1 /* $NetBSD: lwp.h,v 1.193 2020/01/08 17:38:43 ad Exp $ */ 2 3 /* 4 * Copyright (c) 2001, 2006, 2007, 2008, 2009, 2010, 2019 5 * The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Nathan J. Williams and Andrew Doran. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #ifndef _SYS_LWP_H_ 34 #define _SYS_LWP_H_ 35 36 #if defined(_KERNEL) || defined(_KMEMUSER) 37 38 #include <sys/param.h> 39 #include <sys/time.h> 40 #include <sys/queue.h> 41 #include <sys/callout.h> 42 #include <sys/kcpuset.h> 43 #include <sys/mutex.h> 44 #include <sys/condvar.h> 45 #include <sys/signalvar.h> 46 #include <sys/sched.h> 47 #include <sys/specificdata.h> 48 #include <sys/syncobj.h> 49 #include <sys/resource.h> 50 51 #if defined(_KERNEL) 52 struct lwp; 53 /* forward declare this for <machine/cpu.h> so it can get l_cpu. */ 54 static __inline struct cpu_info *lwp_getcpu(struct lwp *); 55 #include <machine/cpu.h> /* curcpu() and cpu_info */ 56 #ifdef _KERNEL_OPT 57 #include "opt_kmsan.h" 58 #endif 59 #endif 60 61 #include <machine/proc.h> /* Machine-dependent proc substruct. */ 62 63 /* 64 * Lightweight process. Field markings and the corresponding locks: 65 * 66 * a: proc_lock 67 * c: condition variable interlock, passed to cv_wait() 68 * l: *l_mutex 69 * p: l_proc->p_lock 70 * s: spc_mutex, which may or may not be referenced by l_mutex 71 * S: l_selcluster->sc_lock 72 * (: unlocked, stable 73 * !: unlocked, may only be reliably accessed by the LWP itself 74 * 75 * Fields are clustered together by usage (to increase the likelihood 76 * of cache hits) and by size (to reduce dead space in the structure). 77 */ 78 79 #include <sys/pcu.h> 80 81 struct lockdebug; 82 struct sysent; 83 84 struct lwp { 85 /* Scheduling and overall state. */ 86 TAILQ_ENTRY(lwp) l_runq; /* s: run queue */ 87 union { 88 void * info; /* s: scheduler-specific structure */ 89 u_int timeslice; /* l: time-quantum for SCHED_M2 */ 90 } l_sched; 91 struct cpu_info *volatile l_cpu;/* s: CPU we're on if LSONPROC */ 92 kmutex_t * volatile l_mutex; /* l: ptr to mutex on sched state */ 93 void *l_addr; /* l: PCB address; use lwp_getpcb() */ 94 struct mdlwp l_md; /* l: machine-dependent fields. */ 95 int l_flag; /* l: misc flag values */ 96 int l_stat; /* l: overall LWP status */ 97 struct bintime l_rtime; /* l: real time */ 98 struct bintime l_stime; /* l: start time (while ONPROC) */ 99 u_int l_swtime; /* l: time swapped in or out */ 100 u_int l_rticks; /* l: Saved start time of run */ 101 u_int l_rticksum; /* l: Sum of ticks spent running */ 102 u_int l_slpticks; /* l: Saved start time of sleep */ 103 u_int l_slpticksum; /* l: Sum of ticks spent sleeping */ 104 int l_biglocks; /* l: biglock count before sleep */ 105 int l_class; /* l: scheduling class */ 106 int l_kpriority; /* !: has kernel priority boost */ 107 pri_t l_kpribase; /* !: kernel priority base level */ 108 pri_t l_priority; /* l: scheduler priority */ 109 pri_t l_inheritedprio;/* l: inherited priority */ 110 pri_t l_protectprio; /* l: for PTHREAD_PRIO_PROTECT */ 111 pri_t l_auxprio; /* l: max(inherit,protect) priority */ 112 int l_protectdepth; /* l: for PTHREAD_PRIO_PROTECT */ 113 SLIST_HEAD(, turnstile) l_pi_lenders; /* l: ts lending us