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 1.24 2007/01/12 03:05:49 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 #include <sys/spinlock2.h> /* XXX */ 34 35 static MALLOC_DEFINE(M_ZONE, "ZONE", "Zone header"); 36 37 #define ZONE_ERROR_INVALID 0 38 #define ZONE_ERROR_NOTFREE 1 39 #define ZONE_ERROR_ALREADYFREE 2 40 41 #define ZONE_ROUNDING 32 42 43 #define ZENTRY_FREE 0x12342378 44 45 static void *zget(vm_zone_t z); 46 47 /* 48 * Return an item from the specified zone. This function is interrupt/MP 49 * thread safe and is non-blocking for ZONE_INTERRUPT zones. 50 */ 51 void * 52 zalloc(vm_zone_t z) 53 { 54 void *item; 55 56 #ifdef INVARIANTS 57 if (z == NULL) 58 zerror(ZONE_ERROR_INVALID); 59 #endif 60 spin_lock_wr(&z->zlock); 61 if (z->zfreecnt > z->zfreemin) { 62 item = z->zitems; 63 #ifdef INVARIANTS 64 KASSERT(item != NULL, ("zitems unexpectedly NULL")); 65 if (((void **) item)[1] != (void *) ZENTRY_FREE) 66 zerror(ZONE_ERROR_NOTFREE); 67 ((void **) item)[1] = 0; 68 #endif 69 z->zitems = ((void **) item)[0]; 70 z->zfreecnt--; 71 z->znalloc++; 72 spin_unlock_wr(&z->zlock); 73 } else { 74 spin_unlock_wr(&z->zlock); 75 item = zget(z); 76 /* 77 * PANICFAIL allows the caller to assume that the zalloc() 78 * will always succeed. If it doesn't, we panic here. 79 */ 80 if (item == NULL && (z->zflags & ZONE_PANICFAIL)) 81 panic("zalloc(%s) failed", z->zname); 82 } 83 return item; 84 } 85 86 /* 87 * Free an item to the specified zone. This function is interrupt/MP 88 * thread safe and is non-blocking. 89 */ 90 void 91 zfree(vm_zone_t z, void *item) 92 { 93 94 spin_lock_wr(&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 spin_unlock_wr(&z->zlock); 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 struct vm_zone *zlist; /* exported to vmstat */ 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 spin_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 totsize = round_page(z->zsize * nentries); 180 zone_kmem_kvaspace += totsize; 181 182 z->zkva = kmem_alloc_pageable(&kernel_map, totsize); 183 if (z->zkva == 0) { 184 zlist = z->znext; 185 return 0; 186 } 187 188 z->zpagemax = totsize / PAGE_SIZE; 189 if (obj == NULL) { 190 z->zobj = vm_object_allocate(OBJT_DEFAULT, z->zpagemax); 191 } else { 192 z->zobj = obj; 193 _vm_object_allocate(OBJT_DEFAULT, z->zpagemax, obj); 194 } 195 z->zallocflag = VM_ALLOC_SYSTEM | VM_ALLOC_INTERRUPT; 196 z->zmax += nentries; 197 } else { 198 z->zallocflag = VM_ALLOC_NORMAL | VM_ALLOC_SYSTEM; 199 z->zmax = 0; 200 } 201 202 203 if (z->zsize > PAGE_SIZE) 204 z->zfreemin = 1; 205 else 206 z->zfreemin = PAGE_SIZE / z->zsize; 207 208 z->zpagecount = 0; 209 if (zalloc) 210 z->zalloc = zalloc; 211 else 212 z->zalloc = 1; 213 214 /* 215 * Populate the interrrupt zone at creation time rather than 216 * on first allocation, as this is a potentially long operation. 217 */ 218 if (z->zflags & ZONE_INTERRUPT) { 219 void *buf; 220 221 buf = zget(z); 222 zfree(z, buf); 223 } 224 225 return 1; 226 } 227 228 /* 229 * Subroutine same as zinitna, except zone data structure is allocated 230 * automatically by malloc. This routine should normally be used, except 231 * in certain tricky startup conditions in the VM system -- then 232 * zbootinit and zinitna can be used. Zinit is the standard zone 233 * initialization call. 234 */ 235 vm_zone_t 236 zinit(char *name, int size, int nentries, int flags, int zalloc) 237 { 238 vm_zone_t z; 239 240 z = (vm_zone_t) kmalloc(sizeof (struct vm_zone), M_ZONE, M_NOWAIT); 241 if (z == NULL) 242 return NULL; 243 244 z->zflags = 0; 245 if (zinitna(z, NULL, name, size, nentries, flags, zalloc) == 0) { 246 kfree(z, M_ZONE); 247 return NULL; 248 } 249 250 return z; 251 } 252 253 /* 254 * Initialize a zone before the system is fully up. This routine should 255 * only be called before full VM startup. 