| 1 | /* |
| 2 | * KERN_SLABALLOC.C - Kernel SLAB memory allocator |
| 3 | * |
| 4 | * Copyright (c) 2003,2004 The DragonFly Project. All rights reserved. |
| 5 | * |
| 6 | * This code is derived from software contributed to The DragonFly Project |
| 7 | * by Matthew Dillon <dillon@backplane.com> |
| 8 | * |
| 9 | * Redistribution and use in source and binary forms, with or without |
| 10 | * modification, are permitted provided that the following conditions |
| 11 | * are met: |
| 12 | * |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer. |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer in |
| 17 | * the documentation and/or other materials provided with the |
| 18 | * distribution. |
| 19 | * 3. Neither the name of The DragonFly Project nor the names of its |
| 20 | * contributors may be used to endorse or promote products derived |
| 21 | * from this software without specific, prior written permission. |
| 22 | * |
| 23 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 24 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 25 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| 26 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| 27 | * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 28 | * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| 29 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 30 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| 31 | * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| 32 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| 33 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 34 | * SUCH DAMAGE. |
| 35 | * |
| 36 | * $DragonFly: src/sys/kern/kern_slaballoc.c,v 1.46 2006/12/28 21:24:01 dillon Exp $ |
| 37 | * |
| 38 | * This module implements a slab allocator drop-in replacement for the |
| 39 | * kernel malloc(). |
| 40 | * |
| 41 | * A slab allocator reserves a ZONE for each chunk size, then lays the |
| 42 | * chunks out in an array within the zone. Allocation and deallocation |
| 43 | * is nearly instantanious, and fragmentation/overhead losses are limited |
| 44 | * to a fixed worst-case amount. |
| 45 | * |
| 46 | * The downside of this slab implementation is in the chunk size |
| 47 | * multiplied by the number of zones. ~80 zones * 128K = 10MB of VM per cpu. |
| 48 | * In a kernel implementation all this memory will be physical so |
| 49 | * the zone size is adjusted downward on machines with less physical |
| 50 | * memory. The upside is that overhead is bounded... this is the *worst* |
| 51 | * case overhead. |
| 52 | * |
| 53 | * Slab management is done on a per-cpu basis and no locking or mutexes |
| 54 | * are required, only a critical section. When one cpu frees memory |
| 55 | * belonging to another cpu's slab manager an asynchronous IPI message |
| 56 | * will be queued to execute the operation. In addition, both the |
| 57 | * high level slab allocator and the low level zone allocator optimize |
| 58 | * M_ZERO requests, and the slab allocator does not have to pre initialize |
| 59 | * the linked list of chunks. |
| 60 | * |
| 61 | * XXX Balancing is needed between cpus. Balance will be handled through |
| 62 | * asynchronous IPIs primarily by reassigning the z_Cpu ownership of chunks. |
| 63 | * |
| 64 | * XXX If we have to allocate a new zone and M_USE_RESERVE is set, use of |
| 65 | * the new zone should be restricted to M_USE_RESERVE requests only. |
| 66 | * |
| 67 | * Alloc Size Chunking Number of zones |
| 68 | * 0-127 8 16 |
| 69 | * 128-255 16 8 |
| 70 | * 256-511 32 8 |
| 71 | * 512-1023 64 8 |
| 72 | * 1024-2047 128 8 |
| 73 | * 2048-4095 256 8 |
| 74 | * 4096-8191 512 8 |
| 75 | * 8192-16383 1024 8 |
| 76 | * 16384-32767 2048 8 |
| 77 | * (if PAGE_SIZE is 4K the maximum zone allocation is 16383) |
| 78 | * |
| 79 | * Allocations >= ZoneLimit go directly to kmem. |
| 80 | * |
| 81 | * API REQUIREMENTS AND SIDE EFFECTS |
| 82 | * |
| 83 | * To operate as a drop-in replacement to the FreeBSD-4.x malloc() we |
| 84 | * have remained compatible with the following API requirements: |
| 85 | * |
| 86 | * + small power-of-2 sized allocations are power-of-2 aligned (kern_tty) |
| 87 | * + all power-of-2 sized allocations are power-of-2 aligned (twe) |
| 88 | * + malloc(0) is allowed and returns non-NULL (ahc driver) |
| 89 | * + ability to allocate arbitrarily large chunks of memory |
| 90 | */ |
| 91 | |
| 92 | #include "opt_vm.h" |
| 93 | |
| 94 | #include <sys/param.h> |
| 95 | #include <sys/systm.h> |
| 96 | #include <sys/kernel.h> |
| 97 | #include <sys/slaballoc.h> |
| 98 | #include <sys/mbuf.h> |
| 99 | #include <sys/vmmeter.h> |
| 100 | #include <sys/lock.h> |
| 101 | #include <sys/thread.h> |
| 102 | #include <sys/globaldata.h> |
| 103 | #include <sys/sysctl.h> |
| 104 | #include <sys/ktr.h> |
| 105 | |
| 106 | #include <vm/vm.h> |
| 107 | #include <vm/vm_param.h> |
| 108 | #include <vm/vm_kern.h> |
| 109 | #include <vm/vm_extern.h> |
| 110 | #include <vm/vm_object.h> |
| 111 | #include <vm/pmap.h> |
| 112 | #include <vm/vm_map.h> |
| 113 | #include <vm/vm_page.h> |
| 114 | #include <vm/vm_pageout.h> |
| 115 | |
| 116 | #include <machine/cpu.h> |
| 117 | |
| 118 | #include <sys/thread2.h> |
| 119 | |
| 120 | #define arysize(ary) (sizeof(ary)/sizeof((ary)[0])) |
| 121 | |
| 122 | #define MEMORY_STRING "ptr=%p type=%p size=%d flags=%04x" |
| 123 | #define MEMORY_ARG_SIZE (sizeof(void *) * 2 + sizeof(unsigned long) + \ |
| 124 | sizeof(int)) |
