sys/vm/vm_meter.c

   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                 VM_OBJECT_LOCK(object);
 114                 vm_object_clear_flag(object, OBJ_ACTIVE);
 115                 VM_OBJECT_UNLOCK(object);
 116         }
 117         mtx_unlock(&vm_object_list_mtx);
 118         /*
 119          * Calculate process statistics.
 120          */
 121         sx_slock(&allproc_lock);
 122         FOREACH_PROC_IN_SYSTEM(p) {
 123                 if (p->p_flag & P_SYSTEM)
 124                         continue;
 125                 PROC_LOCK(p);
 126                 switch (p->p_state) {
 127                 case PRS_NEW:
 128                         PROC_UNLOCK(p);
 129                         continue;
 130                         break;
 131                 default:
 132                         FOREACH_THREAD_IN_PROC(p, td) {
 133                                 thread_lock(td);
 134                                 switch (td->td_state) {
 135                                 case TDS_INHIBITED:
 136                                         if (TD_IS_SWAPPED(td))
 137                                                 total.t_sw++;
 138                                         else if (TD_IS_SLEEPING(td) &&
 139                                             td->td_priority <= PZERO)
 140                                                 total.t_dw++;
 141                                         else
 142                                                 total.t_sl++;
 143                                         break;
 144
 145                                 case TDS_CAN_RUN:
 146                                         total.t_sw++;
 147                                         break;
 148                                 case TDS_RUNQ:
 149                                 case TDS_RUNNING:
 150                                         total.t_rq++;
 151                                         thread_unlock(td);
 152                                         continue;
 153                                 default:
 154                                         break;
 155                                 }
 156                                 thread_unlock(td);
 157                         }
 158                 }
 159                 PROC_UNLOCK(p);
 160                 /*
 161                  * Note active objects.
 162                  */
 163                 paging = 0;
 164                 vm = vmspace_acquire_ref(p);
 165                 if (vm == NULL)
 166                         continue;
 167                 map = &vm->vm_map;
 168                 vm_map_lock_read(map);
 169                 for (entry = map->header.next;
 170                     entry != &map->header; entry = entry->next) {
 171                         if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) ||
 172                             (object = entry->object.vm_object) == NULL)
 173                                 continue;
 174                         VM_OBJECT_LOCK(object);
 175                         vm_object_set_flag(object, OBJ_ACTIVE);
 176                         paging |= object->paging_in_progress;
 177                         VM_OBJECT_UNLOCK(object);
 178                 }
 179                 vm_map_unlock_read(map);
 180                 vmspace_free(vm);
 181                 if (paging)
 182                         total.t_pw++;
 183         }
 184         sx_sunlock(&allproc_lock);
 185         /*
 186          * Calculate object memory usage statistics.
 187          */
 188         mtx_lock(&vm_object_list_mtx);
 189         TAILQ_FOREACH(object, &vm_object_list, object_list) {
 190                 /*
 191                  * Perform unsynchronized reads on the object.  In
 192                  * this case, the lack of synchronization should not
 193                  * impair the accuracy of the reported statistics.
 194                  */
 195                 if (object->type == OBJT_DEVICE || object->type == OBJT_SG) {
 196                         /*
 197                          * Devices, like /dev/mem, will badly skew our totals.
 198                          */
 199                         continue;
 200                 }
 201                 if (object->ref_count == 0) {
 202                         /*
 203                          * Also skip unreferenced objects, including
 204                          * vnodes representing mounted file systems.
 205                          */
 206                         continue;
 207                 }
 208                 total.t_vm += object->size;
 209                 total.t_rm += object->resident_page_count;
 210                 if (object->flags & OBJ_ACTIVE) {
 211                         total.t_avm += object->size;
 212                         total.t_arm += object->resident_page_count;
 213                 }
 214                 if (object->shadow_count > 1) {
 215                         /* shared object */
 216                         total.t_vmshr += object->size;
 217                         total.t_rmshr += object->resident_page_count;
 218                         if (object->flags & OBJ_ACTIVE) {
 219                                 total.t_avmshr += object->size;
 220                                 total.t_armshr += object->resident_page_count;
 221                         }
 222                 }
 223         }
 224         mtx_unlock(&vm_object_list_mtx);
 225         total.t_free = cnt.v_free_count + cnt.v_cache_count;
 226         return (sysctl_handle_opaque(oidp, &total, sizeof(total), req));
 227 }
 228
 229 /*
 230  * vcnt() -     accumulate statistics from all cpus and the global cnt
 231  *              structure.
 232  *
 233  *      The vmmeter structure is now per-cpu as well as global.  Those
 234  *      statistics which can be kept on a per-cpu basis (to avoid cache
 235  *      stalls between cpus) can be moved to the per-cpu vmmeter.  Remaining
 236  *      statistics, such as v_free_reserved, are left in the global
 237  *      structure.