256 */ 257 void 258 zbootinit(vm_zone_t z, char *name, int size, void *item, int nitems) 259 { 260 int i; 261 262 z->zname = name; 263 z->zsize = size; 264 z->zpagemax = 0; 265 z->zobj = NULL; 266 z->zflags = ZONE_BOOT; 267 z->zfreemin = 0; 268 z->zallocflag = 0; 269 z->zpagecount = 0; 270 z->zalloc = 0; 271 z->znalloc = 0; 272 spin_init(&z->zlock); 273 274 bzero(item, nitems * z->zsize); 275 z->zitems = NULL; 276 for (i = 0; i < nitems; i++) { 277 ((void **) item)[0] = z->zitems; 278 #ifdef INVARIANTS 279 ((void **) item)[1] = (void *) ZENTRY_FREE; 280 #endif 281 z->zitems = item; 282 item = (uint8_t *)item + z->zsize; 283 } 284 z->zfreecnt = nitems; 285 z->zmax = nitems; 286 z->ztotal = nitems; 287 288 if (zlist == 0) { 289 zlist = z; 290 } else { 291 z->znext = zlist; 292 zlist = z; 293 } 294 } 295 296 /* 297 * void *zalloc(vm_zone_t zone) -- 298 * Returns an item from a specified zone. May not be called from a 299 * FAST interrupt or IPI function. 300 * 301 * void zfree(vm_zone_t zone, void *item) -- 302 * Frees an item back to a specified zone. May not be called from a 303 * FAST interrupt or IPI function. 304 */ 305 306 /* 307 * Internal zone routine. Not to be called from external (non vm_zone) code. 308 */ 309 static void * 310 zget(vm_zone_t z) 311 { 312 int i; 313 vm_page_t m; 314 int nitems, nbytes; 315 void *item; 316 317 if (z == NULL) 318 panic("zget: null zone"); 319 320 if (z->zflags & ZONE_INTERRUPT) { 321 /* 322 * Interrupt zones do not mess with the kernel_map, they 323 * simply populate an existing mapping. 324 */ 325 nbytes = z->zpagecount * PAGE_SIZE; 326 nbytes -= nbytes % z->zsize; 327 item = (char *) z->zkva + nbytes; 328 for (i = 0; ((i < z->zalloc) && (z->zpagecount < z->zpagemax)); 329 i++) { 330 vm_offset_t zkva; 331 332 m = vm_page_alloc(z->zobj, z->zpagecount, 333 z->zallocflag); 334 /* note: z might be modified due to blocking */ 335 if (m == NULL) 336 break; 337 338 zkva = z->zkva + z->zpagecount * PAGE_SIZE; 339 pmap_kenter(zkva, VM_PAGE_TO_PHYS(m)); /* YYY */ 340 bzero((void *)zkva, PAGE_SIZE); 341 z->zpagecount++; 342 zone_kmem_pages++; 343 vmstats.v_wire_count++; 344 } 345 nitems = ((z->zpagecount * PAGE_SIZE) - nbytes) / z->zsize; 346 } else if (z->zflags & ZONE_SPECIAL) { 347 /* 348 * The special zone is the one used for vm_map_entry_t's. 349 * We have to avoid an infinite recursion in 350 * vm_map_entry_reserve() by using vm_map_entry_kreserve() 351 * instead. The map entries are pre-reserved by the kernel 352 * by vm_map_entry_reserve_cpu_init(). 353 */ 354 nbytes = z->zalloc * PAGE_SIZE; 355 356 item = (void *)kmem_alloc3(&kernel_map, nbytes, KM_KRESERVE); 357 358 /* note: z might be modified due to blocking */ 359 if (item != NULL) { 360 zone_kern_pages += z->zalloc; /* not MP-safe XXX */ 361 bzero(item, nbytes); 362 } else { 363 nbytes = 0; 364 } 365 nitems = nbytes / z->zsize; 366 } else { 367 /* 368 * Otherwise allocate KVA from the kernel_map. 369 */ 370 nbytes = z->zalloc * PAGE_SIZE; 371 372 item = (void *)kmem_alloc3(&kernel_map, nbytes, 0); 373 374 /* note: z might be modified