1 /* 2 * Copyright (c) 1997, 1998 John S. Dyson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice immediately at the beginning of the file, without modification, 10 * this list of conditions, and the following disclaimer. 11 * 2. Absolutely no warranty of function or purpose is made by the author 12 * John S. Dyson. 13 * 14 * $FreeBSD: src/sys/vm/vm_zone.c,v 1.30.2.6 2002/10/10 19:50:16 dillon Exp $ 15 * $DragonFly: src/sys/vm/vm_zone.c,v 1.17 2004/10/26 04:33:11 dillon Exp $ 16 */ 17 18 #include <sys/param.h> 19 #include <sys/systm.h> 20 #include <sys/kernel.h> 21 #include <sys/lock.h> 22 #include <sys/malloc.h> 23 #include <sys/sysctl.h> 24 #include <sys/vmmeter.h> 25 26 #include <vm/vm.h> 27 #include <vm/vm_object.h> 28 #include <vm/vm_page.h> 29 #include <vm/vm_map.h> 30 #include <vm/vm_kern.h> 31 #include <vm/vm_extern.h> 32 #include <vm/vm_zone.h> 33 34 static MALLOC_DEFINE(M_ZONE, "ZONE", "Zone header"); 35 36 #define ZONE_ERROR_INVALID 0 37 #define ZONE_ERROR_NOTFREE 1 38 #define ZONE_ERROR_ALREADYFREE 2 39 40 #define ZONE_ROUNDING 32 41 42 #define ZENTRY_FREE 0x12342378 43 44 static void *zget(vm_zone_t z); 45 46 /* 47 * Return an item from the specified zone. This function is interrupt/MP 48 * thread safe, but might block. 49 */ 50 void * 51 zalloc(vm_zone_t z) 52 { 53 void *item; 54 lwkt_tokref ilock; 55 56 #ifdef INVARIANTS 57 if (z == NULL) 58 zerror(ZONE_ERROR_INVALID); 59 #endif 60 lwkt_gettoken(&ilock, &z->zlock); 61 if (z->zfreecnt <= z->zfreemin) { 62 item = zget(z); 63 /* 64 * PANICFAIL allows the caller to assume that the zalloc() 65 * will always succeed. If it doesn't, we panic here. 66 */ 67 if (item == NULL && (z->zflags & ZONE_PANICFAIL)) 68 panic("zalloc(%s) failed", z->zname); 69 } else { 70 item = z->zitems; 71 #ifdef INVARIANTS 72 KASSERT(item != NULL, ("zitems unexpectedly NULL")); 73 if (((void **) item)[1] != (void *) ZENTRY_FREE) 74 zerror(ZONE_ERROR_NOTFREE); 75 ((void **) item)[1] = 0; 76 #endif 77 z->zitems = ((void **) item)[0]; 78 z->zfreecnt--; 79 z->znalloc++; 80 } 81 lwkt_reltoken(&ilock); 82 return item; 83 } 84 85 /* 86 * Free an item to the specified zone. This function is interrupt/MP 87 * thread safe, but might block. 88 */ 89 void 90 zfree(vm_zone_t z, void *item) 91 { 92 lwkt_tokref ilock; 93 94 lwkt_gettoken(&ilock, &z->zlock); 95 ((void **) item)[0] = z->zitems; 96 #ifdef INVARIANTS 97 if (((void **) item)[1] == (void *) ZENTRY_FREE) 98 zerror(ZONE_ERROR_ALREADYFREE); 99 ((void **) item)[1] = (void *) ZENTRY_FREE; 100 #endif 101 z->zitems = item; 102 z->zfreecnt++; 103 lwkt_reltoken(&ilock); 104 } 105 106 /* 107 * This file comprises a very simple zone allocator. This is used 108 * in lieu of the malloc allocator, where needed or more optimal. 109 * 110 * Note that the initial implementation of this had coloring, and 111 * absolutely no improvement (actually perf degradation) occurred. 112 * 113 * Note also that the zones are type stable. The only restriction is 114 * that the first two longwords of a data structure can be changed 115 * between allocations. Any data that must be stable between allocations 116 * must reside in areas after the first two longwords. 117 * 118 * zinitna, zinit, zbootinit are the initialization routines. 119 * zalloc, zfree, are the allocation/free routines. 