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 * $FreeBSD$ 63 */ 64 65 #include "opt_rlimit.h" 66 #include "opt_vm.h" 67 68 #include <sys/param.h> 69 #include <sys/systm.h> 70 #include <sys/proc.h> 71 #include <sys/resourcevar.h> 72 #include <sys/buf.h> 73 #include <sys/shm.h> 74 #include <sys/vmmeter.h> 75 #include <sys/sysctl.h> 76 77 #include <sys/kernel.h> 78 #include <sys/unistd.h> 79 80 #include <machine/limits.h> 81 82 #include <vm/vm.h> 83 #include <vm/vm_param.h> 84 #include <sys/lock.h> 85 #include <vm/pmap.h> 86 #include <vm/vm_map.h> 87 #include <vm/vm_page.h> 88 #include <vm/vm_pageout.h> 89 #include <vm/vm_kern.h> 90 #include <vm/vm_extern.h> 91 92 #include <sys/user.h> 93 94 /* 95 * System initialization 96 * 97 * Note: proc0 from proc.h 98 */ 99 100 static void vm_init_limits __P((void *)); 101 SYSINIT(vm_limits, SI_SUB_VM_CONF, SI_ORDER_FIRST, vm_init_limits, &proc0) 102 103 /* 104 * THIS MUST BE THE LAST INITIALIZATION ITEM!!! 105 * 106 * Note: run scheduling should be divorced from the vm system. 107 */ 108 static void scheduler __P((void *)); 109 SYSINIT(scheduler, SI_SUB_RUN_SCHEDULER, SI_ORDER_FIRST, scheduler, NULL) 110 111 112 static void swapout __P((struct proc *)); 113 114 int 115 kernacc(addr, len, rw) 116 caddr_t addr; 117 int len, rw; 118 { 119 boolean_t rv; 120 vm_offset_t saddr, eaddr; 121 vm_prot_t prot; 122 123 KASSERT((rw & (~VM_PROT_ALL)) == 0, 124 ("illegal ``rw'' argument to kernacc (%x)\n", rw)); 125 prot = rw; 126 saddr = trunc_page((vm_offset_t)addr); 127 eaddr = round_page((vm_offset_t)addr + len); 128 vm_map_lock_read(kernel_map); 129 rv = vm_map_check_protection(kernel_map, saddr, eaddr, prot); 130 vm_map_unlock_read(kernel_map); 131 return (rv == TRUE); 132 } 133 134 int 135 useracc(addr, len, rw) 136 caddr_t addr; 137 int len, rw; 138 { 139 boolean_t rv; 140 vm_prot_t prot; 141 vm_map_t map; 142 vm_map_entry_t save_hint; 143 144 KASSERT((rw & (~VM_PROT_ALL)) == 0, 145 ("illegal ``rw'' argument to useracc (%x)\n", rw)); 146 prot = rw; 147 /* 148 * XXX - check separately to disallow access to user area and user 149 * page tables - they are in the map. 150 * 151 * XXX - VM_MAXUSER_ADDRESS is an end address, not a max. It was once 152 * only used (as an end address) in trap.c. Use it as an end address 153 * here too. This bogusness has spread. I just fixed where it was 154 * used as a max in vm_mmap.c. 155 */ 156 if ((vm_offset_t) addr + len > /* XXX */ VM_MAXUSER_ADDRESS 157 || (vm_offset_t) addr + len < (vm_offset_t) addr) { 158 return (FALSE); 159 } 160 map = &curproc->p_vmspace->vm_map; 161 vm_map_lock_read(map); 162 /* 163 * We save the map hint, and restore it. Useracc appears to distort 164 * the map hint unnecessarily. 165 */ 166 save_hint = map->hint; 167 rv = vm_map_check_protection(map, 168 trunc_page((vm_offset_t)addr), round_page((vm_offset_t)addr + len), prot); 169 map->hint = save_hint; 170 vm_map_unlock_read(map); 171 172 return (rv == TRUE); 173 } 174 175 void 176 vslock(addr, len) 177 caddr_t addr; 178 u_int len; 179 { 180 vm_map_pageable(&curproc->p_vmspace->vm_map, trunc_page((vm_offset_t)addr), 181 round_page((vm_offset_t)addr + len), FALSE); 182 } 183 184 void 185 vsunlock(addr, len, dirtied) 186 caddr_t addr; 187 u_int len; 188 int dirtied; 189 { 190 #ifdef lint 191 dirtied++; 192 #endif /* lint */ 193 vm_map_pageable(&curproc->p_vmspace->vm_map, trunc_page((vm_offset_t)addr), 194 round_page((vm_offset_t)addr + len), TRUE); 195 } 196 197 /* 198 * Implement fork's actions on an address space. 199 * Here we arrange for the address space to be copied or referenced, 200 * allocate a user struct (pcb and kernel stack), then call the 201 * machine-dependent layer to fill those in and make the new process 202 * ready to run. The new process is set up so that it returns directly 203 * to user mode to avoid stack copying and relocation problems. 