1 /* 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#)vm_glue.c 8.6 (Berkeley) 1/5/94 37 * 38 * 39 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 40 * All rights reserved. 41 * 42 * Permission to use, copy, modify and distribute this software and 43 * its documentation is hereby granted, provided that both the copyright 44 * notice and this permission notice appear in all copies of the 45 * software, derivative works or modified versions, and any portions 46 * thereof, and that both notices appear in supporting documentation. 47 * 48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 51 * 52 * Carnegie Mellon requests users of this software to return to 53 * 54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 55 * School of Computer Science 56 * Carnegie Mellon University 57 * Pittsburgh PA 15213-3890 58 * 59 * any improvements or extensions that they make and grant Carnegie the 60 * rights to redistribute these changes. 61 * 62 * $Id: vm_glue.c,v 1.11 1995/01/09 16:05:40 davidg Exp $ 63 */ 64 65 #include <sys/param.h> 66 #include <sys/systm.h> 67 #include <sys/proc.h> 68 #include <sys/resourcevar.h> 69 #include <sys/buf.h> 70 #include <sys/user.h> 71 72 #include <sys/kernel.h> 73 #include <sys/dkstat.h> 74 75 #include <vm/vm.h> 76 #include <vm/vm_page.h> 77 #include <vm/vm_pageout.h> 78 #include <vm/vm_kern.h> 79 80 #include <machine/stdarg.h> 81 #include <machine/cpu.h> 82 83 extern char kstack[]; 84 int avefree = 0; /* XXX */ 85 int readbuffers = 0; /* XXX allow kgdb to read kernel buffer pool */ 86 87 /* vm_map_t upages_map; */ 88 89 int 90 kernacc(addr, len, rw) 91 caddr_t addr; 92 int len, rw; 93 { 94 boolean_t rv; 95 vm_offset_t saddr, eaddr; 96 vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE; 97 98 saddr = trunc_page(addr); 99 eaddr = round_page(addr + len); 100 rv = vm_map_check_protection(kernel_map, saddr, eaddr, prot); 101 return (rv == TRUE); 102 } 103 104 int 105 useracc(addr, len, rw) 106 caddr_t addr; 107 int len, rw; 108 { 109 boolean_t rv; 110 vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE; 111 112 /* 113 * XXX - check separately to disallow access to user area and user 114 * page tables - they are in the map. 115 * 116 * XXX - VM_MAXUSER_ADDRESS is an end address, not a max. It was once 117 * only used (as an end address) in trap.c. Use it as an end address 118 * here too. This bogusness has spread. I just fixed where it was 119 * used as a max in vm_mmap.c. 120 */ 121 if ((vm_offset_t) addr + len > /* XXX */ VM_MAXUSER_ADDRESS 122 || (vm_offset_t) addr + len < (vm_offset_t) addr) { 123 return (FALSE); 124 } 125 rv = vm_map_check_protection(&curproc->p_vmspace->vm_map, 126 trunc_page(addr), round_page(addr + len), prot); 127 return (rv == TRUE); 128 } 129 130 #ifdef KGDB 131 /* 132 * Change protections on kernel pages from addr to addr+len 133 * (presumably so debugger can plant a breakpoint). 134 * All addresses are assumed to reside in the Sysmap, 135 */ 136 chgkprot(addr, len, rw) 137 register caddr_t addr; 138 int len, rw; 139 { 140 vm_prot_t prot = rw == B_READ ? VM_PROT_READ : VM_PROT_WRITE; 141 142 vm_map_protect(kernel_map, trunc_page(addr), 143 round_page(addr + len), prot, FALSE); 144 } 145 #endif 146 void 147 vslock(addr, len) 148 caddr_t addr; 149 u_int len; 150 { 151 vm_map_pageable(&curproc->p_vmspace->vm_map, trunc_page(addr), 152 round_page(addr + len), FALSE); 153 } 154 155 void 156 vsunlock(addr, len, dirtied) 157 caddr_t addr; 158 u_int len; 159 int dirtied; 160 { 161 #ifdef lint 162 dirtied++; 163 #endif /* lint */ 164 vm_map_pageable(&curproc->p_vmspace->vm_map, trunc_page(addr), 165 round_page(addr + len), TRUE); 166 } 167 168 /* 169 * Implement fork's actions on an address space. 