| 125 | |
| 126 | #if !defined(KTR_MEMORY) |
| 127 | #define KTR_MEMORY KTR_ALL |
| 128 | #endif |
| 129 | KTR_INFO_MASTER(memory); |
| 130 | KTR_INFO(KTR_MEMORY, memory, malloc, 0, MEMORY_STRING, MEMORY_ARG_SIZE); |
| 131 | KTR_INFO(KTR_MEMORY, memory, free_zero, 1, MEMORY_STRING, MEMORY_ARG_SIZE); |
| 132 | KTR_INFO(KTR_MEMORY, memory, free_ovsz, 2, MEMORY_STRING, MEMORY_ARG_SIZE); |
| 133 | KTR_INFO(KTR_MEMORY, memory, free_ovsz_delayed, 3, MEMORY_STRING, MEMORY_ARG_SIZE); |
| 134 | KTR_INFO(KTR_MEMORY, memory, free_chunk, 4, MEMORY_STRING, MEMORY_ARG_SIZE); |
| 135 | #ifdef SMP |
| 136 | KTR_INFO(KTR_MEMORY, memory, free_request, 5, MEMORY_STRING, MEMORY_ARG_SIZE); |
| 137 | KTR_INFO(KTR_MEMORY, memory, free_remote, 6, MEMORY_STRING, MEMORY_ARG_SIZE); |
| 138 | #endif |
| 139 | KTR_INFO(KTR_MEMORY, memory, malloc_beg, 0, "malloc begin", 0); |
| 140 | KTR_INFO(KTR_MEMORY, memory, free_beg, 0, "free begin", 0); |
| 141 | KTR_INFO(KTR_MEMORY, memory, free_end, 0, "free end", 0); |
| 142 | |
| 143 | #define logmemory(name, ptr, type, size, flags) \ |
| 144 | KTR_LOG(memory_ ## name, ptr, type, size, flags) |
| 145 | #define logmemory_quick(name) \ |
| 146 | KTR_LOG(memory_ ## name) |
| 147 | |
| 148 | /* |
| 149 | * Fixed globals (not per-cpu) |
| 150 | */ |
| 151 | static int ZoneSize; |
| 152 | static int ZoneLimit; |
| 153 | static int ZonePageCount; |
| 154 | static int ZoneMask; |
| 155 | static struct malloc_type *kmemstatistics; |
| 156 | static struct kmemusage *kmemusage; |
| 157 | static int32_t weirdary[16]; |
| 158 | |
| 159 | static void *kmem_slab_alloc(vm_size_t bytes, vm_offset_t align, int flags); |
| 160 | static void kmem_slab_free(void *ptr, vm_size_t bytes); |
| 161 | #if defined(INVARIANTS) |
| 162 | static void chunk_mark_allocated(SLZone *z, void *chunk); |
| 163 | static void chunk_mark_free(SLZone *z, void *chunk); |
| 164 | #endif |
| 165 | |
| 166 | /* |
| 167 | * Misc constants. Note that allocations that are exact multiples of |
| 168 | * PAGE_SIZE, or exceed the zone limit, fall through to the kmem module. |
| 169 | * IN_SAME_PAGE_MASK is used to sanity-check the per-page free lists. |
| 170 | */ |
| 171 | #define MIN_CHUNK_SIZE 8 /* in bytes */ |
| 172 | #define MIN_CHUNK_MASK (MIN_CHUNK_SIZE - 1) |
| 173 | #define ZONE_RELS_THRESH 2 /* threshold number of zones */ |
| 174 | #define IN_SAME_PAGE_MASK (~(intptr_t)PAGE_MASK | MIN_CHUNK_MASK) |
| 175 | |
| 176 | /* |
| 177 | * The WEIRD_ADDR is used as known text to copy into free objects to |
| 178 | * try to create deterministic failure cases if the data is accessed after |
| 179 | * free. |
| 180 | */ |
| 181 | #define WEIRD_ADDR 0xdeadc0de |
| 182 | #define MAX_COPY sizeof(weirdary) |
| 183 | #define ZERO_LENGTH_PTR ((void *)-8) |
| 184 | |
| 185 | /* |
| 186 | * Misc global malloc buckets |
| 187 | */ |
| 188 | |
| 189 | MALLOC_DEFINE(M_CACHE, "cache", "Various Dynamically allocated caches"); |
| 190 | MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory"); |
| 191 | MALLOC_DEFINE(M_TEMP, "temp", "misc temporary data buffers"); |
| 192 | |
| 193 | MALLOC_DEFINE(M_IP6OPT, "ip6opt", "IPv6 options"); |
| 194 | MALLOC_DEFINE(M_IP6NDP, "ip6ndp", "IPv6 Neighbor Discovery"); |
| 195 | |
| 196 | /* |
| 197 | * Initialize the slab memory allocator. We have to choose a zone size based |
| 198 | * on available physical memory. We choose a zone side which is approximately |
| 199 | * 1/1024th of our memory, so if we have 128MB of ram we have a zone size of |
| 200 | * 128K. The zone size is limited to the bounds set in slaballoc.h |
| 201 | * (typically 32K min, 128K max). |
| 202 | */ |
| 203 | static void kmeminit(void *dummy); |
| 204 | |
| 205 | SYSINIT(kmem, SI_SUB_KMEM, SI_ORDER_FIRST, kmeminit, NULL) |
| 206 | |
| 207 | #ifdef INVARIANTS |
| 208 | /* |
| 209 | * If enabled any memory allocated without M_ZERO is initialized to -1. |
| 210 | */ |
| 211 | static int use_malloc_pattern; |
| 212 | SYSCTL_INT(_debug, OID_AUTO, use_malloc_pattern, CTLFLAG_RW, |
| 213 | &use_malloc_pattern, 0, ""); |
| 214 | #endif |
| 215 | |
| 216 | static void |
| 217 | kmeminit(void *dummy) |
| 218 | { |
| 219 | vm_poff_t limsize; |
| 220 | int usesize; |
| 221 | int i; |
| 222 | vm_pindex_t npg; |
| 223 | |
| 224 | limsize = (vm_poff_t)vmstats.v_page_count * PAGE_SIZE; |
| 225 | if (limsize > KvaSize) |
| 226 | limsize = KvaSize; |
| 227 | |
| 228 | usesize = (int)(limsize / 1024); /* convert to KB */ |
| 229 | |
| 230 | ZoneSize = ZALLOC_MIN_ZONE_SIZE; |
| 231 | while (ZoneSize < ZALLOC_MAX_ZONE_SIZE && (ZoneSize << 1) < usesize) |
| 232 | ZoneSize <<= 1; |
| 233 | ZoneLimit = ZoneSize / 4; |
| 234 | if (ZoneLimit > ZALLOC_ZONE_LIMIT) |
| 235 | ZoneLimit = ZALLOC_ZONE_LIMIT; |
| 236 | ZoneMask = ZoneSize - 1; |
| 237 | ZonePageCount = ZoneSize / PAGE_SIZE; |
| 238 | |
| 239 | npg = KvaSize / PAGE_SIZE; |
| 240 | kmemusage = kmem_slab_alloc(npg * sizeof(struct kmemusage), |
| 241 | PAGE_SIZE, M_WAITOK|M_ZERO); |
| 242 | |
| 243 | for (i = 0; i < arysize(weirdary); ++i) |
| 244 | weirdary[i] = WEIRD_ADDR; |
| 245 | |
| 246 | if (bootverbose) |
| 247 | kprintf("Slab ZoneSize set to %dKB\n", ZoneSize / 1024); |
| 248 | } |
| 249 | |
| 250 | /* |
| 251 | * Initialize a malloc type tracking structure. |
| 252 | */ |
| 253 | void |
| 254 | malloc_init(void *data) |
| 255 | { |
| 256 | struct malloc_type *type = data; |
| 257 | vm_poff_t limsize; |
| 258 | |
| 259 | if (type->ks_magic != M_MAGIC) |
