1 /* 2 * Copyright (c) 2003 Matthew Dillon <dillon@backplane.com> 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, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $DragonFly: src/sys/kern/kern_mpipe.c,v 1.7 2004/06/04 06:56:12 dillon Exp $ 27 */ 28 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/kernel.h> 32 #include <sys/slaballoc.h> 33 #include <sys/mbuf.h> 34 #include <sys/vmmeter.h> 35 #include <sys/lock.h> 36 #include <sys/thread.h> 37 #include <sys/globaldata.h> 38 #include <sys/mpipe.h> 39 40 #include <sys/thread2.h> 41 42 #define arysize(ary) (sizeof(ary)/sizeof((ary)[0])) 43 44 static MALLOC_DEFINE(M_MPIPEARY, "MPipe Array", "Auxillary MPIPE structure"); 45 46 /* 47 * Initialize a malloc pipeline for the specified malloc type and allocation 48 * size. Create an array to cache up to nom_count buffers and preallocate 49 * them. 50 */ 51 void 52 mpipe_init(malloc_pipe_t mpipe, malloc_type_t type, int bytes, 53 int nnom, int nmax, 54 int mpflags, void (*deconstruct)(struct malloc_pipe *, void *)) 55 { 56 int n; 57 58 if (nnom < 1) 59 nnom = 1; 60 if (nmax < 0) 61 nmax = 0x7FFF0000; /* some very large number */ 62 if (nmax < nnom) 63 nmax = nnom; 64 bzero(mpipe, sizeof(struct malloc_pipe)); 65 mpipe->type = type; 66 mpipe->bytes = bytes; 67 mpipe->mpflags = mpflags; 68 mpipe->deconstruct = deconstruct; 69 if ((mpflags & MPF_NOZERO) == 0) 70 mpipe->mflags |= M_ZERO; 71 if (mpflags & MPF_INT) 72 mpipe->mflags |= M_USE_RESERVE | M_USE_INTERRUPT_RESERVE; 73 mpipe->ary_count = nnom; 74 mpipe->max_count = nmax; 75 mpipe->array = malloc(nnom * sizeof(mpipe->array[0]), M_MPIPEARY, 76 M_WAITOK | M_ZERO); 77 78 while (mpipe->free_count < nnom) { 79 n = mpipe->free_count; 80 mpipe->array[n] = malloc(bytes, mpipe->type, M_WAITOK | mpipe->mflags); 81 ++mpipe->free_count; 82 ++mpipe->total_count; 83 } 84 } 85 86 /* 87 * Destroy a previously initialized mpipe. This routine can also safely be 88 * called on an uninitialized mpipe structure if it was zero'd or mpipe_done() 89 * was previously called on it. 90 */ 91 void 92 mpipe_done(malloc_pipe_t mpipe) 93 { 94 void *buf; 95 int n; 96 97 KKASSERT(mpipe->free_count == mpipe->total_count); /* no outstanding mem */ 98 for (n = mpipe->free_count - 1; n >= 0; --n) { 99 buf = mpipe->array[n]; 100 mpipe->array[n] = NULL; 101 KKASSERT(buf != NULL); 102 if (mpipe->deconstruct) 103 mpipe->deconstruct(mpipe, buf); 104 free(buf, mpipe->type); 105 } 106 mpipe->free_count = 0; 107 mpipe->total_count = 0; 108 if (mpipe->array) { 109 free(mpipe->array, M_MPIPEARY); 110 mpipe->array = NULL; 111 } 112 } 113 114 /* 115 * Allocate an entry, nominally non-blocking. The allocation is guarenteed 116 * to return non-NULL up to the nominal count after which it may return NULL. 117 * Note that the implementation is defined to be allowed to block for short 118 * periods of time. Use mpipe_alloc_waitok() to guarentee the allocation. 119 */ 120 void * 121 mpipe_alloc_nowait(malloc_pipe_t mpipe) 122 { 123 void *buf; 124 int n; 125 126 crit_enter(); 127 if ((n = mpipe->free_count) != 0) { 128 /* 129 * Use a free entry if it exists. 130 */ 131 --n; 132 buf = mpipe->array[n]; 133 mpipe->array[n] = NULL; /* sanity check, not absolutely needed */ 134 mpipe->free_count = n; 135 } else if (mpipe->total_count >= mpipe->max_count) { 136 /* 137 * Return NULL if we have hit our limit 138 */ 139 buf = NULL; 140 } else { 141 /* 142 * Otherwise try to malloc() non-blocking. 143 */ 144 buf = malloc(mpipe->bytes, mpipe->type, M_NOWAIT | mpipe->mflags); 145 if (buf) 146 ++mpipe->total_count; 147 } 148 crit_exit(); 149 return(buf); 150 } 151 152 /* 153 * Allocate an entry, block until the allocation succeeds. This may cause 154 * us to block waiting for a prior allocation to be freed. 155 */ 156 void * 157 mpipe_alloc_waitok(malloc_pipe_t mpipe) 158 { 159 void *buf; 160 int n; 161 int mfailed; 162 163 crit_enter(); 164 mfailed = 0; 165 for (;;) { 166 if ((n = mpipe->free_count) != 0) { 167 /* 168 * Use a free entry if it exists. 169 */ 170 --n; 171 buf = mpipe->array[n]; 172 mpipe->array[n] = NULL; 173 mpipe->free_count = n; 174 break; 175 } 176 if (mpipe->total_count >= mpipe->max_count || mfailed) { 177 /* 178 * Block if we have hit our limit 179 */ 180 mpipe->pending = 1; 181 tsleep(mpipe, 0, "mpipe1", 0); 182 continue; 183 } 184 /* 185 * Otherwise try to malloc() non-blocking. If that fails loop to 186 * recheck, and block instead of trying to malloc() again. 187 */ 188 buf = malloc(mpipe->bytes, mpipe->type, M_NOWAIT | mpipe->mflags); 189 if (buf) { 190 ++mpipe->total_count; 191 break; 192 } 193 mfailed = 1; 194 } 195 crit_exit(); 196 return(buf); 197 } 198 199 /* 200 * Free an entry, unblock any waiters. Allow NULL. 201 */ 202 void 203 mpipe_free(malloc_pipe_t mpipe, void *buf) 204 { 205 int n; 206 207 if (buf == NULL) 208 return; 209 210 crit_enter(); 211 if ((n = mpipe->free_count) < mpipe->ary_count) { 212 /* 213 * Free slot available in free array (LIFO) 214 */ 215 mpipe->array[n] = buf; 216 ++mpipe->free_count; 217 if ((mpipe->mpflags & (MPF_CACHEDATA|MPF_NOZERO)) == 0) 218 bzero(buf, mpipe->bytes); 219 crit_exit(); 220 221 /* 222 * Wakeup anyone blocked in mpipe_alloc_*(). 223 */ 224 if (mpipe->pending) { 225 mpipe->pending = 0; 226 wakeup(mpipe); 227 } 228 } else { 229 /* 230 * All the free slots are full, free the buffer directly. 231 */ 232 --mpipe->total_count; 233 KKASSERT(mpipe->total_count >= mpipe->free_count); 234 if (mpipe->deconstruct) 235 mpipe->deconstruct(mpipe, buf); 236 crit_exit(); 237 free(buf, mpipe->type); 238 } 239 } 240 241