170 * Here we arrange for the address space to be copied or referenced, 171 * allocate a user struct (pcb and kernel stack), then call the 172 * machine-dependent layer to fill those in and make the new process 173 * ready to run. 174 * NOTE: the kernel stack may be at a different location in the child 175 * process, and thus addresses of automatic variables may be invalid 176 * after cpu_fork returns in the child process. We do nothing here 177 * after cpu_fork returns. 178 */ 179 int 180 vm_fork(p1, p2, isvfork) 181 register struct proc *p1, *p2; 182 int isvfork; 183 { 184 register struct user *up; 185 vm_offset_t addr, ptaddr; 186 int i; 187 struct vm_map *vp; 188 189 while ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_min) { 190 VM_WAIT; 191 } 192 193 /* 194 * avoid copying any of the parent's pagetables or other per-process 195 * objects that reside in the map by marking all of them 196 * non-inheritable 197 */ 198 (void) vm_map_inherit(&p1->p_vmspace->vm_map, 199 UPT_MIN_ADDRESS - UPAGES * NBPG, VM_MAX_ADDRESS, VM_INHERIT_NONE); 200 p2->p_vmspace = vmspace_fork(p1->p_vmspace); 201 202 #ifdef SYSVSHM 203 if (p1->p_vmspace->vm_shm) 204 shmfork(p1, p2, isvfork); 205 #endif 206 207 /* 208 * Allocate a wired-down (for now) pcb and kernel stack for the 209 * process 210 */ 211 212 addr = (vm_offset_t) kstack; 213 214 vp = &p2->p_vmspace->vm_map; 215 216 /* ream out old pagetables and kernel stack */ 217 (void) vm_deallocate(vp, addr, UPT_MAX_ADDRESS - addr); 218 219 /* get new pagetables and kernel stack */ 220 (void) vm_allocate(vp, &addr, UPT_MAX_ADDRESS - addr, FALSE); 221 222 /* force in the page table encompassing the UPAGES */ 223 ptaddr = trunc_page((u_int) vtopte(addr)); 224 vm_map_pageable(vp, ptaddr, ptaddr + NBPG, FALSE); 225 226 /* and force in (demand-zero) the UPAGES */ 227 vm_map_pageable(vp, addr, addr + UPAGES * NBPG, FALSE); 228 229 /* get a kernel virtual address for the UPAGES for this proc */ 230 up = (struct user *) kmem_alloc_pageable(u_map, UPAGES * NBPG); 231 232 /* and force-map the upages into the kernel pmap */ 233 for (i = 0; i < UPAGES; i++) 234 pmap_enter(vm_map_pmap(u_map), 235 ((vm_offset_t) up) + NBPG * i, 236 pmap_extract(vp->pmap, addr + NBPG * i), 237 VM_PROT_READ | VM_PROT_WRITE, 1); 238 239 /* 240 * and allow the UPAGES page table entry to be paged (at the vm system 241 * level) 242 */ 243 vm_map_pageable(vp, ptaddr, ptaddr + NBPG, TRUE); 244 245 p2->p_addr = up; 246 247 /* 248 * p_stats and p_sigacts currently point at fields in the user struct 249 * but not at &u, instead at p_addr. Copy p_sigacts and parts of 250 * p_stats; zero the rest of p_stats (statistics). 251 */ 252 p2->p_stats = &up->u_stats; 253 p2->p_sigacts = &up->u_sigacts; 254 up->u_sigacts = *p1->p_sigacts; 255 bzero(&up->u_stats.pstat_startzero, 256 (unsigned) ((caddr_t) &up->u_stats.pstat_endzero - 257 (caddr_t) &up->u_stats.pstat_startzero)); 258 bcopy(&p1->p_stats->pstat_startcopy, &up->u_stats.pstat_startcopy, 259 ((caddr_t) &up->u_stats.pstat_endcopy - 260 (caddr_t) &up->u_stats.pstat_startcopy)); 261 262 263 /* 264 * cpu_fork will copy and update the kernel stack and pcb, and make 265 * the child ready to run. It marks the child so that it can return 266 * differently than the parent. It returns twice, once in the parent 267 * process and once in the child. 268 */ 269 return (cpu_fork(p1, p2)); 270 } 271 272 /* 273 * Set default limits for VM system. 274 * Called for proc 0, and then inherited by all others. 