| 260 | panic("malloc type lacks magic"); |
| 261 | |
| 262 | if (type->ks_limit != 0) |
| 263 | return; |
| 264 | |
| 265 | if (vmstats.v_page_count == 0) |
| 266 | panic("malloc_init not allowed before vm init"); |
| 267 | |
| 268 | limsize = (vm_poff_t)vmstats.v_page_count * PAGE_SIZE; |
| 269 | if (limsize > KvaSize) |
| 270 | limsize = KvaSize; |
| 271 | type->ks_limit = limsize / 10; |
| 272 | |
| 273 | type->ks_next = kmemstatistics; |
| 274 | kmemstatistics = type; |
| 275 | } |
| 276 | |
| 277 | void |
| 278 | malloc_uninit(void *data) |
| 279 | { |
| 280 | struct malloc_type *type = data; |
| 281 | struct malloc_type *t; |
| 282 | #ifdef INVARIANTS |
| 283 | int i; |
| 284 | long ttl; |
| 285 | #endif |
| 286 | |
| 287 | if (type->ks_magic != M_MAGIC) |
| 288 | panic("malloc type lacks magic"); |
| 289 | |
| 290 | if (vmstats.v_page_count == 0) |
| 291 | panic("malloc_uninit not allowed before vm init"); |
| 292 | |
| 293 | if (type->ks_limit == 0) |
| 294 | panic("malloc_uninit on uninitialized type"); |
| 295 | |
| 296 | #ifdef INVARIANTS |
| 297 | /* |
| 298 | * memuse is only correct in aggregation. Due to memory being allocated |
| 299 | * on one cpu and freed on another individual array entries may be |
| 300 | * negative or positive (canceling each other out). |
| 301 | */ |
| 302 | for (i = ttl = 0; i < ncpus; ++i) |
| 303 | ttl += type->ks_memuse[i]; |
| 304 | if (ttl) { |
| 305 | kprintf("malloc_uninit: %ld bytes of '%s' still allocated on cpu %d\n", |
| 306 | ttl, type->ks_shortdesc, i); |
| 307 | } |
| 308 | #endif |
| 309 | if (type == kmemstatistics) { |
| 310 | kmemstatistics = type->ks_next; |
| 311 | } else { |
| 312 | for (t = kmemstatistics; t->ks_next != NULL; t = t->ks_next) { |
| 313 | if (t->ks_next == type) { |
| 314 | t->ks_next = type->ks_next; |
| 315 | break; |
| 316 | } |
| 317 | } |
| 318 | } |
| 319 | type->ks_next = NULL; |
| 320 | type->ks_limit = 0; |
| 321 | } |
| 322 | |
| 323 | /* |
| 324 | * Calculate the zone index for the allocation request size and set the |
| 325 | * allocation request size to that particular zone's chunk size. |
| 326 | */ |
| 327 | static __inline int |
| 328 | zoneindex(unsigned long *bytes) |
| 329 | { |
| 330 | unsigned int n = (unsigned int)*bytes; /* unsigned for shift opt */ |
| 331 | if (n < 128) { |
| 332 | *bytes = n = (n + 7) & ~7; |
| 333 | return(n / 8 - 1); /* 8 byte chunks, 16 zones */ |
| 334 | } |
| 335 | if (n < 256) { |
| 336 | *bytes = n = (n + 15) & ~15; |
| 337 | return(n / 16 + 7); |
| 338 | } |
| 339 | if (n < 8192) { |
| 340 | if (n < 512) { |
| 341 | *bytes = n = (n + 31) & ~31; |
| 342 | return(n / 32 + 15); |
| 343 | } |
| 344 | if (n < 1024) { |
| 345 | *bytes = n = (n + 63) & ~63; |
| 346 | return(n / 64 + 23); |
| 347 | } |
| 348 | if (n < 2048) { |
| 349 | *bytes = n = (n + 127) & ~127; |
| 350 | return(n / 128 + 31); |
| 351 | } |
| 352 | if (n < 4096) { |
| 353 | *bytes = n = (n + 255) & ~255; |
| 354 | return(n / 256 + 39); |
| 355 | } |
| 356 | *bytes = n = (n + 511) & ~511; |
| 357 | return(n / 512 + 47); |
| 358 | } |
| 359 | #if ZALLOC_ZONE_LIMIT > 8192 |
| 360 | if (n < 16384) { |
| 361 | *bytes = n = (n + 1023) & ~1023; |
| 362 | return(n / 1024 + 55); |
| 363 | } |
| 364 | #endif |
| 365 | #if ZALLOC_ZONE_LIMIT > 16384 |
| 366 | if (n < 32768) { |
| 367 | *bytes = n = (n + 2047) & ~2047; |
| 368 | return(n / 2048 + 63); |
| 369 | } |
| 370 | #endif |
| 371 | panic("Unexpected byte count %d", n); |
| 372 | return(0); |
| 373 | } |
| 374 | |
| 375 | /* |
| 376 | * malloc() (SLAB ALLOCATOR) |
| 377 | * |
| 378 | * Allocate memory via the slab allocator. If the request is too large, |
| 379 | * or if it page-aligned beyond a certain size, we fall back to the |
| 380 | * KMEM subsystem. A SLAB tracking descriptor must be specified, use |
| 381 | * &SlabMisc if you don't care. |
| 382 | * |
| 383 | * M_RNOWAIT - don't block. |
| 384 | * M_NULLOK - return NULL instead of blocking. |
| 385 | * M_ZERO - zero the returned memory. |
| 386 | * M_USE_RESERVE - allow greater drawdown of the free list |
| 387 | * M_USE_INTERRUPT_RESERVE - allow the freelist to be exhausted |
| 388 | * |
| 389 | * MPSAFE |
| 390 | */ |
| 391 | |
| 392 | void * |
| 393 | kmalloc(unsigned long size, struct malloc_type *type, int flags) |
| 394 | { |
| 395 | SLZone *z; |
| 396 | SLChunk *chunk; |
| 397 | SLGlobalData *slgd; |
| 398 | struct globaldata *gd; |
| 399 | int zi; |
| 400 | #ifdef INVARIANTS |
| 401 | int i; |
| 402 | #endif |
| 403 | |
| 404 | logmemory_quick(malloc_beg); |
| 405 | gd = mycpu; |
| 406 | slgd = &gd->gd_slab; |
| 407 | |
| 408 | /* |
| 409 | * XXX silly to have this in the critical path. |
| 410 | */ |
| 411 | if (type->ks_limit == 0) { |
| 412 | crit_enter(); |
| 413 | if (type->ks_limit == 0) |
| 414 | malloc_init(type); |
| 415 | crit_exit(); |
| 416 | } |
| 417 | ++type->ks_calls; |
| 418 | |
| 419 | /* |
| 420 | * Handle the case where the limit is reached. Panic if we can't return |
| 421 | * NULL. The original malloc code looped, but this tended to |
| 422 | * simply deadlock the computer. |
| 423 | * |
| 424 | * ks_loosememuse is an up-only limit that is NOT MP-synchronized, used |
| 425 | * to determine if a more complete limit check should be done. The |
| 426 | * actual memory use is tracked via ks_memuse[cpu]. |
| 427 | */ |
| 428 | while (type->ks_loosememuse >= type->ks_limit) { |
| 429 | int i; |
| 430 | long ttl; |
| 431 | |
| 432 | for (i = ttl = 0; i < ncpus; ++i) |
