lanes.tscs[i].tv = rdtscl();
988 lanes.tscs[i].ma = 0;
989 }
990 #endif
991}
992
993#if defined(USE_CPU_WORK_STEALING)
994 // ready_queue size is fixed in this case
995 void ready_queue_grow(struct cluster * cltr) {}
996 void ready_queue_shrink(struct cluster * cltr) {}
997#else
998 // Grow the ready queue
999 void ready_queue_grow(struct cluster * cltr) {
1000 size_t ncount;
1001 int target = cltr->procs.total;
1002
1003 /* paranoid */ verify( ready_mutate_islocked() );
1004 __cfadbg_print_safe(ready_queue, "Kernel : Growing ready queue\n");
1005
1006 // Make sure that everything is consistent
1007 /* paranoid */ check( cltr->ready_queue );
1008
1009 // grow the ready queue
1010 with( cltr->ready_queue ) {
1011 // Find new count
1012 // Make sure we always have atleast 1 list
1013 if(target >= 2) {
1014 ncount = target * READYQ_SHARD_FACTOR;
1015 } else {
1016 ncount = SEQUENTIAL_SHARD;
1017 }
1018
1019 // Allocate new array (uses realloc and memcpies the data)
1020 lanes.data = alloc( ncount, lanes.data`realloc );
1021
1022 // Fix the moved data
1023 for( idx; (size_t)lanes.count ) {
1024 fix(lanes.data[idx]);
1025 }
1026
1027 // Construct new data
1028 for( idx; (size_t)lanes.count ~ ncount) {
1029 (lanes.data[idx]){};
1030 }
1031
1032 // Update original
1033 lanes.count = ncount;
1034
1035 lanes.caches = alloc( target, lanes.caches`realloc );
1036 }
1037
1038 fix_times(cltr);
1039
1040 reassign_cltr_id(cltr);
1041
1042 // Make sure that everything is consistent
1043 /* paranoid */ check( cltr->ready_queue );
1044
1045 __cfadbg_print_safe(ready_queue, "Kernel : Growing ready queue done\n");
1046
1047 /* paranoid */ verify( ready_mutate_islocked() );
1048 }
1049
1050 // Shrink the ready queue
1051 void ready_queue_shrink(struct cluster * cltr) {
1052 /* paranoid */ verify( ready_mutate_islocked() );
1053 __cfadbg_print_safe(ready_queue, "Kernel : Shrinking ready queue\n");
1054
1055 // Make sure that everything is consistent
1056 /* paranoid */ check( cltr->ready_queue );
1057
1058 int target = cltr->procs.total;
1059
1060 with( cltr->ready_queue ) {
1061 // Remember old count
1062 size_t ocount = lanes.count;
1063
1064 // Find new count
1065 // Make sure we always have atleast 1 list
1066 lanes.count = target >= 2 ? target * READYQ_SHARD_FACTOR: SEQUENTIAL_SHARD;
1067 /* paranoid */ verify( ocount >= lanes.count );
1068 /* paranoid */ verify( lanes.count == target * READYQ_SHARD_FACTOR || target < 2 );
1069
1070 // for printing count the number of displaced threads
1071 #if defined(__CFA_DEBUG_PRINT__) || defined(__CFA_DEBUG_PRINT_READY_QUEUE__)
1072 __attribute__((unused)) size_t displaced = 0;
1073 #endif
1074
1075 // redistribute old data
1076 for( idx; (size_t)lanes.count ~ ocount) {
1077 // Lock is not strictly needed but makes checking invariants much easier
1078 __attribute__((unused)) bool locked = __atomic_try_acquire(&lanes.data[idx].lock);
1079 verify(locked);
1080
1081 // As long as we can pop from this lane to push the threads somewhere else in the queue
1082 while(!is_empty(lanes.data[idx])) {
1083 struct thread$ * thrd;
1084 unsigned long long _;
1085 [thrd, _] = pop(lanes.data[idx]);
1086
1087 push(cltr, thrd, true);
1088
1089 // for printing count the number of displaced threads
1090 #if defined(__CFA_DEBUG_PRINT__) || defined(__CFA_DEBUG_PRINT_READY_QUEUE__)
1091 displaced++;
1092 #endif
1093 }
1094
1095 // Unlock the lane
1096 __atomic_unlock(&lanes.data[idx].lock);
1097
1098 // TODO print the queue statistics here