275 */ 276 void 277 vm_init_limits(p) 278 register struct proc *p; 279 { 280 int rss_limit; 281 282 /* 283 * Set up the initial limits on process VM. Set the maximum resident 284 * set size to be half of (reasonably) available memory. Since this 285 * is a soft limit, it comes into effect only when the system is out 286 * of memory - half of main memory helps to favor smaller processes, 287 * and reduces thrashing of the object cache. 288 */ 289 p->p_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ; 290 p->p_rlimit[RLIMIT_STACK].rlim_max = MAXSSIZ; 291 p->p_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ; 292 p->p_rlimit[RLIMIT_DATA].rlim_max = MAXDSIZ; 293 /* limit the limit to no less than 2MB */ 294 rss_limit = max(cnt.v_free_count / 2, 512); 295 p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(rss_limit); 296 p->p_rlimit[RLIMIT_RSS].rlim_max = RLIM_INFINITY; 297 } 298 299 #ifdef DEBUG 300 int enableswap = 1; 301 int swapdebug = 0; 302 303 #define SDB_FOLLOW 1 304 #define SDB_SWAPIN 2 305 #define SDB_SWAPOUT 4 306 #endif 307 308 void 309 faultin(p) 310 struct proc *p; 311 { 312 vm_offset_t i; 313 vm_offset_t ptaddr; 314 int s; 315 316 if ((p->p_flag & P_INMEM) == 0) { 317 vm_map_t map; 318 319 ++p->p_lock; 320 321 map = &p->p_vmspace->vm_map; 322 /* force the page table encompassing the kernel stack (upages) */ 323 ptaddr = trunc_page((u_int) vtopte(kstack)); 324 vm_map_pageable(map, ptaddr, ptaddr + NBPG, FALSE); 325 326 /* wire in the UPAGES */ 327 vm_map_pageable(map, (vm_offset_t) kstack, 328 (vm_offset_t) kstack + UPAGES * NBPG, FALSE); 329 330 /* and map them nicely into the kernel pmap */ 331 for (i = 0; i < UPAGES; i++) { 332 vm_offset_t off = i * NBPG; 333 vm_offset_t pa = (vm_offset_t) 334 pmap_extract(&p->p_vmspace->vm_pmap, 335 (vm_offset_t) kstack + off); 336 337 pmap_enter(vm_map_pmap(u_map), 338 ((vm_offset_t) p->p_addr) + off, 339 pa, VM_PROT_READ | VM_PROT_WRITE, 1); 340 } 341 342 /* and let the page table pages go (at least above pmap level) */ 343 vm_map_pageable(map, ptaddr, ptaddr + NBPG, TRUE); 344 345 s = splhigh(); 346 347 if (p->p_stat == SRUN) 348 setrunqueue(p); 349 350 p->p_flag |= P_INMEM; 351 352 /* undo the effect of setting SLOCK above */ 353 --p->p_lock; 354 splx(s); 355 356 } 357 } 358 359 /* 360 * This swapin algorithm attempts to swap-in processes only if there 361 * is enough space for them. Of course, if a process waits for a long 362 * time, it will be swapped in anyway. 363 */ 364 void 365 scheduler() 366 { 367 register struct proc *p; 368 register int pri; 369 struct proc *pp; 370 int ppri; 371 372 loop: 373 while ((cnt.v_free_count + cnt.v_cache_count) < (cnt.v_free_reserved + UPAGES + 2)) { 374 VM_WAIT; 375 tsleep((caddr_t) &proc0, PVM, "schedm", 0); 376 } 377 378 pp = NULL; 379 ppri = INT_MIN; 380 for (p = (struct proc *) allproc; p != NULL; p = p->p_next) { 381 if (p->p_stat == SRUN && (p->p_flag & (P_INMEM | P_SWAPPING)) == 0) { 382 int mempri; 383 384 pri = p->p_swtime + p->p_slptime - p->p_nice * 8; 385 mempri = pri > 0 ? pri : 0; 386 /* 387 * if this process is higher priority and there is 388 * enough space, then select this process instead of 389 * the previous selection. 390 */ 391 if (pri > ppri) { 392 pp = p; 393 ppri = pri; 394 } 395 } 396 } 397 398 /* 399 * Nothing to do, back to sleep 400 */ 401 if ((p = pp) == NULL) { 402 tsleep((caddr_t) &proc0, PVM, "sched", 0); 403 goto loop; 404 } 405 /* 406 * We would like to bring someone in. (only if there is space). 407 */ 408 faultin(p); 409 p->p_swtime = 0; 410 goto loop; 411 } 412 413 #define swappable(p) \ 414 (((p)->p_lock == 0) && \ 415 ((p)->p_flag & (P_TRACED|P_NOSWAP|P_SYSTEM|P_INMEM|P_WEXIT|P_PHYSIO|P_SWAPPING)) == P_INMEM) 416 417 extern int vm_pageout_free_min; 418 419 /* 420 * Swapout is driven by the pageout daemon. Very simple, we find eligible 421 * procs and unwire their u-areas. We try to always "swap" at least one 422 * process in case we need the room for a swapin. 