| 433 | ttl += type->ks_memuse[i]; |
| 434 | type->ks_loosememuse = ttl; /* not MP synchronized */ |
| 435 | if (ttl >= type->ks_limit) { |
| 436 | if (flags & M_NULLOK) { |
| 437 | logmemory(malloc, NULL, type, size, flags); |
| 438 | return(NULL); |
| 439 | } |
| 440 | panic("%s: malloc limit exceeded", type->ks_shortdesc); |
| 441 | } |
| 442 | } |
| 443 | |
| 444 | /* |
| 445 | * Handle the degenerate size == 0 case. Yes, this does happen. |
| 446 | * Return a special pointer. This is to maintain compatibility with |
| 447 | * the original malloc implementation. Certain devices, such as the |
| 448 | * adaptec driver, not only allocate 0 bytes, they check for NULL and |
| 449 | * also realloc() later on. Joy. |
| 450 | */ |
| 451 | if (size == 0) { |
| 452 | logmemory(malloc, ZERO_LENGTH_PTR, type, size, flags); |
| 453 | return(ZERO_LENGTH_PTR); |
| 454 | } |
| 455 | |
| 456 | /* |
| 457 | * Handle hysteresis from prior frees here in malloc(). We cannot |
| 458 | * safely manipulate the kernel_map in free() due to free() possibly |
| 459 | * being called via an IPI message or from sensitive interrupt code. |
| 460 | */ |
| 461 | while (slgd->NFreeZones > ZONE_RELS_THRESH && (flags & M_RNOWAIT) == 0) { |
| 462 | crit_enter(); |
| 463 | if (slgd->NFreeZones > ZONE_RELS_THRESH) { /* crit sect race */ |
| 464 | z = slgd->FreeZones; |
| 465 | slgd->FreeZones = z->z_Next; |
| 466 | --slgd->NFreeZones; |
| 467 | kmem_slab_free(z, ZoneSize); /* may block */ |
| 468 | } |
| 469 | crit_exit(); |
| 470 | } |
| 471 | /* |
| 472 | * XXX handle oversized frees that were queued from free(). |
| 473 | */ |
| 474 | while (slgd->FreeOvZones && (flags & M_RNOWAIT) == 0) { |
| 475 | crit_enter(); |
| 476 | if ((z = slgd->FreeOvZones) != NULL) { |
| 477 | KKASSERT(z->z_Magic == ZALLOC_OVSZ_MAGIC); |
| 478 | slgd->FreeOvZones = z->z_Next; |
| 479 | kmem_slab_free(z, z->z_ChunkSize); /* may block */ |
| 480 | } |
| 481 | crit_exit(); |
| 482 | } |
| 483 | |
| 484 | /* |
| 485 | * Handle large allocations directly. There should not be very many of |
| 486 | * these so performance is not a big issue. |
| 487 | * |
| 488 | * Guarentee page alignment for allocations in multiples of PAGE_SIZE |
| 489 | */ |
| 490 | if (size >= ZoneLimit || (size & PAGE_MASK) == 0) { |
| 491 | struct kmemusage *kup; |
| 492 | |
| 493 | size = round_page(size); |
| 494 | chunk = kmem_slab_alloc(size, PAGE_SIZE, flags); |
| 495 | if (chunk == NULL) { |
| 496 | logmemory(malloc, NULL, type, size, flags); |
| 497 | return(NULL); |
| 498 | } |
| 499 | flags &= ~M_ZERO; /* result already zero'd if M_ZERO was set */ |
| 500 | flags |= M_PASSIVE_ZERO; |
| 501 | kup = btokup(chunk); |
| 502 | kup->ku_pagecnt = size / PAGE_SIZE; |
| 503 | kup->ku_cpu = gd->gd_cpuid; |
| 504 | crit_enter(); |
| 505 | goto done; |
| 506 | } |
| 507 | |
| 508 | /* |
| 509 | * Attempt to allocate out of an existing zone. First try the free list, |
| 510 | * then allocate out of unallocated space. If we find a good zone move |
| 511 | * it to the head of the list so later allocations find it quickly |
| 512 | * (we might have thousands of zones in the list). |
| 513 | * |
| 514 | * Note: zoneindex() will panic of size is too large. |
| 515 | */ |
| 516 | zi = zoneindex(&size); |
| 517 | KKASSERT(zi < NZONES); |
| 518 | crit_enter(); |
| 519 | if ((z = slgd->ZoneAry[zi]) != NULL) { |
| 520 | KKASSERT(z->z_NFree > 0); |
| 521 | |
| 522 | /* |
| 523 | * Remove us from the ZoneAry[] when we become empty |
| 524 | */ |
| 525 | if (--z->z_NFree == 0) { |
| 526 | slgd->ZoneAry[zi] = z->z_Next; |
| 527 | z->z_Next = NULL; |
| 528 | } |
| 529 | |
| 530 | /* |
| 531 | * Locate a chunk in a free page. This attempts to localize |
| 532 | * reallocations into earlier pages without us having to sort |
| 533 | * the chunk list. A chunk may still overlap a page boundary. |
| 534 | */ |
| 535 | while (z->z_FirstFreePg < ZonePageCount) { |
| 536 | if ((chunk = z->z_PageAry[z->z_FirstFreePg]) != NULL) { |
| 537 | #ifdef DIAGNOSTIC |
| 538 | /* |
| 539 | * Diagnostic: c_Next is not total garbage. |
| 540 | */ |
| 541 | KKASSERT(chunk->c_Next == NULL || |
| 542 | ((intptr_t)chunk->c_Next & IN_SAME_PAGE_MASK) == |
| 543 | ((intptr_t)chunk & IN_SAME_PAGE_MASK)); |
| 544 | #endif |
| 545 | #ifdef INVARIANTS |
| 546 | if ((vm_offset_t)chunk < KvaStart || (vm_offset_t)chunk >= KvaEnd) |
| 547 | panic("chunk %p FFPG %d/%d", chunk, z->z_FirstFreePg, ZonePageCount); |
| 548 | if (chunk->c_Next && (vm_offset_t)chunk->c_Next < KvaStart) |
| 549 | panic("chunkNEXT %p %p FFPG %d/%d", chunk, chunk->c_Next, z->z_FirstFreePg, ZonePageCount); |
| 550 | chunk_mark_allocated(z, chunk); |
| 551 | #endif |
| 552 | z->z_PageAry[z->z_FirstFreePg] = chunk->c_Next; |
| 553 | goto done; |
| 554 | } |
| 555 | ++z->z_FirstFreePg; |
| 556 | } |
| 557 | |
| 558 | /* |
| 559 | * No chunks are available but NFree said we had some memory, so |
| 560 | * it must be available in the never-before-used-memory area |
| 561 | * governed by UIndex. The consequences are very serious if our zone |
| 562 | * got corrupted so we use an explicit panic rather then a KASSERT. |
| 563 | */ |
| 564 | if (z->z_UIndex + 1 != z->z_NMax) |
| 565 | z->z_UIndex = z->z_UIndex + 1; |
| 566 | else |
| 567 | z->z_UIndex = 0; |
| 568 | if (z->z_UIndex == z->z_UEndIndex) |
| 569 | panic("slaballoc: corrupted zone"); |
| 570 | chunk = (SLChunk *)(z->z_BasePtr + z->z_UIndex * size); |