204 */ 205 void 206 vm_fork(p1, p2, flags) 207 register struct proc *p1, *p2; 208 int flags; 209 { 210 register struct user *up; 211 212 if (flags & RFMEM) { 213 p2->p_vmspace = p1->p_vmspace; 214 p1->p_vmspace->vm_refcnt++; 215 } 216 217 while (vm_page_count_severe()) { 218 VM_WAIT; 219 } 220 221 if ((flags & RFMEM) == 0) { 222 p2->p_vmspace = vmspace_fork(p1->p_vmspace); 223 224 pmap_pinit2(vmspace_pmap(p2->p_vmspace)); 225 226 if (p1->p_vmspace->vm_shm) 227 shmfork(p1, p2); 228 } 229 230 pmap_new_proc(p2); 231 232 up = p2->p_addr; 233 234 /* 235 * p_stats currently points at fields in the user struct 236 * but not at &u, instead at p_addr. Copy parts of 237 * p_stats; zero the rest of p_stats (statistics). 238 * 239 * If procsig->ps_refcnt is 1 and p2->p_sigacts is NULL we dont' need 240 * to share sigacts, so we use the up->u_sigacts. 241 */ 242 p2->p_stats = &up->u_stats; 243 if (p2->p_sigacts == NULL) { 244 if (p2->p_procsig->ps_refcnt != 1) 245 printf ("PID:%d NULL sigacts with refcnt not 1!\n",p2->p_pid); 246 p2->p_sigacts = &up->u_sigacts; 247 up->u_sigacts = *p1->p_sigacts; 248 } 249 250 bzero(&up->u_stats.pstat_startzero, 251 (unsigned) ((caddr_t) &up->u_stats.pstat_endzero - 252 (caddr_t) &up->u_stats.pstat_startzero)); 253 bcopy(&p1->p_stats->pstat_startcopy, &up->u_stats.pstat_startcopy, 254 ((caddr_t) &up->u_stats.pstat_endcopy - 255 (caddr_t) &up->u_stats.pstat_startcopy)); 256 257 258 /* 259 * cpu_fork will copy and update the pcb, set up the kernel stack, 260 * and make the child ready to run. 261 */ 262 cpu_fork(p1, p2); 263 } 264 265 /* 266 * Set default limits for VM system. 267 * Called for proc 0, and then inherited by all others. 268 * 269 * XXX should probably act directly on proc0. 270 */ 271 static void 272 vm_init_limits(udata) 273 void *udata; 274 { 275 register struct proc *p = udata; 276 int rss_limit; 277 278 /* 279 * Set up the initial limits on process VM. Set the maximum resident 280 * set size to be half of (reasonably) available memory. Since this 281 * is a soft limit, it comes into effect only when the system is out 282 * of memory - half of main memory helps to favor smaller processes, 283 * and reduces thrashing of the object cache. 284 */ 285 p->p_rlimit[RLIMIT_STACK].rlim_cur = DFLSSIZ; 286 p->p_rlimit[RLIMIT_STACK].rlim_max = MAXSSIZ; 287 p->p_rlimit[RLIMIT_DATA].rlim_cur = DFLDSIZ; 288 p->p_rlimit[RLIMIT_DATA].rlim_max = MAXDSIZ; 289 /* limit the limit to no less than 2MB */ 290 rss_limit = max(cnt.v_free_count, 512); 291 p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(rss_limit); 292 p->p_rlimit[RLIMIT_RSS].rlim_max = RLIM_INFINITY; 293 } 294 295 void 296 faultin(p) 297 struct proc *p; 298 { 299 int s; 300 301 if ((p->p_flag & P_INMEM) == 0) { 302 303 ++p->p_lock; 304 305 pmap_swapin_proc(p); 306 307 s = splhigh(); 308 309 if (p->p_stat == SRUN) 310 setrunqueue(p); 311 312 p->p_flag |= P_INMEM; 313 314 /* undo the effect of setting SLOCK above */ 315 --p->p_lock; 316 splx(s); 317 318 } 319 } 320 321 /* 322 * This swapin algorithm attempts to swap-in processes only if there 323 * is enough space for them. Of course, if a process waits for a long 324 * time, it will be swapped in anyway. 325 */ 326 /* ARGSUSED*/ 327 static void 328 scheduler(dummy) 329 void *dummy; 330 { 331 register struct proc *p; 332 register int pri; 333 struct proc *pp; 334 int ppri; 335 336 loop: 337 if (vm_page_count_min()) { 338 VM_WAIT; 339 goto loop; 340 } 341 342 pp = NULL; 343 ppri = INT_MIN; 344 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { 345 if (p->p_stat == SRUN && 346 (p->p_flag & (P_INMEM | P_SWAPPING)) == 0) { 347 348 pri = p->p_swtime + p->p_slptime; 349 if ((p->p_flag & P_SWAPINREQ) == 0) { 350 pri -= p->p_nice * 8; 351 } 352 353 /* 354 * if this process is higher priority and there is 355 * enough space, then select this process instead of 356 * the previous selection. 357 */ 358 if (pri > ppri) { 359 pp = p; 360 ppri = pri; 361 } 362 } 363 } 364 365 /* 366 * Nothing to do, back to sleep. 