423 * If any procs have been sleeping/stopped for at least maxslp seconds, 424 * they are swapped. Else, we swap the longest-sleeping or stopped process, 425 * if any, otherwise the longest-resident process. 426 */ 427 void 428 swapout_threads() 429 { 430 register struct proc *p; 431 struct proc *outp, *outp2; 432 int outpri, outpri2; 433 int tpri; 434 int didswap = 0; 435 extern int maxslp; 436 437 outp = outp2 = NULL; 438 outpri = outpri2 = INT_MIN; 439 retry: 440 for (p = (struct proc *) allproc; p != NULL; p = p->p_next) { 441 if (!swappable(p)) 442 continue; 443 switch (p->p_stat) { 444 default: 445 continue; 446 447 case SSLEEP: 448 case SSTOP: 449 /* 450 * do not swapout a realtime process 451 */ 452 if (p->p_rtprio.type == RTP_PRIO_REALTIME) 453 continue; 454 455 /* 456 * do not swapout a process waiting on a critical 457 * event of some kind 458 */ 459 if ((p->p_priority & 0x7f) < PSOCK) 460 continue; 461 462 /* 463 * do not swapout a process that is waiting for VM 464 * datastructures there is a possible deadlock. 465 */ 466 if (!lock_try_write(&p->p_vmspace->vm_map.lock)) { 467 continue; 468 } 469 vm_map_unlock(&p->p_vmspace->vm_map); 470 /* 471 * If the process has been asleep for awhile and had 472 * most of its pages taken away already, swap it out. 473 */ 474 if (p->p_slptime > maxslp) { 475 swapout(p); 476 didswap++; 477 goto retry; 478 } 479 } 480 } 481 /* 482 * If we swapped something out, and another process needed memory, 483 * then wakeup the sched process. 484 */ 485 if (didswap) 486 wakeup((caddr_t) &proc0); 487 } 488 489 void 490 swapout(p) 491 register struct proc *p; 492 { 493 vm_map_t map = &p->p_vmspace->vm_map; 494 495 ++p->p_stats->p_ru.ru_nswap; 496 /* 497 * remember the process resident count 498 */ 499 p->p_vmspace->vm_swrss = 500 p->p_vmspace->vm_pmap.pm_stats.resident_count; 501 502 (void) splhigh(); 503 p->p_flag &= ~P_INMEM; 504 if (p->p_stat == SRUN) 505 remrq(p); 506 (void) spl0(); 507 508 p->p_flag |= P_SWAPPING; 509 /* 510 * let the upages be paged 511 */ 512 pmap_remove(vm_map_pmap(u_map), 513 (vm_offset_t) p->p_addr, ((vm_offset_t) p->p_addr) + UPAGES * NBPG); 514 515 vm_map_pageable(map, (vm_offset_t) kstack, 516 (vm_offset_t) kstack + UPAGES * NBPG, TRUE); 517 518 p->p_flag &= ~P_SWAPPING; 519 p->p_swtime = 0; 520 } 521 522 /* 523 * The rest of these routines fake thread handling 524 */ 525 526 #ifndef assert_wait 527 void 528 assert_wait(event, ruptible) 529 int event; 530 boolean_t ruptible; 531 { 532 #ifdef lint 533 ruptible++; 534 #endif 535 curproc->p_thread = event; 536 } 537 #endif 538 539 void 540 thread_block(char *msg) 541 { 542 if (curproc->p_thread) 543 tsleep((caddr_t) curproc->p_thread, PVM, msg, 0); 544 } 545 546 547 void 548 thread_sleep_(event, lock, wmesg) 549 int event; 550 simple_lock_t lock; 551 char *wmesg; 552 { 553 554 curproc->p_thread = event; 555 simple_unlock(lock); 556 if (curproc->p_thread) { 557 tsleep((caddr_t) event, PVM, wmesg, 0); 558 } 559 } 560 561 #ifndef thread_wakeup 562 void 563 thread_wakeup(event) 564 int event; 565 { 566 wakeup((caddr_t) event); 567 } 568 #endif 569 570 /* 571 * DEBUG stuff 572 */ 573 574 int indent = 0; 575 576 #include <machine/stdarg.h> /* see subr_prf.c */ 577 578 /*ARGSUSED2*/ 579 void 580 #if __STDC__ 581 iprintf(const char *fmt,...) 582 #else 583 iprintf(fmt /* , va_alist */ ) 584 char *fmt; 585 586 /* va_dcl */ 587 #endif 588 { 589 register int i; 590 va_list ap; 591 592 for (i = indent; i >= 8; i -= 8) 593 printf("\t"); 594 while (--i >= 0) 595 printf(" "); 596 va_start(ap, fmt); 597 printf("%r", fmt, ap); 598 va_end(ap); 599 } 600