| 571 | if ((z->z_Flags & SLZF_UNOTZEROD) == 0) { |
| 572 | flags &= ~M_ZERO; |
| 573 | flags |= M_PASSIVE_ZERO; |
| 574 | } |
| 575 | #if defined(INVARIANTS) |
| 576 | chunk_mark_allocated(z, chunk); |
| 577 | #endif |
| 578 | goto done; |
| 579 | } |
| 580 | |
| 581 | /* |
| 582 | * If all zones are exhausted we need to allocate a new zone for this |
| 583 | * index. Use M_ZERO to take advantage of pre-zerod pages. Also see |
| 584 | * UAlloc use above in regards to M_ZERO. Note that when we are reusing |
| 585 | * a zone from the FreeZones list UAlloc'd data will not be zero'd, and |
| 586 | * we do not pre-zero it because we do not want to mess up the L1 cache. |
| 587 | * |
| 588 | * At least one subsystem, the tty code (see CROUND) expects power-of-2 |
| 589 | * allocations to be power-of-2 aligned. We maintain compatibility by |
| 590 | * adjusting the base offset below. |
| 591 | */ |
| 592 | { |
| 593 | int off; |
| 594 | |
| 595 | if ((z = slgd->FreeZones) != NULL) { |
| 596 | slgd->FreeZones = z->z_Next; |
| 597 | --slgd->NFreeZones; |
| 598 | bzero(z, sizeof(SLZone)); |
| 599 | z->z_Flags |= SLZF_UNOTZEROD; |
| 600 | } else { |
| 601 | z = kmem_slab_alloc(ZoneSize, ZoneSize, flags|M_ZERO); |
| 602 | if (z == NULL) |
| 603 | goto fail; |
| 604 | } |
| 605 | |
| 606 | /* |
| 607 | * How big is the base structure? |
| 608 | */ |
| 609 | #if defined(INVARIANTS) |
| 610 | /* |
| 611 | * Make room for z_Bitmap. An exact calculation is somewhat more |
| 612 | * complicated so don't make an exact calculation. |
| 613 | */ |
| 614 | off = offsetof(SLZone, z_Bitmap[(ZoneSize / size + 31) / 32]); |
| 615 | bzero(z->z_Bitmap, (ZoneSize / size + 31) / 8); |
| 616 | #else |
| 617 | off = sizeof(SLZone); |
| 618 | #endif |
| 619 | |
| 620 | /* |
| 621 | * Guarentee power-of-2 alignment for power-of-2-sized chunks. |
| 622 | * Otherwise just 8-byte align the data. |
| 623 | */ |
| 624 | if ((size | (size - 1)) + 1 == (size << 1)) |
| 625 | off = (off + size - 1) & ~(size - 1); |
| 626 | else |
| 627 | off = (off + MIN_CHUNK_MASK) & ~MIN_CHUNK_MASK; |
| 628 | z->z_Magic = ZALLOC_SLAB_MAGIC; |
| 629 | z->z_ZoneIndex = zi; |
| 630 | z->z_NMax = (ZoneSize - off) / size; |
| 631 | z->z_NFree = z->z_NMax - 1; |
| 632 | z->z_BasePtr = (char *)z + off; |
| 633 | z->z_UIndex = z->z_UEndIndex = slgd->JunkIndex % z->z_NMax; |
| 634 | z->z_ChunkSize = size; |
| 635 | z->z_FirstFreePg = ZonePageCount; |
| 636 | z->z_CpuGd = gd; |
| 637 | z->z_Cpu = gd->gd_cpuid; |
| 638 | chunk = (SLChunk *)(z->z_BasePtr + z->z_UIndex * size); |
| 639 | z->z_Next = slgd->ZoneAry[zi]; |
| 640 | slgd->ZoneAry[zi] = z; |
| 641 | if ((z->z_Flags & SLZF_UNOTZEROD) == 0) { |
| 642 | flags &= ~M_ZERO; /* already zero'd */ |
| 643 | flags |= M_PASSIVE_ZERO; |
| 644 | } |
| 645 | #if defined(INVARIANTS) |
| 646 | chunk_mark_allocated(z, chunk); |
| 647 | #endif |
| 648 | |
| 649 | /* |
| 650 | * Slide the base index for initial allocations out of the next |
| 651 | * zone we create so we do not over-weight the lower part of the |
| 652 | * cpu memory caches. |
| 653 | */ |
| 654 | slgd->JunkIndex = (slgd->JunkIndex + ZALLOC_SLAB_SLIDE) |
| 655 | & (ZALLOC_MAX_ZONE_SIZE - 1); |
| 656 | } |
| 657 | done: |
| 658 | ++type->ks_inuse[gd->gd_cpuid]; |
| 659 | type->ks_memuse[gd->gd_cpuid] += size; |
| 660 | type->ks_loosememuse += size; /* not MP synchronized */ |
| 661 | crit_exit(); |
| 662 | if (flags & M_ZERO) |
| 663 | bzero(chunk, size); |
| 664 | #ifdef INVARIANTS |
| 665 | else if ((flags & (M_ZERO|M_PASSIVE_ZERO)) == 0) { |
| 666 | if (use_malloc_pattern) { |
| 667 | for (i = 0; i < size; i += sizeof(int)) { |
| 668 | *(int *)((char *)chunk + i) = -1; |
| 669 | } |
| 670 | } |
| 671 | chunk->c_Next = (void *)-1; /* avoid accidental double-free check */ |
| 672 | } |
| 673 | #endif |
| 674 | logmemory(malloc, chunk, type, size, flags); |
| 675 | return(chunk); |
| 676 | fail: |
| 677 | crit_exit(); |
| 678 | logmemory(malloc, NULL, type, size, flags); |
| 679 | return(NULL); |
| 680 | } |
| 681 | |
| 682 | /* |
| 683 | * kernel realloc. (SLAB ALLOCATOR) (MP SAFE) |
| 684 | * |
| 685 | * Generally speaking this routine is not called very often and we do |
| 686 | * not attempt to optimize it beyond reusing the same pointer if the |
| 687 | * new size fits within the chunking of the old pointer's zone. |
| 688 | */ |
| 689 | void * |
| 690 | krealloc(void *ptr, unsigned long size, struct malloc_type *type, int flags) |
| 691 | { |
| 692 | SLZone *z; |
| 693 | void *nptr; |
| 694 | unsigned long osize; |
| 695 | |
| 696 | KKASSERT((flags & M_ZERO) == 0); /* not supported */ |
| 697 | |
| 698 | if (ptr == NULL || ptr == ZERO_LENGTH_PTR) |
| 699 | return(kmalloc(size, type, flags)); |
| 700 | if (size == 0) { |
| 701 | kfree(ptr, type); |
| 702 | return(NULL); |
| 703 | } |
| 704 | |
| 705 | /* |
| 706 | * Handle oversized allocations. XXX we really should require that a |
| 707 | * size be passed to free() instead of this nonsense. |
| 708 | */ |
| 709 | { |
| 710 | struct kmemusage *kup; |
| 711 | |
| 712 | kup = btokup(ptr); |
| 713 | if (kup->ku_pagecnt) { |
| 714 | osize = kup->ku_pagecnt << PAGE_SHIFT; |
| 715 | if (osize == round_page(size)) |
| 716 | return(ptr); |
| 717 | if ((nptr = kmalloc(size, type, flags)) == NULL) |
| 718 | return(NULL); |
| 719 | bcopy(ptr, nptr, min(size, osize)); |
| 720 | kfree(ptr, type); |
| 721 | return(nptr); |
| 722 | } |
| 723 | } |
| 724 | |
| 725 | /* |
