uvm_pglist.c revision 1.21
1 /* $NetBSD: uvm_pglist.c,v 1.21 2002/06/02 14:44:46 drochner Exp $ */ 2 3 /*- 4 * Copyright (c) 1997 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * uvm_pglist.c: pglist functions 42 */ 43 44 #include <sys/cdefs.h> 45 __KERNEL_RCSID(0, "$NetBSD: uvm_pglist.c,v 1.21 2002/06/02 14:44:46 drochner Exp $"); 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/malloc.h> 50 #include <sys/proc.h> 51 52 #include <uvm/uvm.h> 53 54 #ifdef VM_PAGE_ALLOC_MEMORY_STATS 55 #define STAT_INCR(v) (v)++ 56 #define STAT_DECR(v) do { \ 57 if ((v) == 0) \ 58 printf("%s:%d -- Already 0!\n", __FILE__, __LINE__); \ 59 else \ 60 (v)--; \ 61 } while (0) 62 u_long uvm_pglistalloc_npages; 63 #else 64 #define STAT_INCR(v) 65 #define STAT_DECR(v) 66 #endif 67 68 /* 69 * uvm_pglistalloc: allocate a list of pages 70 * 71 * => allocated pages are placed at the tail of rlist. rlist is 72 * assumed to be properly initialized by caller. 73 * => returns 0 on success or errno on failure 74 * => XXX: implementation allocates only a single segment, also 75 * might be able to better advantage of vm_physeg[]. 76 * => doesn't take into account clean non-busy pages on inactive list 77 * that could be used(?) 78 * => params: 79 * size the size of the allocation, rounded to page size. 80 * low the low address of the allowed allocation range. 81 * high the high address of the allowed allocation range. 82 * alignment memory must be aligned to this power-of-two boundary. 83 * boundary no segment in the allocation may cross this 84 * power-of-two boundary (relative to zero). 85 */ 86 87 static void uvm_pglist_add(struct vm_page *, struct pglist *); 88 static int uvm_pglistalloc_contig(psize_t, paddr_t, paddr_t, paddr_t, paddr_t, 89 struct pglist *); 90 static int uvm_pglistalloc_simple(psize_t, paddr_t, paddr_t, 91 struct pglist *, int); 92 93 static void 94 uvm_pglist_add(pg, rlist) 95 struct vm_page *pg; 96 struct pglist *rlist; 97 { 98 int free_list, color, pgflidx; 99 #ifdef DEBUG 100 struct vm_page *tp; 101 #endif 102 103 #if PGFL_NQUEUES != 2 104 #error uvm_pglistalloc needs to be updated 105 #endif 106 107 free_list = uvm_page_lookup_freelist(pg); 108 color = VM_PGCOLOR_BUCKET(pg); 109 pgflidx = (pg->flags & PG_ZERO) ? PGFL_ZEROS : PGFL_UNKNOWN; 110 #ifdef DEBUG 111 for (tp = TAILQ_FIRST(&uvm.page_free[ 112 free_list].pgfl_buckets[color].pgfl_queues[pgflidx]); 113 tp != NULL; 114 tp = TAILQ_NEXT(tp, pageq)) { 115 if (tp == pg) 116 break; 117 } 118 if (tp == NULL) 119 panic("uvm_pglistalloc: page not on freelist"); 120 #endif 121 TAILQ_REMOVE(&uvm.page_free[free_list].pgfl_buckets[ 122 color].pgfl_queues[pgflidx], pg, pageq); 123 uvmexp.free--; 124 if (pg->flags & PG_ZERO) 125 uvmexp.zeropages--; 126 pg->flags = PG_CLEAN; 127 pg->pqflags = 0; 128 pg->uobject = NULL; 129 pg->uanon = NULL; 130 TAILQ_INSERT_TAIL(rlist, pg, pageq); 131 STAT_INCR(uvm_pglistalloc_npages); 132 } 133 134 static int 135 uvm_pglistalloc_contig(size, low, high, alignment, boundary, rlist) 136 psize_t size; 137 paddr_t low, high, alignment, boundary; 138 struct pglist *rlist; 139 { 140 paddr_t try, idxpa, lastidxpa; 141 int psi; 142 struct vm_page *pgs; 143 int s, tryidx, idx, end, error; 144 u_long pagemask; 145 146 if (boundary != 0 && boundary < size) 147 return (EINVAL); 148 pagemask = ~(boundary - 1); 149 150 /* Default to "lose". */ 151 error = ENOMEM; 152 153 /* 154 * Block all memory allocation and lock the free list. 155 */ 156 157 s = uvm_lock_fpageq(); 158 159 /* Are there even any free pages? */ 160 if (uvmexp.free <= (uvmexp.reserve_pagedaemon + uvmexp.reserve_kernel)) 161 goto out; 162 163 for (try = low;; try += alignment) { 164 if (try + size > high) { 165 166 /* 167 * We've run past the allowable range. 168 */ 169 170 goto out; 171 } 172 173 /* 174 * Make sure this is a managed physical page. 175 */ 176 177 if ((psi = vm_physseg_find(atop(try), &idx)) == -1) 178 continue; /* managed? */ 179 if (vm_physseg_find(atop(try + size), NULL) != psi) 180 continue; /* end must be in this segment */ 181 tryidx = idx; 182 end = idx + (size / PAGE_SIZE); 183 pgs = vm_physmem[psi].pgs; 184 185 /* 186 * Found a suitable starting page. See of the range is free. 187 */ 188 189 for (; idx < end; idx++) { 190 if (VM_PAGE_IS_FREE(&pgs[idx]) == 0) { 191 break; 192 } 193 idxpa = VM_PAGE_TO_PHYS(&pgs[idx]); 194 if (idx > tryidx) { 195 lastidxpa = VM_PAGE_TO_PHYS(&pgs[idx - 1]); 196 if ((lastidxpa + PAGE_SIZE) != idxpa) { 197 198 /* 199 * Region not contiguous. 