1099
1100 ^(lanes.data[idx]){};
1101 }
1102
1103 __cfadbg_print_safe(ready_queue, "Kernel : Shrinking ready queue displaced %zu threads\n", displaced);
1104
1105 // Allocate new array (uses realloc and memcpies the data)
1106 lanes.data = alloc( lanes.count, lanes.data`realloc );
1107
1108 // Fix the moved data
1109 for( idx; (size_t)lanes.count ) {
1110 fix(lanes.data[idx]);
1111 }
1112
1113 lanes.caches = alloc( target, lanes.caches`realloc );
1114 }
1115
1116 fix_times(cltr);
1117
1118
1119 reassign_cltr_id(cltr);
1120
1121 // Make sure that everything is consistent
1122 /* paranoid */ check( cltr->ready_queue );
1123
1124 __cfadbg_print_safe(ready_queue, "Kernel : Shrinking ready queue done\n");
1125 /* paranoid */ verify( ready_mutate_islocked() );
1126 }
1127#endif
1128
1129#if !defined(__CFA_NO_STATISTICS__)
1130 unsigned cnt(const __ready_queue_t & this, unsigned idx) {
1131 /* paranoid */ verify(this.lanes.count > idx);
1132 return this.lanes.data[idx].cnt;
1133 }
1134#endif
1135
1136
1137#if defined(CFA_HAVE_LINUX_LIBRSEQ)
1138 // No definition needed
1139#elif defined(CFA_HAVE_LINUX_RSEQ_H)
1140
1141 #if defined( __x86_64 ) || defined( __i386 )
1142 #define RSEQ_SIG 0x53053053
1143 #elif defined( __ARM_ARCH )
1144 #ifdef __ARMEB__
1145 #define RSEQ_SIG 0xf3def5e7 /* udf #24035 ; 0x5de3 (ARMv6+) */
1146 #else
1147 #define RSEQ_SIG 0xe7f5def3 /* udf #24035 ; 0x5de3 */
1148 #endif
1149 #endif
1150
1151 extern void __disable_interrupts_hard();
1152 extern void __enable_interrupts_hard();
1153
1154 static void __kernel_raw_rseq_register (void) {
1155 /* paranoid */ verify( __cfaabi_rseq.cpu_id == RSEQ_CPU_ID_UNINITIALIZED );
1156
1157 // int ret = syscall(__NR_rseq, &__cfaabi_rseq, sizeof(struct rseq), 0, (sigset_t *)0p, _NSIG / 8);
1158 int ret = syscall(__NR_rseq, &__cfaabi_rseq, sizeof(struct rseq), 0, RSEQ_SIG);
1159 if(ret != 0) {
1160 int e = errno;
1161 switch(e) {
1162 case EINVAL: abort("KERNEL ERROR: rseq register invalid argument");
1163 case ENOSYS: abort("KERNEL ERROR: rseq register no supported");
1164 case EFAULT: abort("KERNEL ERROR: rseq register with invalid argument");
1165 case EBUSY : abort("KERNEL ERROR: rseq register already registered");
1166 case EPERM : abort("KERNEL ERROR: rseq register sig argument on unregistration does not match the signature received on registration");
1167 default: abort("KERNEL ERROR: rseq register unexpected return %d", e);
1168 }
1169 }
1170 }
1171
1172 static void __kernel_raw_rseq_unregister(void) {
1173 /* paranoid */ verify( __cfaabi_rseq.cpu_id >= 0 );
1174
1175 // int ret = syscall(__NR_rseq, &__cfaabi_rseq, sizeof(struct rseq), RSEQ_FLAG_UNREGISTER, (sigset_t *)0p, _NSIG / 8);
1176 int ret = syscall(__NR_rseq, &__cfaabi_rseq, sizeof(struct rseq), RSEQ_FLAG_UNREGISTER, RSEQ_SIG);
1177 if(ret != 0) {
1178 int e = errno;
1179 switch(e) {
1180 case EINVAL: abort("KERNEL ERROR: rseq unregister invalid argument");
1181 case ENOSYS: abort("KERNEL ERROR: rseq unregister no supported");
1182 case EFAULT: abort("KERNEL ERROR: rseq unregister with invalid argument");
1183 case EBUSY : abort("KERNEL ERROR: rseq unregister already registered");
1184 case EPERM : abort("KERNEL ERROR: rseq unregister sig argument on unregistration does not match the signature received on registration");
1185 default: abort("KERNEL ERROR: rseq unregisteunexpected return %d", e);
1186 }
1187 }
1188 }
1189#else
1190 // No definition needed
1191#endif
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