| 726 | * Get the original allocation's zone. If the new request winds up |
| 727 | * using the same chunk size we do not have to do anything. |
| 728 | */ |
| 729 | z = (SLZone *)((uintptr_t)ptr & ~(uintptr_t)ZoneMask); |
| 730 | KKASSERT(z->z_Magic == ZALLOC_SLAB_MAGIC); |
| 731 | |
| 732 | zoneindex(&size); |
| 733 | if (z->z_ChunkSize == size) |
| 734 | return(ptr); |
| 735 | |
| 736 | /* |
| 737 | * Allocate memory for the new request size. Note that zoneindex has |
| 738 | * already adjusted the request size to the appropriate chunk size, which |
| 739 | * should optimize our bcopy(). Then copy and return the new pointer. |
| 740 | */ |
| 741 | if ((nptr = kmalloc(size, type, flags)) == NULL) |
| 742 | return(NULL); |
| 743 | bcopy(ptr, nptr, min(size, z->z_ChunkSize)); |
| 744 | kfree(ptr, type); |
| 745 | return(nptr); |
| 746 | } |
| 747 | |
| 748 | /* |
| 749 | * Allocate a copy of the specified string. |
| 750 | * |
| 751 | * (MP SAFE) (MAY BLOCK) |
| 752 | */ |
| 753 | char * |
| 754 | kstrdup(const char *str, struct malloc_type *type) |
| 755 | { |
| 756 | int zlen; /* length inclusive of terminating NUL */ |
| 757 | char *nstr; |
| 758 | |
| 759 | if (str == NULL) |
| 760 | return(NULL); |
| 761 | zlen = strlen(str) + 1; |
| 762 | nstr = kmalloc(zlen, type, M_WAITOK); |
| 763 | bcopy(str, nstr, zlen); |
| 764 | return(nstr); |
| 765 | } |
| 766 | |
| 767 | #ifdef SMP |
| 768 | /* |
| 769 | * free() (SLAB ALLOCATOR) |
| 770 | * |
| 771 | * Free the specified chunk of memory. |
| 772 | */ |
| 773 | static |
| 774 | void |
| 775 | free_remote(void *ptr) |
| 776 | { |
| 777 | logmemory(free_remote, ptr, *(struct malloc_type **)ptr, -1, 0); |
| 778 | kfree(ptr, *(struct malloc_type **)ptr); |
| 779 | } |
| 780 | |
| 781 | #endif |
| 782 | |
| 783 | /* |
| 784 | * free (SLAB ALLOCATOR) |
| 785 | * |
| 786 | * Free a memory block previously allocated by malloc. Note that we do not |
| 787 | * attempt to uplodate ks_loosememuse as MP races could prevent us from |
| 788 | * checking memory limits in malloc. |
| 789 | * |
| 790 | * MPSAFE |
| 791 | */ |
| 792 | void |
| 793 | kfree(void *ptr, struct malloc_type *type) |
| 794 | { |
| 795 | SLZone *z; |
| 796 | SLChunk *chunk; |
| 797 | SLGlobalData *slgd; |
| 798 | struct globaldata *gd; |
| 799 | int pgno; |
| 800 | |
| 801 | logmemory_quick(free_beg); |
| 802 | gd = mycpu; |
| 803 | slgd = &gd->gd_slab; |
| 804 | |
| 805 | if (ptr == NULL) |
| 806 | panic("trying to free NULL pointer"); |
| 807 | |
| 808 | /* |
| 809 | * Handle special 0-byte allocations |
| 810 | */ |
| 811 | if (ptr == ZERO_LENGTH_PTR) { |
| 812 | logmemory(free_zero, ptr, type, -1, 0); |
| 813 | logmemory_quick(free_end); |
| 814 | return; |
| 815 | } |
| 816 | |
| 817 | /* |
| 818 | * Handle oversized allocations. XXX we really should require that a |
| 819 | * size be passed to free() instead of this nonsense. |
| 820 | * |
| 821 | * This code is never called via an ipi. |
| 822 | */ |
| 823 | { |
| 824 | struct kmemusage *kup; |
| 825 | unsigned long size; |
| 826 | |
| 827 | kup = btokup(ptr); |
| 828 | if (kup->ku_pagecnt) { |
| 829 | size = kup->ku_pagecnt << PAGE_SHIFT; |
| 830 | kup->ku_pagecnt = 0; |
| 831 | #ifdef INVARIANTS |
| 832 | KKASSERT(sizeof(weirdary) <= size); |
| 833 | bcopy(weirdary, ptr, sizeof(weirdary)); |
| 834 | #endif |
| 835 | /* |
| 836 | * note: we always adjust our cpu's slot, not the originating |
| 837 | * cpu (kup->ku_cpuid). The statistics are in aggregate. |
| 838 | * |
| 839 | * note: XXX we have still inherited the interrupts-can't-block |
| 840 | * assumption. An interrupt thread does not bump |
| 841 | * gd_intr_nesting_level so check TDF_INTTHREAD. This is |
| 842 | * primarily until we can fix softupdate's assumptions about free(). |
| 843 | */ |
| 844 | crit_enter(); |
| 845 | --type->ks_inuse[gd->gd_cpuid]; |
| 846 | type->ks_memuse[gd->gd_cpuid] -= size; |
| 847 | if (mycpu->gd_intr_nesting_level || (gd->gd_curthread->td_flags & TDF_INTTHREAD)) { |
| 848 | logmemory(free_ovsz_delayed, ptr, type, size, 0); |
| 849 | z = (SLZone *)ptr; |
| 850 | z->z_Magic = ZALLOC_OVSZ_MAGIC; |
| 851 | z->z_Next = slgd->FreeOvZones; |
| 852 | z->z_ChunkSize = size; |
| 853 | slgd->FreeOvZones = z; |
| 854 | crit_exit(); |
| 855 | } else { |
| 856 | crit_exit(); |
| 857 | logmemory(free_ovsz, ptr, type, size, 0); |
| 858 | kmem_slab_free(ptr, size); /* may block */ |
| 859 | } |
| 860 | logmemory_quick(free_end); |
| 861 | return; |
| 862 | } |
| 863 | } |
| 864 | |
| 865 | /* |
| 866 | * Zone case. Figure out the zone based on the fact that it is |
| 867 | * ZoneSize aligned. |
| 868 | */ |
| 869 | z = (SLZone *)((uintptr_t)ptr & ~(uintptr_t)ZoneMask); |
| 870 | KKASSERT(z->z_Magic == ZALLOC_SLAB_MAGIC); |
| 871 | |
| 872 | /* |
| 873 | * If we do not own the zone then forward the request to the |
| 874 | * cpu that does. Since the timing is non-critical, a passive |
| 875 | * message is sent. |
| 876 | */ |
| 877 | if (z->z_CpuGd != gd) { |
| 878 | *(struct malloc_type **)ptr = type; |
| 879 | #ifdef SMP |
| 880 | logmemory(free_request, ptr, type, z->z_ChunkSize, 0); |
| 881 | lwkt_send_ipiq_passive(z->z_CpuGd, free_remote, ptr); |
| 882 | #else |
| 883 | panic("Corrupt SLZone"); |
| 884 | #endif |
| 885 | logmemory_quick(free_end); |
| 886 | return; |
| 887 | } |
| 888 | |
| 889 | logmemory(free_chunk, ptr, type, z->z_ChunkSize, 0); |
| 890 | |
| 891 | if (type->ks_magic != M_MAGIC) |
| 892 | panic("free: malloc type lacks magic"); |