due to blocking */ 375 if (item != NULL) { 376 zone_kern_pages += z->zalloc; /* not MP-safe XXX */ 377 bzero(item, nbytes); 378 } else { 379 nbytes = 0; 380 } 381 nitems = nbytes / z->zsize; 382 } 383 384 spin_lock_wr(&z->zlock); 385 z->ztotal += nitems; 386 /* 387 * Save one for immediate allocation 388 */ 389 if (nitems != 0) { 390 nitems -= 1; 391 for (i = 0; i < nitems; i++) { 392 ((void **) item)[0] = z->zitems; 393 #ifdef INVARIANTS 394 ((void **) item)[1] = (void *) ZENTRY_FREE; 395 #endif 396 z->zitems = item; 397 item = (uint8_t *)item + z->zsize; 398 } 399 z->zfreecnt += nitems; 400 z->znalloc++; 401 } else if (z->zfreecnt > 0) { 402 item = z->zitems; 403 z->zitems = ((void **) item)[0]; 404 #ifdef INVARIANTS 405 if (((void **) item)[1] != (void *) ZENTRY_FREE) 406 zerror(ZONE_ERROR_NOTFREE); 407 ((void **) item)[1] = 0; 408 #endif 409 z->zfreecnt--; 410 z->znalloc++; 411 } else { 412 item = NULL; 413 } 414 spin_unlock_wr(&z->zlock); 415 416 /* 417 * A special zone may have used a kernel-reserved vm_map_entry. If 418 * so we have to be sure to recover our reserve so we don't run out. 419 * We will panic if we run out. 420 */ 421 if (z->zflags & ZONE_SPECIAL) 422 vm_map_entry_reserve(0); 423 424 return item; 425 } 426 427 static int 428 sysctl_vm_zone(SYSCTL_HANDLER_ARGS) 429 { 430 int error=0; 431 vm_zone_t curzone, nextzone; 432 char tmpbuf[128]; 433 char tmpname[14]; 434 435 ksnprintf(tmpbuf, sizeof(tmpbuf), 436 "\nITEM SIZE LIMIT USED FREE REQUESTS\n"); 437 error = SYSCTL_OUT(req, tmpbuf, strlen(tmpbuf)); 438 if (error) 439 return (error); 440 441 for (curzone = zlist; curzone; curzone = nextzone) { 442 int i; 443 int len; 444 int offset; 445 446 nextzone = curzone->znext; 447 len = strlen(curzone->zname); 448 if (len >= (sizeof(tmpname) - 1)) 449 len = (sizeof(tmpname) - 1); 450 for(i = 0; i < sizeof(tmpname) - 1; i++) 451 tmpname[i] = ' '; 452 tmpname[i] = 0; 453 memcpy(tmpname, curzone->zname, len); 454 tmpname[len] = ':'; 455 offset = 0; 456 if (curzone == zlist) { 457 offset = 1; 458 tmpbuf[0] = '\n'; 459 } 460 461 ksnprintf(tmpbuf + offset, sizeof(tmpbuf) - offset, 462 "%s %6.6u, %8.8u, %6.6u, %6.6u, %8.8u\n", 463 tmpname, curzone->zsize, curzone->zmax, 464 (curzone->ztotal - curzone->zfreecnt), 465 curzone->zfreecnt, curzone->znalloc); 466 467 len = strlen((char *)tmpbuf); 468 if (nextzone == NULL) 469 tmpbuf[len - 1] = 0; 470 471 error = SYSCTL_OUT(req, tmpbuf, len); 472 473 if (error) 474 return (error); 475 } 476 return (0); 477 } 478 479 #if defined(INVARIANTS) 480 void 481 zerror(int error) 482 { 483 char *msg; 484 485 switch (error) { 486 case ZONE_ERROR_INVALID: 487 msg = "zone: invalid zone"; 488 break; 489 case ZONE_ERROR_NOTFREE: 490 msg = "zone: entry not free"; 491 break; 492 case ZONE_ERROR_ALREADYFREE: 493 msg = "zone: freeing free entry"; 494 break; 495 default: 496 msg = "zone: invalid error"; 497 break; 498 } 499 panic(msg); 500 } 501 #endif 502 503 SYSCTL_OID(_vm, OID_AUTO, zone, CTLTYPE_STRING|CTLFLAG_RD, \ 504 NULL, 0, sysctl_vm_zone, "A", "Zone Info"); 505 506 SYSCTL_INT(_vm, OID_AUTO, zone_kmem_pages, 507 CTLFLAG_RD, &zone_kmem_pages, 0, "Number of interrupt safe pages allocated by zone"); 508 SYSCTL_INT(_vm, OID_AUTO, zone_kmem_kvaspace, 509 CTLFLAG_RD, &zone_kmem_kvaspace, 0, "KVA space allocated by zone"); 510 SYSCTL_INT(_vm, OID_AUTO, zone_kern_pages, 511 CTLFLAG_RD, &zone_kern_pages, 0, "Number of non-interrupt safe pages allocated by zone"); 512