priority */ 114 volatile uint64_t l_ncsw; /* l: total context switches */ 115 volatile uint64_t l_nivcsw; /* l: involuntary context switches */ 116 u_int l_cpticks; /* (: Ticks of CPU time */ 117 fixpt_t l_pctcpu; /* p: %cpu during l_swtime */ 118 fixpt_t l_estcpu; /* l: cpu time for SCHED_4BSD */ 119 psetid_t l_psid; /* l: assigned processor-set ID */ 120 struct cpu_info *l_target_cpu; /* l: target CPU to migrate */ 121 struct lwpctl *l_lwpctl; /* p: lwpctl block kernel address */ 122 struct lcpage *l_lcpage; /* p: lwpctl containing page */ 123 kcpuset_t *l_affinity; /* l: CPU set for affinity */ 124 125 /* Synchronisation. */ 126 struct turnstile *l_ts; /* l: current turnstile */ 127 struct syncobj *l_syncobj; /* l: sync object operations set */ 128 TAILQ_ENTRY(lwp) l_sleepchain; /* l: sleep queue */ 129 wchan_t l_wchan; /* l: sleep address */ 130 const char *l_wmesg; /* l: reason for sleep */ 131 struct sleepq *l_sleepq; /* l: current sleep queue */ 132 int l_sleeperr; /* !: error before unblock */ 133 u_int l_slptime; /* l: time since last blocked */ 134 callout_t l_timeout_ch; /* !: callout for tsleep */ 135 u_int l_emap_gen; /* !: emap generation number */ 136 kcondvar_t l_waitcv; /* a: vfork() wait */ 137 bool l_vforkwaiting; /* a: vfork() waiting */ 138 139 #if PCU_UNIT_COUNT > 0 140 struct cpu_info * volatile l_pcu_cpu[PCU_UNIT_COUNT]; 141 uint32_t l_pcu_valid; 142 #endif 143 144 /* Process level and global state, misc. */ 145 LIST_ENTRY(lwp) l_list; /* a: entry on list of all LWPs */ 146 void *l_ctxlink; /* p: uc_link {get,set}context */ 147 struct proc *l_proc; /* p: parent process */ 148 LIST_ENTRY(lwp) l_sibling; /* p: entry on proc's list of LWPs */ 149 lwpid_t l_waiter; /* p: first LWP waiting on us */ 150 lwpid_t l_waitingfor; /* p: specific LWP we are waiting on */ 151 int l_prflag; /* p: process level flags */ 152 u_int l_refcnt; /* p: reference count on this LWP */ 153 lwpid_t l_lid; /* (: LWP identifier; local to proc */ 154 char *l_name; /* (: name, optional */ 155 156 /* State of select() or poll(). */ 157 int l_selflag; /* S: polling state flags */ 158 SLIST_HEAD(,selinfo) l_selwait; /* S: descriptors waited on */ 159 int l_selret; /* S: return value of select/poll */ 160 uintptr_t l_selrec; /* !: argument for selrecord() */ 161 struct selcluster *l_selcluster;/* !: associated cluster data */ 162 void * l_selbits; /* (: select() bit-field */ 163 size_t l_selni; /* (: size of a single bit-field */ 164 165 /* Signals. */ 166 int l_sigrestore; /* p: need to restore old sig mask */ 167 sigset_t l_sigwaitset; /* p: signals being waited for */ 168 kcondvar_t l_sigcv; /* p: for sigsuspend() */ 169 struct ksiginfo *l_sigwaited; /* p: delivered signals from set */ 170 sigpend_t *l_sigpendset; /* p: XXX issignal()/postsig() baton */ 171 LIST_ENTRY(lwp) l_sigwaiter; /* p: chain on list of waiting LWPs */ 172 stack_t l_sigstk; /* p: sp & on stack state variable */ 173 sigset_t l_sigmask; /* p: signal mask */ 174 sigpend_t l_sigpend; /* p: signals to this LWP */ 175 sigset_t l_sigoldmask; /* p: mask for sigpause */ 176 177 /* Private data. */ 178 specificdata_reference 179 l_specdataref; /* !: subsystem lwp-specific data */ 180 struct timespec