1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. 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 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)vm_meter.c 8.4 (Berkeley) 1/4/94 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/kernel.h> 38 #include <sys/lock.h> 39 #include <sys/mutex.h> 40 #include <sys/proc.h> 41 #include <sys/resource.h> 42 #include <sys/sx.h> 43 #include <sys/vmmeter.h> 44 #include <sys/smp.h> 45 46 #include <vm/vm.h> 47 #include <vm/vm_page.h> 48 #include <vm/vm_extern.h> 49 #include <vm/vm_param.h> 50 #include <vm/pmap.h> 51 #include <vm/vm_map.h> 52 #include <vm/vm_object.h> 53 #include <sys/sysctl.h> 54 55 struct vmmeter cnt; 56 57 SYSCTL_UINT(_vm, VM_V_FREE_MIN, v_free_min, 58 CTLFLAG_RW, &cnt.v_free_min, 0, ""); 59 SYSCTL_UINT(_vm, VM_V_FREE_TARGET, v_free_target, 60 CTLFLAG_RW, &cnt.v_free_target, 0, ""); 61 SYSCTL_UINT(_vm, VM_V_FREE_RESERVED, v_free_reserved, 62 CTLFLAG_RW, &cnt.v_free_reserved, 0, ""); 63 SYSCTL_UINT(_vm, VM_V_INACTIVE_TARGET, v_inactive_target, 64 CTLFLAG_RW, &cnt.v_inactive_target, 0, ""); 65 SYSCTL_UINT(_vm, VM_V_CACHE_MIN, v_cache_min, 66 CTLFLAG_RW, &cnt.v_cache_min, 0, ""); 67 SYSCTL_UINT(_vm, VM_V_CACHE_MAX, v_cache_max, 68 CTLFLAG_RW, &cnt.v_cache_max, 0, ""); 69 SYSCTL_UINT(_vm, VM_V_PAGEOUT_FREE_MIN, v_pageout_free_min, 70 CTLFLAG_RW, &cnt.v_pageout_free_min, 0, ""); 71 SYSCTL_UINT(_vm, OID_AUTO, v_free_severe, 72 CTLFLAG_RW, &cnt.v_free_severe, 0, ""); 73 74 static int 75 sysctl_vm_loadavg(SYSCTL_HANDLER_ARGS) 76 { 77 78 #ifdef SCTL_MASK32 79 u_int32_t la[4]; 80 81 if (req->flags & SCTL_MASK32) { 82 la[0] = averunnable.ldavg[0]; 83 la[1] = averunnable.ldavg[1]; 84 la[2] = averunnable.ldavg[2]; 85 la[3] = averunnable.fscale; 86 return SYSCTL_OUT(req, la, sizeof(la)); 87 } else 88 #endif 89 return SYSCTL_OUT(req, &averunnable, sizeof(averunnable)); 90 } 91 SYSCTL_PROC(_vm, VM_LOADAVG, loadavg, CTLTYPE_STRUCT | CTLFLAG_RD | 92 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_loadavg, "S,loadavg", 93 "Machine loadaverage history"); 94 95 static int 96 vmtotal(SYSCTL_HANDLER_ARGS) 97 { 98 struct proc *p; 99 struct vmtotal total; 100 vm_map_entry_t entry; 101 vm_object_t object; 102 vm_map_t map; 103 int paging; 104 struct thread *td; 105 struct vmspace *vm; 106 107 bzero(&total, sizeof(total)); 108 /* 109 * Mark all objects as inactive. 110 */ 111 mtx_lock(&vm_object_list_mtx); 112 TAILQ_FOREACH(object, &vm_object_list, object_list) { 113 if (!VM_OBJECT_TRYLOCK(object)) { 114 /* 115 * Avoid a lock-order reversal. Consequently, 116 * the reported number of active pages may be 117 * greater than the actual number. 118 */ 119 continue; 120 } 121 vm_object_clear_flag(object, OBJ_ACTIVE); 122 VM_OBJECT_UNLOCK(object); 123 } 124 mtx_unlock(&vm_object_list_mtx); 125 /* 126 * Calculate process statistics. 127 */ 128 sx_slock(&allproc_lock); 129 FOREACH_PROC_IN_SYSTEM(p) { 130 if (p->p_flag & P_SYSTEM) 131 continue; 132 PROC_LOCK(p); 133 switch (p->p_state) { 134 case PRS_NEW: 135 PROC_UNLOCK(p); 136 continue; 137 break; 138 default: 139 FOREACH_THREAD_IN_PROC(p, td) { 140 thread_lock(td); 141 switch (td->td_state) { 142 case TDS_INHIBITED: 143 if (TD_IS_SWAPPED(td)) 144 total.t_sw++; 145 else if (TD_IS_SLEEPING(td) && 146 td->td_priority <= PZERO) 147 total.t_dw++; 148 else 149 total.t_sl++; 150 break; 151 152 case TDS_CAN_RUN: 153 total.t_sw++; 154 break; 155 case TDS_RUNQ: 156 case TDS_RUNNING: 157 total.t_rq++; 158 thread_unlock(td); 159 continue; 160 default: 161 break; 162 } 163 thread_unlock(td); 164 } 165 } 166 PROC_UNLOCK(p); 167 /* 168 * Note active objects. 169 */ 170 paging = 0; 171 vm = vmspace_acquire_ref(p); 172 if (vm == NULL) 173 continue; 174 map = &vm->vm_map; 175 vm_map_lock_read(map); 176 for (entry = map->header.next; 177 entry != &map->header; entry = entry->next) { 178 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 179 (object = entry->object.vm_object) == NULL) 180 continue; 181 VM_OBJECT_LOCK(object); 182 vm_object_set_flag(object, OBJ_ACTIVE); 183 paging |= object->paging_in_progress; 184 VM_OBJECT_UNLOCK(object); 185 } 186 vm_map_unlock_read(map); 187 vmspace_free(vm); 188 if (paging) 189 total.t_pw++; 190 } 191 sx_sunlock(&allproc_lock); 192 /* 193 * Calculate object memory usage statistics. 194 */ 195 mtx_lock(&vm_object_list_mtx); 196 TAILQ_FOREACH(object, &vm_object_list, object_list) { 197 /* 198 * Perform unsynchronized reads on the object to avoid 199 * a lock-order reversal. In this case, the lack of 200 * synchronization should not impair the accuracy of 201 * the reported statistics. 202 */ 203 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { 204 /* 205 * Devices, like /dev/mem, will badly skew our totals. 206 */ 207 continue; 208 } 209 if (object->ref_count == 0) { 210 /* 211 * Also skip unreferenced objects, including 212 * vnodes representing mounted file systems. 