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 1.5 2004/03/29 16:22:21 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 mpipe->ary_count = nnom; 72 mpipe->max_count = nmax; 73 mpipe->array = malloc(nnom * sizeof(mpipe->array[0]), M_MPIPEARY, 74 M_WAITOK | M_ZERO); 75 76 while (mpipe->free_count < nnom) { 77 n = mpipe->free_count; 78 mpipe->array[n] = malloc(bytes, mpipe->type, M_WAITOK | mpipe->mflags); 79 ++mpipe->free_count; 80 ++mpipe->total_count; 81 } 82 } 83 84 void 85 mpipe_done(malloc_pipe_t mpipe) 86 { 87 void *buf; 88 int n; 89 90 KKASSERT(mpipe->free_count == mpipe->total_count); /* no outstanding mem */ 91 while (--mpipe->free_count >= 0) { 92 n = mpipe->free_count; 93 buf = mpipe->array[n]; 94 mpipe->array[n] = NULL; 95 KKASSERT(buf != NULL); 96 --mpipe->total_count; 97 if (mpipe->deconstruct) 98 mpipe->deconstruct(mpipe, buf); 99 free(buf, mpipe->type); 100 } 101 } 102 103 /* 104 * Allocate an entry, nominally non-blocking. The allocation is guarenteed 105 * to return non-NULL up to the nominal count after which it may return NULL. 106 * Note that the implementation is defined to be allowed to block for short 107 * periods of time. Use mpipe_alloc_waitok() to guarentee the allocation. 108 */ 109 void * 110 mpipe_alloc_nowait(malloc_pipe_t mpipe) 111 { 112 void *buf; 113 int n; 114 115 crit_enter(); 116 if ((n = mpipe->free_count) != 0) { 117 /* 118 * Use a free entry if it exists. 119 */ 120 --n; 121 buf = mpipe->array[n]; 122 mpipe->array[n] = NULL; /* sanity check, not absolutely needed */ 123 mpipe->free_count = n; 124 } else if (mpipe->total_count >= mpipe->max_count) { 125 /* 126 * Return NULL if we have hit our limit 127 */ 128 buf = NULL; 129 } else { 130 /* 131 * Otherwise try to malloc() non-blocking. 132 */ 133 buf = malloc(mpipe->bytes, mpipe->type, M_NOWAIT | mpipe->mflags); 134 if (buf) 135 ++mpipe->total_count; 136 } 137 crit_exit(); 138 return(buf); 139 } 140 141 /* 142 * Allocate an entry, block until the allocation succeeds. This may cause 143 * us to block waiting for a prior allocation to be freed. 144 */ 145 void * 146 mpipe_alloc_waitok(malloc_pipe_t mpipe) 147 { 148 void *buf; 149 int n; 150 int mfailed; 151 152 crit_enter(); 153 mfailed = 0; 154 for (;;) { 155 if ((n = mpipe->free_count) != 0) { 156 /* 157 * Use a free entry if it exists. 158 */ 159 --n; 160 buf = mpipe->array[n]; 161 mpipe->array[n] = NULL; 162 mpipe->free_count = n; 163 break; 164 } 165 if (mpipe->total_count >= mpipe->max_count || mfailed) { 166 /* 167 * Block if we have hit our limit 168 */ 169 mpipe->pending = 1; 170 tsleep(mpipe, 0, "mpipe1", 0); 171 continue; 172 } 173 /* 174 * Otherwise try to malloc() non-blocking. If that fails loop to 175 * recheck, and block instead of trying to malloc() again. 176 */ 177 buf = malloc(mpipe->bytes, mpipe->type, M_NOWAIT | mpipe->mflags); 178 if (buf) { 179 ++mpipe->total_count; 180 break; 181 } 182 mfailed = 1; 183 } 184 crit_exit(); 185 return(buf); 186 } 187 188 /* 189 * Free an entry, unblock any waiters. Allow NULL. 190 */ 191 void 192 mpipe_free(malloc_pipe_t mpipe, void *buf) 193 { 194 int n; 195 196 if (buf == NULL) 197 return; 198 199 crit_enter(); 200 if ((n = mpipe->free_count) < mpipe->ary_count) { 201 /* 202 * Free slot available in free array (LIFO) 203 */ 204 mpipe->array[n] = buf; 205 ++mpipe->free_count; 206 if ((mpipe->mpflags & (MPF_CACHEDATA|MPF_NOZERO)) == 0) 207 bzero(buf, mpipe->bytes); 208 crit_exit(); 209 210 /* 211 * Wakeup anyone blocked in mpipe_alloc_*(). 212 */ 213 if (mpipe->pending) { 214 mpipe->pending = 0; 215 wakeup(mpipe); 216 } 217 } else { 218 /* 219 * All the free slots are full, free the buffer directly. 220 */ 221 --mpipe->total_count; 222 KKASSERT(mpipe->total_count >= mpipe->free_count); 223 if (mpipe->deconstruct) 224 mpipe->deconstruct(mpipe, buf); 225 crit_exit(); 226 free(buf, mpipe->type); 227 } 228 } 229 230