l_ktrcsw; /* !: for ktrace CSW trace XXX */ 181 void *l_private; /* !: svr4-style lwp-private data */ 182 struct lwp *l_switchto; /* !: mi_switch: switch to this LWP */ 183 struct kauth_cred *l_cred; /* !: cached credentials */ 184 struct filedesc *l_fd; /* !: cached copy of proc::p_fd */ 185 void *l_emuldata; /* !: kernel lwp-private data */ 186 struct fstrans_lwp_info *l_fstrans; /* (: fstrans private data */ 187 u_int l_cv_signalled; /* c: restarted by cv_signal() */ 188 u_short l_shlocks; /* !: lockdebug: shared locks held */ 189 u_short l_exlocks; /* !: lockdebug: excl. locks held */ 190 u_short l_psrefs; /* !: count of psref held */ 191 u_short l_blcnt; /* !: count of kernel_lock held */ 192 int l_nopreempt; /* !: don't preempt me! */ 193 u_int l_dopreempt; /* s: kernel preemption pending */ 194 int l_pflag; /* !: LWP private flags */ 195 int l_dupfd; /* !: side return from cloning devs XXX */ 196 const struct sysent * volatile l_sysent;/* !: currently active syscall */ 197 struct rusage l_ru; /* !: accounting information */ 198 uint64_t l_pfailtime; /* !: for kernel preemption */ 199 uintptr_t l_pfailaddr; /* !: for kernel preemption */ 200 uintptr_t l_pfaillock; /* !: for kernel preemption */ 201 _TAILQ_HEAD(,struct lockdebug,volatile) l_ld_locks;/* !: locks held by LWP */ 202 int l_tcgen; /* !: for timecounter removal */ 203 204 /* These are only used by 'options SYSCALL_TIMES'. */ 205 uint32_t l_syscall_time; /* !: time epoch for current syscall */ 206 uint64_t *l_syscall_counter; /* !: counter for current process */ 207 208 struct kdtrace_thread *l_dtrace; /* (: DTrace-specific data. */ 209 210 #ifdef KMSAN 211 void *l_kmsan; /* !: KMSAN private data. */ 212 #endif 213 }; 214 215 /* 216 * UAREA_PCB_OFFSET: an offset of PCB structure in the uarea. MD code may 217 * define it in <machine/proc.h>, to indicate a different uarea layout. 218 */ 219 #ifndef UAREA_PCB_OFFSET 220 #define UAREA_PCB_OFFSET 0 221 #endif 222 223 LIST_HEAD(lwplist, lwp); /* A list of LWPs. */ 224 225 #ifdef _KERNEL 226 extern struct lwplist alllwp; /* List of all LWPs. */ 227 extern lwp_t lwp0; /* LWP for proc0. */ 228 extern int maxlwp __read_mostly; /* max number of lwps */ 229 #ifndef MAXLWP 230 #define MAXLWP 2048 231 #endif 232 #ifndef __HAVE_CPU_MAXLWP 233 #define cpu_maxlwp() MAXLWP 234 #endif 235 #endif 236 237 #endif /* _KERNEL || _KMEMUSER */ 238 239 /* These flags are kept in l_flag. */ 240 #define LW_IDLE 0x00000001 /* Idle lwp. */ 241 #define LW_LWPCTL 0x00000002 /* Adjust lwpctl in userret */ 242 #define LW_CVLOCKDEBUG 0x00000004 /* Waker does lockdebug */ 243 #define LW_SINTR 0x00000080 /* Sleep is interruptible. */ 244 #define LW_SYSTEM 0x00000200 /* Kernel thread */ 245 #define LW_DBGSUSPEND 0x00010000 /* Suspend by debugger */ 246 #define LW_WSUSPEND 0x00020000 /* Suspend before return to user */ 247 #define LW_BATCH 0x00040000 /* LWP tends to hog CPU */ 248 #define LW_WCORE 0x00080000 /* Stop for core dump on return to user */ 249 #define LW_WEXIT 0x00100000 /* Exit before return to user */ 250 #define LW_PENDSIG 0x01000000 /* Pending signal for us */ 251 #define LW_CANCELLED 0x02000000 /* tsleep should not sleep */ 252 #define LW_WREBOOT 0x08000000 /* System is rebooting, please suspend */ 253 #define LW_UNPARKED 0x10000000 /* Unpark op pending */ 254 #define LW_RUNNING 0x20000000 /* Active on a CPU */ 255 #define LW_RUMP_CLEAR 0x40000000 /* Clear curlwp in RUMP scheduler */ 256 #define LW_RUMP_QEXIT 0x80000000 /* LWP should exit ASAP */ 257 258 /* The second set of flags is kept in l_pflag. */ 259 #define LP_KTRACTIVE 0x00000001 /* Executing ktrace operation */ 260 #define LP_KTRCSW 0x00000002 /* ktrace context switch marker */ 261 #define LP_KTRCSWUSER 0x00000004 /* ktrace context switch marker */ 262 #define LP_PIDLID 0x00000008 /* free LID from PID space on exit */ 263 #define LP_OWEUPC 0x00000010 /* Owe user profiling tick */ 264 #define LP_MPSAFE 0x00000020 /* Starts life without kernel_lock */ 265 #define LP_INTR 0x00000040 /* Soft interrupt handler */ 266 #define LP_SYSCTLWRITE 0x00000080 /* sysctl write lock held */ 267 #define LP_MUSTJOIN 0x00000100 /* Must join kthread on exit */ 268 #define LP_SINGLESTEP 0x00000400 /* Single step thread in ptrace(2) */ 269 #define LP_TIMEINTR 0x00010000 /* Time this soft interrupt */ 270 #define LP_PREEMPTING 0x00020000 /* mi_switch called involuntarily */ 271 #define LP_BOUND 0x80000000 /* Bound to a CPU */ 272 273 /* The third set is kept in l_prflag. */ 274 #define LPR_DETACHED 0x00800000 /* Won't be waited for. */ 275 #define LPR_CRMOD 0x00000100 /* Credentials modified */ 276 277 /* 278 * Mask indicating that there is "exceptional" work to be done on return to 279 * user. 280 */ 281 #define LW_USERRET \ 282 (LW_WEXIT | LW_PENDSIG | LW_WREBOOT | LW_WSUSPEND | LW_WCORE | LW_LWPCTL) 283 284 /* 285 * Status values. 286 * 287 * A note about LSRUN and LSONPROC: LSRUN indicates that a process is 288 * runnable but *not* yet running, i.e. is on a run queue. LSONPROC 289 * indicates that the process is actually executing on a CPU, i.e. 290 * it is no longer on a run queue. 291 * 292 * These values are set in stone and must not be reused with future changes. 293 */ 294 #define LSIDL 1 /* Process being created by fork. */ 295 #define LSRUN 2 /* Currently runnable. */ 296 #define LSSLEEP 3 /* Sleeping on an address. */ 297 #define LSSTOP 4 /* Process debugging or suspension. */ 298 #define LSZOMB 5 /* Awaiting collection by parent. */ 299 /* define LSDEAD 6 Process is almost a zombie. (removed in 5.0) */ 300 #define LSONPROC 7 /* Process is currently on a CPU. */ 301 #define LSSUSPENDED 8 /* Not running, not signalable. */ 302 303 #if defined(_KERNEL) || defined(_KMEMUSER) 304 static __inline void * 305 lwp_getpcb(struct lwp *l) 306 { 307 308 return l->l_addr; 309 } 310 #endif /* _KERNEL || _KMEMUSER */ 311 312 #ifdef _KERNEL 313 #define LWP_CACHE_CREDS(l, p) \ 314 do { \ 315 (void)p; \ 316 if (__predict_false((l)->l_prflag & LPR_CRMOD)) \ 317 lwp_update_creds(l); \ 318 } while (/* CONSTCOND */ 0) 319 320 void lwpinit(void); 321 void lwp0_init(void); 322 void lwp_sys_init(void); 323 324 void lwp_startup(lwp_t *, lwp_t *); 325 void startlwp(void *); 326 327 int lwp_locked(lwp_t *, kmutex_t *); 328 kmutex_t *lwp_setlock(lwp_t *, kmutex_t *); 329 void lwp_unlock_to(lwp_t *, kmutex_t *); 330 int lwp_trylock(lwp_t *); 331 void lwp_addref(lwp_t *); 332 void