213 */ 214 continue; 215 } 216 total.t_vm += object->size; 217 total.t_rm += object->resident_page_count; 218 if (object->flags & OBJ_ACTIVE) { 219 total.t_avm += object->size; 220 total.t_arm += object->resident_page_count; 221 } 222 if (object->shadow_count > 1) { 223 /* shared object */ 224 total.t_vmshr += object->size; 225 total.t_rmshr += object->resident_page_count; 226 if (object->flags & OBJ_ACTIVE) { 227 total.t_avmshr += object->size; 228 total.t_armshr += object->resident_page_count; 229 } 230 } 231 } 232 mtx_unlock(&vm_object_list_mtx); 233 total.t_free = cnt.v_free_count + cnt.v_cache_count; 234 return (sysctl_handle_opaque(oidp, &total, sizeof(total), req)); 235 } 236 237 /* 238 * vcnt() - accumulate statistics from all cpus and the global cnt 239 * structure. 240 * 241 * The vmmeter structure is now per-cpu as well as global. Those 242 * statistics which can be kept on a per-cpu basis (to avoid cache 243 * stalls between cpus) can be moved to the per-cpu vmmeter. Remaining 244 * statistics, such as v_free_reserved, are left in the global 245 * structure. 246 * 247 * (sysctl_oid *oidp, void *arg1, int arg2, struct sysctl_req *req) 248 */ 249 static int 250 vcnt(SYSCTL_HANDLER_ARGS) 251 { 252 int count = *(int *)arg1; 253 int offset = (char *)arg1 - (char *)&cnt; 254 int i; 255 256 CPU_FOREACH(i) { 257 struct pcpu *pcpu = pcpu_find(i); 258 count += *(int *)((char *)&pcpu->pc_cnt + offset); 259 } 260 return (SYSCTL_OUT(req, &count, sizeof(int))); 261 } 262 263 SYSCTL_PROC(_vm, VM_TOTAL, vmtotal, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 264 0, sizeof(struct vmtotal), vmtotal, "S,vmtotal", 265 "System virtual memory statistics"); 266 SYSCTL_NODE(_vm, OID_AUTO, stats, CTLFLAG_RW, 0, "VM meter stats"); 267 static SYSCTL_NODE(_vm_stats, OID_AUTO, sys, CTLFLAG_RW, 0, 268 "VM meter sys stats"); 269 static SYSCTL_NODE(_vm_stats, OID_AUTO, vm, CTLFLAG_RW, 0, 270 "VM meter vm stats"); 271 SYSCTL_NODE(_vm_stats, OID_AUTO, misc, CTLFLAG_RW, 0, "VM meter misc stats"); 272 273 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_swtch, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 274 &cnt.v_swtch, 0, vcnt, "IU", "Context switches"); 275 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_trap, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 276 &cnt.v_trap, 0, vcnt, "IU", "Traps"); 277 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_syscall, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 278 &cnt.v_syscall, 0, vcnt, "IU", "Syscalls"); 279 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_intr, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 280 &cnt.v_intr, 0, vcnt, "IU", "Hardware interrupts"); 281 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_soft, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 282 &cnt.v_soft, 0, vcnt, "IU", "Software interrupts"); 283 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vm_faults, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 284 &cnt.v_vm_faults, 0, vcnt, "IU", "VM faults"); 285 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cow_faults, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 286 &cnt.v_cow_faults, 0, vcnt, "IU", "COW faults"); 287 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cow_optim, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 288 &cnt.v_cow_optim, 0, vcnt, "IU", "Optimized COW faults"); 289 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_zfod, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 290 &cnt.v_zfod, 0, vcnt, "IU", "Zero fill"); 291 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_ozfod, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 292 &cnt.v_ozfod, 0, vcnt, "IU", "Optimized zero fill"); 293 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swapin, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 294 &cnt.v_swapin, 0, vcnt, "IU", "Swapin operations"); 295 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swapout, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 296 &cnt.v_swapout, 0, vcnt, "IU", "Swapout operations"); 297 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swappgsin, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 298 &cnt.v_swappgsin, 0, vcnt, "IU", "Swapin pages"); 299 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swappgsout, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 300 &cnt.v_swappgsout, 0, vcnt, "IU", "Swapout pages"); 301 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodein, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 302 &cnt.v_vnodein, 0, vcnt, "IU", "Vnodein operations"); 303 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodeout, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 304 &cnt.v_vnodeout, 0, vcnt, "IU", "Vnodeout operations"); 305 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodepgsin, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 306 &cnt.v_vnodepgsin, 0, vcnt, "IU", "Vnodein pages"); 307 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodepgsout, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 308 &cnt.v_vnodepgsout, 0, vcnt, "IU", "Vnodeout pages"); 309 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_intrans, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 310 &cnt.v_intrans, 0, vcnt, "IU", "In transit page blocking"); 311 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_reactivated, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 312 &cnt.v_reactivated, 