| 893 | |
| 894 | crit_enter(); |
| 895 | pgno = ((char *)ptr - (char *)z) >> PAGE_SHIFT; |
| 896 | chunk = ptr; |
| 897 | |
| 898 | #ifdef INVARIANTS |
| 899 | /* |
| 900 | * Attempt to detect a double-free. To reduce overhead we only check |
| 901 | * if there appears to be link pointer at the base of the data. |
| 902 | */ |
| 903 | if (((intptr_t)chunk->c_Next - (intptr_t)z) >> PAGE_SHIFT == pgno) { |
| 904 | SLChunk *scan; |
| 905 | for (scan = z->z_PageAry[pgno]; scan; scan = scan->c_Next) { |
| 906 | if (scan == chunk) |
| 907 | panic("Double free at %p", chunk); |
| 908 | } |
| 909 | } |
| 910 | chunk_mark_free(z, chunk); |
| 911 | #endif |
| 912 | |
| 913 | /* |
| 914 | * Put weird data into the memory to detect modifications after freeing, |
| 915 | * illegal pointer use after freeing (we should fault on the odd address), |
| 916 | * and so forth. XXX needs more work, see the old malloc code. |
| 917 | */ |
| 918 | #ifdef INVARIANTS |
| 919 | if (z->z_ChunkSize < sizeof(weirdary)) |
| 920 | bcopy(weirdary, chunk, z->z_ChunkSize); |
| 921 | else |
| 922 | bcopy(weirdary, chunk, sizeof(weirdary)); |
| 923 | #endif |
| 924 | |
| 925 | /* |
| 926 | * Add this free non-zero'd chunk to a linked list for reuse, adjust |
| 927 | * z_FirstFreePg. |
| 928 | */ |
| 929 | #ifdef INVARIANTS |
| 930 | if ((vm_offset_t)chunk < KvaStart || (vm_offset_t)chunk >= KvaEnd) |
| 931 | panic("BADFREE %p", chunk); |
| 932 | #endif |
| 933 | chunk->c_Next = z->z_PageAry[pgno]; |
| 934 | z->z_PageAry[pgno] = chunk; |
| 935 | #ifdef INVARIANTS |
| 936 | if (chunk->c_Next && (vm_offset_t)chunk->c_Next < KvaStart) |
| 937 | panic("BADFREE2"); |
| 938 | #endif |
| 939 | if (z->z_FirstFreePg > pgno) |
| 940 | z->z_FirstFreePg = pgno; |
| 941 | |
| 942 | /* |
| 943 | * Bump the number of free chunks. If it becomes non-zero the zone |
| 944 | * must be added back onto the appropriate list. |
| 945 | */ |
| 946 | if (z->z_NFree++ == 0) { |
| 947 | z->z_Next = slgd->ZoneAry[z->z_ZoneIndex]; |
| 948 | slgd->ZoneAry[z->z_ZoneIndex] = z; |
| 949 | } |
| 950 | |
| 951 | --type->ks_inuse[z->z_Cpu]; |
| 952 | type->ks_memuse[z->z_Cpu] -= z->z_ChunkSize; |
| 953 | |
| 954 | /* |
| 955 | * If the zone becomes totally free, and there are other zones we |
| 956 | * can allocate from, move this zone to the FreeZones list. Since |
| 957 | * this code can be called from an IPI callback, do *NOT* try to mess |
| 958 | * with kernel_map here. Hysteresis will be performed at malloc() time. |
| 959 | */ |
| 960 | if (z->z_NFree == z->z_NMax && |
| 961 | (z->z_Next || slgd->ZoneAry[z->z_ZoneIndex] != z) |
| 962 | ) { |
| 963 | SLZone **pz; |
| 964 | |
| 965 | for (pz = &slgd->ZoneAry[z->z_ZoneIndex]; z != *pz; pz = &(*pz)->z_Next) |
| 966 | ; |
| 967 | *pz = z->z_Next; |
| 968 | z->z_Magic = -1; |
| 969 | z->z_Next = slgd->FreeZones; |
| 970 | slgd->FreeZones = z; |
| 971 | ++slgd->NFreeZones; |
| 972 | } |
| 973 | logmemory_quick(free_end); |
| 974 | crit_exit(); |
| 975 | } |
| 976 | |
| 977 | #if defined(INVARIANTS) |
| 978 | /* |
| 979 | * Helper routines for sanity checks |
| 980 | */ |
| 981 | static |
| 982 | void |
| 983 | chunk_mark_allocated(SLZone *z, void *chunk) |
| 984 | { |
| 985 | int bitdex = ((char *)chunk - (char *)z->z_BasePtr) / z->z_ChunkSize; |
| 986 | __uint32_t *bitptr; |
| 987 | |
| 988 | KASSERT(bitdex >= 0 && bitdex < z->z_NMax, ("memory chunk %p bit index %d is illegal", chunk, bitdex)); |
| 989 | bitptr = &z->z_Bitmap[bitdex >> 5]; |
| 990 | bitdex &= 31; |
| 991 | KASSERT((*bitptr & (1 << bitdex)) == 0, ("memory chunk %p is already allocated!", chunk)); |
| 992 | *bitptr |= 1 << bitdex; |
| 993 | } |
| 994 | |
| 995 | static |
| 996 | void |
| 997 | chunk_mark_free(SLZone *z, void *chunk) |
| 998 | { |
| 999 | int bitdex = ((char *)chunk - (char *)z->z_BasePtr) / z->z_ChunkSize; |
| 1000 | __uint32_t *bitptr; |
| 1001 | |
| 1002 | KASSERT(bitdex >= 0 && bitdex < z->z_NMax, ("memory chunk %p bit index %d is illegal!", chunk, bitdex)); |
| 1003 | bitptr = &z->z_Bitmap[bitdex >> 5]; |
| 1004 | bitdex &= 31; |
| 1005 | KASSERT((*bitptr & (1 << bitdex)) != 0, ("memory chunk %p is already free!", chunk)); |
| 1006 | *bitptr &= ~(1 << bitdex); |
| 1007 | } |
| 1008 | |
| 1009 | #endif |
| 1010 | |
| 1011 | /* |
| 1012 | * kmem_slab_alloc() |
| 1013 | * |
| 1014 | * Directly allocate and wire kernel memory in PAGE_SIZE chunks with the |
| 1015 | * specified alignment. M_* flags are expected in the flags field. |
| 1016 | * |
| 1017 | * Alignment must be a multiple of PAGE_SIZE. |
| 1018 | * |
| 1019 | * NOTE! XXX For the moment we use vm_map_entry_reserve/release(), |
| 1020 | * but when we move zalloc() over to use this function as its backend |
| 1021 | * we will have to switch to kreserve/krelease and call reserve(0) |
| 1022 | * after the new space is made available. |
| 1023 | * |
| 1024 | * Interrupt code which has preempted other code is not allowed to |
| 1025 | * use PQ_CACHE pages. However, if an interrupt thread is run |
| 1026 | * non-preemptively or blocks and then runs non-preemptively, then |
| 1027 | * it is free to use PQ_CACHE pages. |
| 1028 | * |
| 1029 | * This routine will currently obtain the BGL. |
| 1030 | * |
| 1031 | * MPALMOSTSAFE - acquires mplock |
| 1032 | */ |
| 1033 | static void * |
| 1034 | kmem_slab_alloc(vm_size_t size, vm_offset_t align, int flags) |
| 1035 | { |
| 1036 | vm_size_t i; |
| 1037 | vm_offset_t addr; |