367 */ 368 if ((p = pp) == NULL) { 369 tsleep(&proc0, PVM, "sched", 0); 370 goto loop; 371 } 372 p->p_flag &= ~P_SWAPINREQ; 373 374 /* 375 * We would like to bring someone in. (only if there is space). 376 */ 377 faultin(p); 378 p->p_swtime = 0; 379 goto loop; 380 } 381 382 #ifndef NO_SWAPPING 383 384 #define swappable(p) \ 385 (((p)->p_lock == 0) && \ 386 ((p)->p_flag & (P_TRACED|P_SYSTEM|P_INMEM|P_WEXIT|P_SWAPPING)) == P_INMEM) 387 388 389 /* 390 * Swap_idle_threshold1 is the guaranteed swapped in time for a process 391 */ 392 static int swap_idle_threshold1 = 2; 393 SYSCTL_INT(_vm, OID_AUTO, swap_idle_threshold1, 394 CTLFLAG_RW, &swap_idle_threshold1, 0, ""); 395 396 /* 397 * Swap_idle_threshold2 is the time that a process can be idle before 398 * it will be swapped out, if idle swapping is enabled. 399 */ 400 static int swap_idle_threshold2 = 10; 401 SYSCTL_INT(_vm, OID_AUTO, swap_idle_threshold2, 402 CTLFLAG_RW, &swap_idle_threshold2, 0, ""); 403 404 /* 405 * Swapout is driven by the pageout daemon. Very simple, we find eligible 406 * procs and unwire their u-areas. We try to always "swap" at least one 407 * process in case we need the room for a swapin. 408 * If any procs have been sleeping/stopped for at least maxslp seconds, 409 * they are swapped. Else, we swap the longest-sleeping or stopped process, 410 * if any, otherwise the longest-resident process. 411 */ 412 void 413 swapout_procs(action) 414 int action; 415 { 416 register struct proc *p; 417 struct proc *outp, *outp2; 418 int outpri, outpri2; 419 int didswap = 0; 420 421 outp = outp2 = NULL; 422 outpri = outpri2 = INT_MIN; 423 retry: 424 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { 425 struct vmspace *vm; 426 if (!swappable(p)) 427 continue; 428 429 vm = p->p_vmspace; 430 431 switch (p->p_stat) { 432 default: 433 continue; 434 435 case SSLEEP: 436 case SSTOP: 437 /* 438 * do not swapout a realtime process 439 */ 440 if (RTP_PRIO_IS_REALTIME(p->p_rtprio.type)) 441 continue; 442 443 /* 444 * Do not swapout a process waiting on a critical 445 * event of some kind. Also guarantee swap_idle_threshold1 446 * time in memory. 447 */ 448 if (((p->p_priority & 0x7f) < PSOCK) || 449 (p->p_slptime < swap_idle_threshold1)) 450 continue; 451 452 /* 453 * If the system is under memory stress, or if we are swapping 454 * idle processes >= swap_idle_threshold2, then swap the process 455 * out. 456 */ 457 if (((action & VM_SWAP_NORMAL) == 0) && 458 (((action & VM_SWAP_IDLE) == 0) || 459 (p->p_slptime < swap_idle_threshold2))) 460 continue; 461 462 ++vm->vm_refcnt; 463 /* 464 * do not swapout a process that is waiting for VM 465 * data structures there is a possible deadlock. 466 */ 467 if (lockmgr(&vm->vm_map.lock, 468 LK_EXCLUSIVE | LK_NOWAIT, 469 (void *)0, curproc)) { 470 vmspace_free(vm); 471 continue; 472 } 473 vm_map_unlock(&vm->vm_map); 474 /* 475 * If the process has been asleep for awhile and had 476 * most of its pages taken away already, swap it out. 477 */ 478 if ((action & VM_SWAP_NORMAL) || 479 ((action & VM_SWAP_IDLE) && 480 (p->p_slptime > swap_idle_threshold2))) { 481 swapout(p); 482 vmspace_free(vm); 483 didswap++; 484 goto retry; 485 } 486 } 487 } 488 /* 489 * If we swapped something out, and another process needed memory, 490 * then wakeup the sched process. 491 */ 492 if (didswap) 493 wakeup(&proc0); 494 } 495 496 static void 497 swapout(p) 498 register struct proc *p; 499 { 500 501 #if defined(SWAP_DEBUG) 502 printf("swapping out %d\n", p->p_pid); 503 #endif 504 ++p->p_stats->p_ru.ru_nswap; 505 /* 506 * remember the process resident count 507 */ 508 p->p_vmspace->vm_swrss = vmspace_resident_count(p->p_vmspace); 509 510 (void) splhigh(); 511 p->p_flag &= ~P_INMEM; 512 p->p_flag |= P_SWAPPING; 513 if (p->p_stat == SRUN) 514 remrunqueue(p); 515 (void) spl0(); 516 517 pmap_swapout_proc(p); 518 519 p->p_flag &= ~P_SWAPPING; 520 p->p_swtime = 0; 521 } 522 #endif /* !NO_SWAPPING */ 523