lwp_delref(lwp_t *); 333 void lwp_delref2(lwp_t *); 334 void lwp_drainrefs(lwp_t *); 335 bool lwp_alive(lwp_t *); 336 lwp_t *lwp_find_first(proc_t *); 337 338 int lwp_wait(lwp_t *, lwpid_t, lwpid_t *, bool); 339 void lwp_continue(lwp_t *); 340 void lwp_unsleep(lwp_t *, bool); 341 void lwp_unstop(lwp_t *); 342 void lwp_exit(lwp_t *); 343 int lwp_suspend(lwp_t *, lwp_t *); 344 int lwp_create1(lwp_t *, const void *, size_t, u_long, lwpid_t *); 345 void lwp_start(lwp_t *, int); 346 void lwp_update_creds(lwp_t *); 347 void lwp_migrate(lwp_t *, struct cpu_info *); 348 lwp_t * lwp_find2(pid_t, lwpid_t); 349 lwp_t * lwp_find(proc_t *, int); 350 void lwp_userret(lwp_t *); 351 void lwp_need_userret(lwp_t *); 352 void lwp_free(lwp_t *, bool, bool); 353 uint64_t lwp_pctr(void); 354 int lwp_setprivate(lwp_t *, void *); 355 int do_lwp_create(lwp_t *, void *, u_long, lwpid_t *, const sigset_t *, 356 const stack_t *); 357 358 void lwpinit_specificdata(void); 359 int lwp_specific_key_create(specificdata_key_t *, specificdata_dtor_t); 360 void lwp_specific_key_delete(specificdata_key_t); 361 void lwp_initspecific(lwp_t *); 362 void lwp_finispecific(lwp_t *); 363 void *lwp_getspecific(specificdata_key_t); 364 #if defined(_LWP_API_PRIVATE) 365 void *_lwp_getspecific_by_lwp(lwp_t *, specificdata_key_t); 366 #endif 367 void lwp_setspecific(specificdata_key_t, void *); 368 void lwp_setspecific_by_lwp(lwp_t *, specificdata_key_t, void *); 369 370 /* Syscalls. */ 371 int lwp_park(clockid_t, int, struct timespec *, const void *); 372 int lwp_unpark(lwpid_t, const void *); 373 374 /* DDB. */ 375 void lwp_whatis(uintptr_t, void (*)(const char *, ...) __printflike(1, 2)); 376 377 /* 378 * Lock an LWP. XXX _MODULE 379 */ 380 static __inline void 381 lwp_lock(lwp_t *l) 382 { 383 kmutex_t *old = l->l_mutex; 384 385 /* 386 * Note: mutex_spin_enter() will have posted a read barrier. 387 * Re-test l->l_mutex. If it has changed, we need to try again. 388 */ 389 mutex_spin_enter(old); 390 while (__predict_false(l->l_mutex != old)) { 391 mutex_spin_exit(old); 392 old = l->l_mutex; 393 mutex_spin_enter(old); 394 } 395 } 396 397 /* 398 * Unlock an LWP. XXX _MODULE 399 */ 400 static __inline void 401 lwp_unlock(lwp_t *l) 402 { 403 mutex_spin_exit(l->l_mutex); 404 } 405 406 static __inline void 407 lwp_changepri(lwp_t *l, pri_t pri) 408 { 409 KASSERT(mutex_owned(l->l_mutex)); 410 411 if (l->l_priority == pri) 412 return; 413 414 (*l->l_syncobj->sobj_changepri)(l, pri); 415 KASSERT(l->l_priority == pri); 416 } 417 418 static __inline void 419 lwp_lendpri(lwp_t *l, pri_t pri) 420 { 421 KASSERT(mutex_owned(l->l_mutex)); 422 423 (*l->l_syncobj->sobj_lendpri)(l, pri); 424 KASSERT(l->l_inheritedprio == pri); 425 } 426 427 static __inline pri_t 428 lwp_eprio(lwp_t *l) 429 { 430 pri_t pri; 431 432 pri = l->l_priority; 433 if ((l->l_flag & LW_SYSTEM) == 0 && l->l_kpriority && pri < PRI_KERNEL) 434 pri = (pri >> 1) + l->l_kpribase; 435 return MAX(l->l_auxprio, pri); 436 } 437 438 int lwp_create(lwp_t *, struct proc *, vaddr_t, int, void *, size_t, 439 void (*)(void *), void *, lwp_t **, int, const sigset_t *, const stack_t *); 440 441 /* 442 * XXX _MODULE 443 * We should provide real stubs for the