200 */ 201 202 break; 203 } 204 if (boundary != 0 && 205 ((lastidxpa ^ idxpa) & pagemask) != 0) { 206 207 /* 208 * Region crosses boundary. 209 */ 210 211 break; 212 } 213 } 214 } 215 if (idx == end) { 216 break; 217 } 218 } 219 220 /* 221 * we have a chunk of memory that conforms to the requested constraints. 222 */ 223 idx = tryidx; 224 while (idx < end) { 225 uvm_pglist_add(&pgs[idx++], rlist); 226 } 227 error = 0; 228 229 out: 230 /* 231 * check to see if we need to generate some free pages waking 232 * the pagedaemon. 233 */ 234 235 UVM_KICK_PDAEMON(); 236 uvm_unlock_fpageq(s); 237 return (error); 238 } 239 240 static int 241 uvm_pglistalloc_simple(size, low, high, rlist, waitok) 242 psize_t size; 243 paddr_t low, high; 244 struct pglist *rlist; 245 int waitok; 246 { 247 psize_t try; 248 int psi; 249 struct vm_page *pg; 250 int s, todo, idx, error; 251 252 /* Default to "lose". */ 253 error = ENOMEM; 254 255 todo = size / PAGE_SIZE; 256 257 again: 258 /* 259 * Block all memory allocation and lock the free list. 260 */ 261 262 s = uvm_lock_fpageq(); 263 264 /* Are there even any free pages? */ 265 if (uvmexp.free <= (uvmexp.reserve_pagedaemon + uvmexp.reserve_kernel)) 266 goto out; 267 268 for (try = low; try < high; try += PAGE_SIZE) { 269 270 /* 271 * Make sure this is a managed physical page. 272 */ 273 274 if ((psi = vm_physseg_find(atop(try), &idx)) == -1) 275 continue; /* managed? */ 276 pg = &vm_physmem[psi].pgs[idx]; 277 if (VM_PAGE_IS_FREE(pg) == 0) 278 continue; 279 280 uvm_pglist_add(pg, rlist); 281 if (--todo == 0) { 282 error = 0; 283 goto out; 284 } 285 } 286 287 out: 288 /* 289 * check to see if we need to generate some free pages waking 290 * the pagedaemon. 291 */ 292 293 UVM_KICK_PDAEMON(); 294 uvm_unlock_fpageq(s); 295 if (error) { 296 if (waitok) { 297 /* XXX perhaps some time limitation? */ 298 #ifdef DEBUG 299 printf("pglistalloc waiting\n"); 300 #endif 301 uvm_wait("pglalloc"); 302 goto again; 303 } else 304 uvm_pglistfree(rlist); 305 } 306 return (error); 307 } 308 309 int 310 uvm_pglistalloc(size, low, high, alignment, boundary, rlist, nsegs, waitok) 311 psize_t size; 312 paddr_t low, high, alignment, boundary; 313 struct pglist *rlist; 314 int nsegs, waitok; 315 { 316 int res; 317 318 KASSERT((alignment & (alignment - 1)) == 0); 319 KASSERT((boundary & (boundary - 1)) == 0); 320 321 /* 322 * Our allocations are always page granularity, so our alignment 323 * must be, too. 324 */ 325 if (alignment < PAGE_SIZE) 326 alignment = PAGE_SIZE; 327 size = round_page(size); 328 low = roundup(low, alignment); 329 330 TAILQ_INIT(rlist); 331 332 if ((nsegs < size / PAGE_SIZE) || (alignment != PAGE_SIZE) 333 || (boundary != 0)) 334 res = uvm_pglistalloc_contig(size, low, high, alignment, 335 boundary, rlist); 336 else 337 res = uvm_pglistalloc_simple(size, low, high, rlist, waitok); 338 339 return (res); 340 } 341 342 /* 343 * uvm_pglistfree: free a list of pages 344 * 345 * => pages should already be unmapped 346 */ 347 348 void 349 uvm_pglistfree(list) 350 struct pglist *list; 351 { 352 struct vm_page *pg; 353 int s; 354 355 /* 356 * Lock the free list and free each page. 357 */ 358 359 s = uvm_lock_fpageq(); 360 while ((pg = TAILQ_FIRST(list)) != NULL) { 361 KASSERT((pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) == 0); 362 TAILQ_REMOVE(list, pg, pageq); 363 pg->pqflags = PQ_FREE; 364 TAILQ_INSERT_TAIL(&uvm.page_free[uvm_page_lookup_freelist(pg)]. 365 pgfl_buckets[VM_PGCOLOR_BUCKET(pg)]. 366 pgfl_queues[PGFL_UNKNOWN], pg, pageq); 367 uvmexp.free++; 368 if (uvmexp.zeropages < UVM_PAGEZERO_TARGET) 369 uvm.page_idle_zero = vm_page_zero_enable; 370 STAT_DECR(uvm_pglistalloc_npages); 371 } 372 uvm_unlock_fpageq(s); 373 } 374
Indexes created Sun Sep 21 16:09:51 GMT 2025