| 1038 | int count, vmflags, base_vmflags; |
| 1039 | thread_t td; |
| 1040 | |
| 1041 | size = round_page(size); |
| 1042 | addr = vm_map_min(&kernel_map); |
| 1043 | |
| 1044 | /* |
| 1045 | * Reserve properly aligned space from kernel_map. RNOWAIT allocations |
| 1046 | * cannot block. |
| 1047 | */ |
| 1048 | if (flags & M_RNOWAIT) { |
| 1049 | if (try_mplock() == 0) |
| 1050 | return(NULL); |
| 1051 | } else { |
| 1052 | get_mplock(); |
| 1053 | } |
| 1054 | count = vm_map_entry_reserve(MAP_RESERVE_COUNT); |
| 1055 | crit_enter(); |
| 1056 | vm_map_lock(&kernel_map); |
| 1057 | if (vm_map_findspace(&kernel_map, addr, size, align, &addr)) { |
| 1058 | vm_map_unlock(&kernel_map); |
| 1059 | if ((flags & M_NULLOK) == 0) |
| 1060 | panic("kmem_slab_alloc(): kernel_map ran out of space!"); |
| 1061 | crit_exit(); |
| 1062 | vm_map_entry_release(count); |
| 1063 | rel_mplock(); |
| 1064 | return(NULL); |
| 1065 | } |
| 1066 | |
| 1067 | /* |
| 1068 | * kernel_object maps 1:1 to kernel_map. |
| 1069 | */ |
| 1070 | vm_object_reference(&kernel_object); |
| 1071 | vm_map_insert(&kernel_map, &count, |
| 1072 | &kernel_object, addr, addr, addr + size, |
| 1073 | VM_MAPTYPE_NORMAL, |
| 1074 | VM_PROT_ALL, VM_PROT_ALL, |
| 1075 | 0); |
| 1076 | |
| 1077 | td = curthread; |
| 1078 | |
| 1079 | base_vmflags = 0; |
| 1080 | if (flags & M_ZERO) |
| 1081 | base_vmflags |= VM_ALLOC_ZERO; |
| 1082 | if (flags & M_USE_RESERVE) |
| 1083 | base_vmflags |= VM_ALLOC_SYSTEM; |
| 1084 | if (flags & M_USE_INTERRUPT_RESERVE) |
| 1085 | base_vmflags |= VM_ALLOC_INTERRUPT; |
| 1086 | if ((flags & (M_RNOWAIT|M_WAITOK)) == 0) |
| 1087 | panic("kmem_slab_alloc: bad flags %08x (%p)", flags, ((int **)&size)[-1]); |
| 1088 | |
| 1089 | |
| 1090 | /* |
| 1091 | * Allocate the pages. Do not mess with the PG_ZERO flag yet. |
| 1092 | */ |
| 1093 | for (i = 0; i < size; i += PAGE_SIZE) { |
| 1094 | vm_page_t m; |
| 1095 | |
| 1096 | /* |
| 1097 | * VM_ALLOC_NORMAL can only be set if we are not preempting. |
| 1098 | * |
| 1099 | * VM_ALLOC_SYSTEM is automatically set if we are preempting and |
| 1100 | * M_WAITOK was specified as an alternative (i.e. M_USE_RESERVE is |
| 1101 | * implied in this case), though I'm sure if we really need to do |
| 1102 | * that. |
| 1103 | */ |
| 1104 | vmflags = base_vmflags; |
| 1105 | if (flags & M_WAITOK) { |
| 1106 | if (td->td_preempted) |
| 1107 | vmflags |= VM_ALLOC_SYSTEM; |
| 1108 | else |
| 1109 | vmflags |= VM_ALLOC_NORMAL; |
| 1110 | } |
| 1111 | |
| 1112 | m = vm_page_alloc(&kernel_object, OFF_TO_IDX(addr + i), vmflags); |
| 1113 | |
| 1114 | /* |
| 1115 | * If the allocation failed we either return NULL or we retry. |
| 1116 | * |
| 1117 | * If M_WAITOK is specified we wait for more memory and retry. |
| 1118 | * If M_WAITOK is specified from a preemption we yield instead of |
| 1119 | * wait. Livelock will not occur because the interrupt thread |
| 1120 | * will not be preempting anyone the second time around after the |
| 1121 | * yield. |
| 1122 | */ |
| 1123 | if (m == NULL) { |
| 1124 | if (flags & M_WAITOK) { |
| 1125 | if (td->td_preempted) { |
| 1126 | vm_map_unlock(&kernel_map); |
| 1127 | lwkt_yield(); |
| 1128 | vm_map_lock(&kernel_map); |
| 1129 | } else { |
| 1130 | vm_map_unlock(&kernel_map); |
| 1131 | vm_wait(); |
| 1132 | vm_map_lock(&kernel_map); |
| 1133 | } |
| 1134 | i -= PAGE_SIZE; /* retry */ |
| 1135 | continue; |
| 1136 | } |
| 1137 | |
| 1138 | /* |
| 1139 | * We were unable to recover, cleanup and return NULL |
| 1140 | */ |
| 1141 | while (i != 0) { |
| 1142 | i -= PAGE_SIZE; |
| 1143 | m = vm_page_lookup(&kernel_object, OFF_TO_IDX(addr + i)); |
| 1144 | vm_page_free(m); |
| 1145 | } |
| 1146 | vm_map_delete(&kernel_map, addr, addr + size, &count); |
| 1147 | vm_map_unlock(&kernel_map); |
| 1148 | crit_exit(); |
| 1149 | vm_map_entry_release(count); |
| 1150 | rel_mplock(); |
| 1151 | return(NULL); |
| 1152 | } |
| 1153 | } |
| 1154 | |
| 1155 | /* |
| 1156 | * Success! |
| 1157 | * |
| 1158 | * Mark the map entry as non-pageable using a routine that allows us to |
| 1159 | * populate the underlying pages. |
| 1160 | */ |
| 1161 | vm_map_set_wired_quick(&kernel_map, addr, size, &count); |
| 1162 | crit_exit(); |
| 1163 | |
| 1164 | /* |
| 1165 | * Enter the pages into the pmap and deal with PG_ZERO and M_ZERO. |
| 1166 | */ |
| 1167 | for (i = 0; i < size; i += PAGE_SIZE) { |
| 1168 | vm_page_t m; |
| 1169 | |
| 1170 | m = vm_page_lookup(&kernel_object, OFF_TO_IDX(addr + i)); |
| 1171 | m->valid = VM_PAGE_BITS_ALL; |
| 1172 | vm_page_wire(m); |
| 1173 | vm_page_wakeup(m); |
| 1174 | pmap_enter(kernel_pmap, addr + i, m, VM_PROT_ALL, 1); |
| 1175 | if ((m->flags & PG_ZERO) == 0 && (flags & M_ZERO)) |
| 1176 | bzero((char *)addr + i, PAGE_SIZE); |
| 1177 | vm_page_flag_clear(m, PG_ZERO); |
| 1178 | vm_page_flag_set(m, PG_MAPPED | PG_WRITEABLE | PG_REFERENCED); |
| 1179 | } |
| 1180 | vm_map_unlock(&kernel_map); |
| 1181 | vm_map_entry_release(count); |
| 1182 | rel_mplock(); |
| 1183 | return((void *)addr); |
| 1184 | } |
| 1185 | |
| 1186 | /* |
| 1187 | * kmem_slab_free() |
| 1188 | * |
| 1189 | * MPALMOSTSAFE - acquires mplock |
| 1190 | */ |
| 1191 | static void |
| 1192 | kmem_slab_free(void *ptr, vm_size_t size) |
| 1193 | { |
| 1194 | get_mplock(); |
| 1195 | crit_enter(); |
| 1196 | vm_map_remove(&kernel_map, (vm_offset_t)ptr, (vm_offset_t)ptr + size); |
| 1197 | crit_exit(); |
| 1198 | rel_mplock(); |
| 1199 | } |
| 1200 | |