120 */ 121 122 static struct vm_zone *zlist; 123 static int sysctl_vm_zone(SYSCTL_HANDLER_ARGS); 124 static int zone_kmem_pages, zone_kern_pages, zone_kmem_kvaspace; 125 126 /* 127 * Create a zone, but don't allocate the zone structure. If the 128 * zone had been previously created by the zone boot code, initialize 129 * various parts of the zone code. 130 * 131 * If waits are not allowed during allocation (e.g. during interrupt 132 * code), a-priori allocate the kernel virtual space, and allocate 133 * only pages when needed. 134 * 135 * Arguments: 136 * z pointer to zone structure. 137 * obj pointer to VM object (opt). 138 * name name of zone. 139 * size size of zone entries. 140 * nentries number of zone entries allocated (only ZONE_INTERRUPT.) 141 * flags ZONE_INTERRUPT -- items can be allocated at interrupt time. 142 * zalloc number of pages allocated when memory is needed. 143 * 144 * Note that when using ZONE_INTERRUPT, the size of the zone is limited 145 * by the nentries argument. The size of the memory allocatable is 146 * unlimited if ZONE_INTERRUPT is not set. 147 * 148 */ 149 int 150 zinitna(vm_zone_t z, vm_object_t obj, char *name, int size, 151 int nentries, int flags, int zalloc) 152 { 153 int totsize; 154 155 if ((z->zflags & ZONE_BOOT) == 0) { 156 z->zsize = (size + ZONE_ROUNDING - 1) & ~(ZONE_ROUNDING - 1); 157 lwkt_token_init(&z->zlock); 158 z->zfreecnt = 0; 159 z->ztotal = 0; 160 z->zmax = 0; 161 z->zname = name; 162 z->znalloc = 0; 163 z->zitems = NULL; 164 165 z->znext = zlist; 166 zlist = z; 167 } 168 169 z->zflags |= flags; 170 171 /* 172 * If we cannot wait, allocate KVA space up front, and we will fill 173 * in pages as needed. This is particularly required when creating 174 * an allocation space for map entries in kernel_map, because we 175 * do not want to go into a recursion deadlock with 176 * vm_map_entry_reserve(). 177 */ 178 if (z->zflags & ZONE_INTERRUPT) { 179 180 totsize = round_page(z->zsize * nentries); 181 zone_kmem_kvaspace += totsize; 182 183 z->zkva = kmem_alloc_pageable(kernel_map, totsize); 184 if (z->zkva == 0) { 185 zlist = z->znext; 186 return 0; 187 } 188 189 z->zpagemax = totsize / PAGE_SIZE; 190 if (obj == NULL) { 191 z->zobj = vm_object_allocate(OBJT_DEFAULT, z->zpagemax); 192 } else { 193 z->zobj = obj; 194 _vm_object_allocate(OBJT_DEFAULT, z->zpagemax, obj); 195 } 196 z->zallocflag = VM_ALLOC_SYSTEM | VM_ALLOC_INTERRUPT; 197 z->zmax += nentries; 198 } else { 199 z->zallocflag = VM_ALLOC_NORMAL | VM_ALLOC_SYSTEM; 200 z->zmax = 0; 201 } 202 203 204 if (z->zsize > PAGE_SIZE) 205 z->zfreemin = 1; 206 else 207 z->zfreemin = PAGE_SIZE / z->zsize; 208 209 z->zpagecount = 0; 210 if (zalloc) 211 z->zalloc = zalloc; 212 else 213 z->zalloc = 1; 214 215 return 1; 216 } 217 218 /* 219 * Subroutine same as zinitna, except zone data structure is allocated 220 * automatically by malloc. This routine should normally be used, except 221 * in certain tricky startup conditions in the VM system -- then 222 * zbootinit and zinitna can be used. Zinit is the standard zone 223 * initialization call. 224 */ 225 vm_zone_t 226 zinit(char *name, int size, int nentries, int flags, int zalloc) 227 { 228 vm_zone_t z; 229 230 z = (vm_zone_t) malloc(sizeof (struct vm_zone), M_ZONE, M_NOWAIT); 231 if (z == NULL) 232 return NULL; 233 234 z->zflags = 0; 235 if (zinitna(z, NULL, name, size, nentries, flags, zalloc) == 0) { 236 free(z, M_ZONE); 237 return NULL; 238 } 239 240 return z; 241 } 242 243 /* 244 * Initialize a zone before the system is fully up. This routine should 245 * only be called before full VM startup. 