0, vcnt, "IU", "Reactivated pages"); 313 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pdwakeups, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 314 &cnt.v_pdwakeups, 0, vcnt, "IU", "Pagedaemon wakeups"); 315 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pdpages, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 316 &cnt.v_pdpages, 0, vcnt, "IU", "Pagedaemon page scans"); 317 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_tcached, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 318 &cnt.v_tcached, 0, vcnt, "IU", "Total pages cached"); 319 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_dfree, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 320 &cnt.v_dfree, 0, vcnt, "IU", ""); 321 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pfree, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 322 &cnt.v_pfree, 0, vcnt, "IU", ""); 323 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_tfree, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 324 &cnt.v_tfree, 0, vcnt, "IU", ""); 325 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_page_size, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 326 &cnt.v_page_size, 0, vcnt, "IU", ""); 327 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_page_count, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 328 &cnt.v_page_count, 0, vcnt, "IU", ""); 329 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_reserved, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 330 &cnt.v_free_reserved, 0, vcnt, "IU", ""); 331 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_target, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 332 &cnt.v_free_target, 0, vcnt, "IU", ""); 333 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_min, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 334 &cnt.v_free_min, 0, vcnt, "IU", ""); 335 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_count, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 336 &cnt.v_free_count, 0, vcnt, "IU", ""); 337 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_wire_count, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 338 &cnt.v_wire_count, 0, vcnt, "IU", ""); 339 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_active_count, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 340 &cnt.v_active_count, 0, vcnt, "IU", ""); 341 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_inactive_target, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 342 &cnt.v_inactive_target, 0, vcnt, "IU", ""); 343 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_inactive_count, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 344 &cnt.v_inactive_count, 0, vcnt, "IU", ""); 345 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cache_count, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 346 &cnt.v_cache_count, 0, vcnt, "IU", ""); 347 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cache_min, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 348 &cnt.v_cache_min, 0, vcnt, "IU", ""); 349 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cache_max, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 350 &cnt.v_cache_max, 0, vcnt, "IU", ""); 351 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pageout_free_min, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 352 &cnt.v_pageout_free_min, 0, vcnt, "IU", ""); 353 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_interrupt_free_min, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 354 &cnt.v_interrupt_free_min, 0, vcnt, "IU", ""); 355 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_forks, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 356 &cnt.v_forks, 0, vcnt, "IU", "Number of fork() calls"); 357 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vforks, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 358 &cnt.v_vforks, 0, vcnt, "IU", "Number of vfork() calls"); 359 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_rforks, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 360 &cnt.v_rforks, 0, vcnt, "IU", "Number of rfork() calls"); 361 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_kthreads, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 362 &cnt.v_kthreads, 0, vcnt, "IU", "Number of fork() calls by kernel"); 363 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_forkpages, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 364 &cnt.v_forkpages, 0, vcnt, "IU", "VM pages affected by fork()"); 365 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vforkpages, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 366 &cnt.v_vforkpages, 0, vcnt, "IU", "VM pages affected by vfork()"); 367 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_rforkpages, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 368 &cnt.v_rforkpages, 0, vcnt, "IU", "VM pages affected by rfork()"); 369 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_kthreadpages, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE, 370 &cnt.v_kthreadpages, 0, vcnt, "IU", "VM pages affected by fork() by kernel"); 371 372 SYSCTL_INT(_vm_stats_misc, OID_AUTO, 373 zero_page_count, CTLFLAG_RD, &vm_page_zero_count, 0, ""); 374