below that modules can use. 444 */ 445 446 static __inline void 447 spc_lock(struct cpu_info *ci) 448 { 449 mutex_spin_enter(ci->ci_schedstate.spc_mutex); 450 } 451 452 static __inline void 453 spc_unlock(struct cpu_info *ci) 454 { 455 mutex_spin_exit(ci->ci_schedstate.spc_mutex); 456 } 457 458 static __inline void 459 spc_dlock(struct cpu_info *ci1, struct cpu_info *ci2) 460 { 461 struct schedstate_percpu *spc1 = &ci1->ci_schedstate; 462 struct schedstate_percpu *spc2 = &ci2->ci_schedstate; 463 464 KASSERT(ci1 != ci2); 465 if (ci1 < ci2) { 466 mutex_spin_enter(spc1->spc_mutex); 467 mutex_spin_enter(spc2->spc_mutex); 468 } else { 469 mutex_spin_enter(spc2->spc_mutex); 470 mutex_spin_enter(spc1->spc_mutex); 471 } 472 } 473 474 /* 475 * Allow machine-dependent code to override curlwp in <machine/cpu.h> for 476 * its own convenience. Otherwise, we declare it as appropriate. 477 */ 478 #if !defined(curlwp) 479 #if defined(MULTIPROCESSOR) 480 #define curlwp curcpu()->ci_curlwp /* Current running LWP */ 481 #else 482 extern struct lwp *curlwp; /* Current running LWP */ 483 #endif /* MULTIPROCESSOR */ 484 #endif /* ! curlwp */ 485 #define curproc (curlwp->l_proc) 486 487 /* 488 * This provide a way for <machine/cpu.h> to get l_cpu for curlwp before 489 * struct lwp is defined. 490 */ 491 static __inline struct cpu_info * 492 lwp_getcpu(struct lwp *l) 493 { 494 return l->l_cpu; 495 } 496 497 static __inline bool 498 CURCPU_IDLE_P(void) 499 { 500 struct cpu_info *ci = curcpu(); 501 return ci->ci_onproc == ci->ci_data.cpu_idlelwp; 502 } 503 504 /* 505 * Disable and re-enable preemption. Only for low-level kernel 506 * use. Device drivers and anything that could potentially be 507 * compiled as a module should use kpreempt_disable() and 508 * kpreempt_enable(). 509 */ 510 static __inline void 511 KPREEMPT_DISABLE(lwp_t *l) 512 { 513 514 KASSERT(l == curlwp); 515 l->l_nopreempt++; 516 __insn_barrier(); 517 } 518 519 static __inline void 520 KPREEMPT_ENABLE(lwp_t *l) 521 { 522 523 KASSERT(l == curlwp); 524 KASSERT(l->l_nopreempt > 0); 525 __insn_barrier(); 526 if (--l->l_nopreempt != 0) 527 return; 528 __insn_barrier(); 529 if (__predict_false(l->l_dopreempt)) 530 kpreempt(0); 531 __insn_barrier(); 532 } 533 534 /* For lwp::l_dopreempt */ 535 #define DOPREEMPT_ACTIVE 0x01 536 #define DOPREEMPT_COUNTED 0x02 537 538 /* 539 * Prevent curlwp from migrating between CPUs between curlwp_bind and 540 * curlwp_bindx. One use case is psref(9) that has a contract that 541 * forbids migrations. 542 */ 543 static __inline int 544 curlwp_bind(void) 545 { 546 int bound; 547 548 bound = curlwp->l_pflag & LP_BOUND; 549 curlwp->l_pflag |= LP_BOUND; 550 __insn_barrier(); 551 552 return bound; 553 } 554 555 static __inline void 556 curlwp_bindx(int bound) 557 { 558 559 KASSERT(curlwp->l_pflag & LP_BOUND); 560 __insn_barrier(); 561 curlwp->l_pflag ^= bound ^ LP_BOUND; 562 } 563 564 #endif /* _KERNEL */ 565 566 /* Flags for _lwp_create(), as per Solaris. */ 567 #define LWP_DETACHED 0x00000040 568 #define LWP_SUSPENDED 0x00000080 569 570 /* Kernel-internal flags for LWP creation. */ 571 #define LWP_PIDLID 0x40000000 572 #define LWP_VFORK 0x80000000 573 574 #endif /* !_SYS_LWP_H_ */ 575