246 */ 247 void 248 zbootinit(vm_zone_t z, char *name, int size, void *item, int nitems) 249 { 250 int i; 251 252 z->zname = name; 253 z->zsize = size; 254 z->zpagemax = 0; 255 z->zobj = NULL; 256 z->zflags = ZONE_BOOT; 257 z->zfreemin = 0; 258 z->zallocflag = 0; 259 z->zpagecount = 0; 260 z->zalloc = 0; 261 z->znalloc = 0; 262 lwkt_token_init(&z->zlock); 263 264 bzero(item, nitems * z->zsize); 265 z->zitems = NULL; 266 for (i = 0; i < nitems; i++) { 267 ((void **) item)[0] = z->zitems; 268 #ifdef INVARIANTS 269 ((void **) item)[1] = (void *) ZENTRY_FREE; 270 #endif 271 z->zitems = item; 272 item = (uint8_t *)item + z->zsize; 273 } 274 z->zfreecnt = nitems; 275 z->zmax = nitems; 276 z->ztotal = nitems; 277 278 if (zlist == 0) { 279 zlist = z; 280 } else { 281 z->znext = zlist; 282 zlist = z; 283 } 284 } 285 286 /* 287 * void *zalloc(vm_zone_t zone) -- 288 * Returns an item from a specified zone. May not be called from a 289 * FAST interrupt or IPI function. 290 * 291 * void zfree(vm_zone_t zone, void *item) -- 292 * Frees an item back to a specified zone. May not be called from a 293 * FAST interrupt or IPI function. 294 */ 295 296 /* 297 * Internal zone routine. Not to be called from external (non vm_zone) code. 298 */ 299 static void * 300 zget(vm_zone_t z) 301 { 302 int i; 303 vm_page_t m; 304 int nitems, nbytes; 305 void *item; 306 307 if (z == NULL) 308 panic("zget: null zone"); 309 310 if (z->zflags & ZONE_INTERRUPT) { 311 /* 312 * Interrupt zones do not mess with the kernel_map, they 313 * simply populate an existing mapping. 314 */ 315 nbytes = z->zpagecount * PAGE_SIZE; 316 nbytes -= nbytes % z->zsize; 317 item = (char *) z->zkva + nbytes; 318 for (i = 0; ((i < z->zalloc) && (z->zpagecount < z->zpagemax)); 319 i++) { 320 vm_offset_t zkva; 321 322 m = vm_page_alloc(z->zobj, z->zpagecount, 323 z->zallocflag); 324 /* note: z might be modified due to blocking */ 325 if (m == NULL) 326 break; 327 328 zkva = z->zkva + z->zpagecount * PAGE_SIZE; 329 pmap_kenter(zkva, VM_PAGE_TO_PHYS(m)); /* YYY */ 330 bzero((caddr_t) zkva, PAGE_SIZE); 331 z->zpagecount++; 332 zone_kmem_pages++; 333 vmstats.v_wire_count++; 334 } 335 nitems = ((z->zpagecount * PAGE_SIZE) - nbytes) / z->zsize; 336 } else if (z->zflags & ZONE_SPECIAL) { 337 /* 338 * The special zone is the one used for vm_map_entry_t's. 339 * We have to avoid an infinite recursion in 340 * vm_map_entry_reserve() by using vm_map_entry_kreserve() 341 * instead. The map entries are pre-reserved by the kernel 342 * by vm_map_entry_reserve_cpu_init(). 343 */ 344 nbytes = z->zalloc * PAGE_SIZE; 345 346 item = (void *)kmem_alloc3(kernel_map, nbytes, KM_KRESERVE); 347 348 /* note: z might be modified due to blocking */ 349 if (item != NULL) { 350 zone_kern_pages += z->zalloc; 351 bzero(item, nbytes); 352 } else { 353 nbytes = 0; 354 } 355 nitems = nbytes / z->zsize; 356 } else { 357 /* 358 * Otherwise allocate KVA from the kernel_map. 359 */ 360 nbytes = z->zalloc * PAGE_SIZE; 361 362 item = (void *)kmem_alloc3(kernel_map, nbytes, 0); 363 364 /* note: z might be modified due to blocking */ 365 if (item != NULL) { 366 zone_kern_pages += z->zalloc; 367 bzero(item, nbytes); 368 } else { 369 nbytes = 0; 370 } 371 nitems = nbytes / z->zsize; 372 } 373 z->ztotal += nitems; 374 375 /* 376 * Save one for immediate allocation 377 */ 378 if (nitems != 0) { 379 nitems -= 1; 380 for (i = 0; i < nitems; i++) { 381 ((void **) item)[0] = z->zitems; 382 #ifdef INVARIANTS 383 ((void **) item)[1] = (void *) ZENTRY_FREE; 384 #endif 385 z->zitems = item; 386 item = (uint8_t *)item + z->zsize; 387 } 388 z->zfreecnt += nitems; 389 z->znalloc++; 390 } else if (z->zfreecnt > 0) { 391 item = z->zitems; 392 z->zitems = ((void **) item)[0]; 393 #ifdef INVARIANTS 394 if (((void **) item)[1] != (void *) ZENTRY_FREE) 395 zerror(ZONE_ERROR_NOTFREE); 396 ((void **) item)[1] = 0; 397 #endif 398 z->zfreecnt--; 399 z->znalloc++; 400 } else { 401 item = NULL; 402 } 403 404 /* 405 * A special zone may have used a kernel-reserved vm_map_entry. If 406 * so we have to be sure to recover our reserve so we don't run out. 407 * We will panic if we run out. 408 */ 409 if (z->zflags & ZONE_SPECIAL) 410 vm_map_entry_reserve(0); 411 412 return item; 413 } 414 415 static int 416 sysctl_vm_zone(SYSCTL_HANDLER_ARGS) 417 { 418 int error=0; 419 vm_zone_t curzone, nextzone; 420 char tmpbuf[128]; 421 char tmpname[14]; 422 423 snprintf(tmpbuf, sizeof(tmpbuf), 424 "\nITEM SIZE LIMIT USED FREE REQUESTS\n"); 425 error = SYSCTL_OUT(req, tmpbuf, strlen(tmpbuf)); 426 if (error) 427 return (error); 428 429 for (curzone = zlist; curzone; curzone = nextzone) { 430 int i; 431 int len; 432 int offset; 433 434 nextzone = curzone->znext; 435 len = strlen(curzone->zname); 436 if (len >= (sizeof(tmpname) - 1)) 437 len = (sizeof(tmpname) - 1); 438 for(i = 0; i < sizeof(tmpname) - 1; i++) 439 tmpname[i] = ' '; 440 tmpname[i] = 0; 441 memcpy(tmpname, curzone->zname, len); 442 tmpname[len] = ':'; 443 offset = 0; 444 if (curzone == zlist) { 445 offset = 1; 446 tmpbuf[0] = '\n'; 447 } 448 449 snprintf(tmpbuf + offset, sizeof(tmpbuf) - offset, 450 "%s %6.6u, %8.8u, %6.6u, %6.6u, %8.8u\n", 451 tmpname, curzone->zsize, curzone->zmax, 452 (curzone->ztotal - curzone->zfreecnt), 453 curzone->zfreecnt, curzone->znalloc); 454 455 len = strlen((char *)tmpbuf); 456 if (nextzone == NULL) 457 tmpbuf[len - 1] = 0; 458 459 error = SYSCTL_OUT(req, tmpbuf, len); 460 461 if (error) 462 return (error); 463 } 464 return (0); 465 } 466 467 #if defined(INVARIANTS) 468 void 469 zerror(int error) 470 { 471 char *msg; 472 473 switch (error) { 474 case ZONE_ERROR_INVALID: 475 msg = "zone: invalid zone"; 476 break; 477 case ZONE_ERROR_NOTFREE: 478 msg = "zone: entry not free"; 479 break; 480 case ZONE_ERROR_ALREADYFREE: 481 msg = "zone: freeing free entry"; 482 break; 483 default: 484 msg = "zone: invalid error"; 485 break; 486 } 487 panic(msg); 488 } 489 #endif 490 491 SYSCTL_OID(_vm, OID_AUTO, zone, CTLTYPE_STRING|CTLFLAG_RD, \ 492 NULL, 0, sysctl_vm_zone, "A", "Zone Info"); 493 494 SYSCTL_INT(_vm, OID_AUTO, zone_kmem_pages, 495 CTLFLAG_RD, &zone_kmem_pages, 0, "Number of interrupt safe pages allocated by zone"); 496 SYSCTL_INT(_vm, OID_AUTO, zone_kmem_kvaspace, 497 CTLFLAG_RD, &zone_kmem_kvaspace, 0, "KVA space allocated by zone"); 498 SYSCTL_INT(_vm, OID_AUTO, zone_kern_pages, 499 CTLFLAG_RD, &zone_kern_pages, 0, "Number of non-interrupt safe pages allocated by zone"); 500