 238  *
 239  * (sysctl_oid *oidp, void *arg1, int arg2, struct sysctl_req *req)
 240  */
 241 static int
 242 vcnt(SYSCTL_HANDLER_ARGS)
 243 {
 244         int count = *(int *)arg1;
 245         int offset = (char *)arg1 - (char *)&cnt;
 246         int i;
 247
 248         CPU_FOREACH(i) {
 249                 struct pcpu *pcpu = pcpu_find(i);
 250                 count += *(int *)((char *)&pcpu->pc_cnt + offset);
 251         }
 252         return (SYSCTL_OUT(req, &count, sizeof(int)));
 253 }
 254
 255 SYSCTL_PROC(_vm, VM_TOTAL, vmtotal, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
 256     0, sizeof(struct vmtotal), vmtotal, "S,vmtotal",
 257     "System virtual memory statistics");
 258 SYSCTL_NODE(_vm, OID_AUTO, stats, CTLFLAG_RW, 0, "VM meter stats");
 259 static SYSCTL_NODE(_vm_stats, OID_AUTO, sys, CTLFLAG_RW, 0,
 260         "VM meter sys stats");
 261 static SYSCTL_NODE(_vm_stats, OID_AUTO, vm, CTLFLAG_RW, 0,
 262         "VM meter vm stats");
 263 SYSCTL_NODE(_vm_stats, OID_AUTO, misc, CTLFLAG_RW, 0, "VM meter misc stats");
 264
 265 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_swtch, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 266         &cnt.v_swtch, 0, vcnt, "IU", "Context switches");
 267 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_trap, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 268         &cnt.v_trap, 0, vcnt, "IU", "Traps");
 269 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_syscall, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 270         &cnt.v_syscall, 0, vcnt, "IU", "Syscalls");
 271 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_intr, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 272         &cnt.v_intr, 0, vcnt, "IU", "Hardware interrupts");
 273 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_soft, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 274         &cnt.v_soft, 0, vcnt, "IU", "Software interrupts");
 275 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vm_faults, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 276         &cnt.v_vm_faults, 0, vcnt, "IU", "VM faults");
 277 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cow_faults, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 278         &cnt.v_cow_faults, 0, vcnt, "IU", "COW faults");
 279 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cow_optim, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 280         &cnt.v_cow_optim, 0, vcnt, "IU", "Optimized COW faults");
 281 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_zfod, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 282         &cnt.v_zfod, 0, vcnt, "IU", "Zero fill");
 283 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_ozfod, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 284         &cnt.v_ozfod, 0, vcnt, "IU", "Optimized zero fill");
 285 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swapin, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 286         &cnt.v_swapin, 0, vcnt, "IU", "Swapin operations");
 287 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swapout, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 288         &cnt.v_swapout, 0, vcnt, "IU", "Swapout operations");
 289 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swappgsin, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 290         &cnt.v_swappgsin, 0, vcnt, "IU", "Swapin pages");
 291 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swappgsout, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 292         &cnt.v_swappgsout, 0, vcnt, "IU", "Swapout pages");
 293 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodein, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 294         &cnt.v_vnodein, 0, vcnt, "IU", "Vnodein operations");
 295 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodeout, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 296         &cnt.v_vnodeout, 0, vcnt, "IU", "Vnodeout operations");
 297 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodepgsin, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 298         &cnt.v_vnodepgsin, 0, vcnt, "IU", "Vnodein pages");
 299 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodepgsout, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 300         &cnt.v_vnodepgsout, 0, vcnt, "IU", "Vnodeout pages");
 301 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_intrans, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 302         &cnt.v_intrans, 0, vcnt, "IU", "In transit page blocking");
 303 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_reactivated, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 304         &cnt.v_reactivated, 0, vcnt, "IU", "Reactivated pages");
 305 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pdwakeups, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 306         &cnt.v_pdwakeups, 0, vcnt, "IU", "Pagedaemon wakeups");
 307 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pdpages, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 308         &cnt.v_pdpages, 0, vcnt, "IU", "Pagedaemon page scans");
 309 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_tcached, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 310         &cnt.v_tcached, 0, vcnt, "IU", "Total pages cached");
 311 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_dfree, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 312         &cnt.v_dfree, 0, vcnt, "IU", "");
 313 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pfree, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 314         &cnt.v_pfree, 0, vcnt, "IU", "");
 315 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_tfree, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 316         &cnt.v_tfree, 0, vcnt, "IU", "");
 317 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_page_size, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 318         &cnt.v_page_size, 0, vcnt, "IU", "");
 319 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_page_count, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 320         &cnt.v_page_count, 0, vcnt, "IU", "");
 321 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_reserved, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 322         &cnt.v_free_reserved, 0, vcnt, "IU", "");
 323 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_target, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 324         &cnt.v_free_target, 0, vcnt, "IU", "");
 325 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_min, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 326         &cnt.v_free_min, 0, vcnt, "IU", "");
 327 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_count, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 328         &cnt.v_free_count, 0, vcnt, "IU", "");
 329 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_wire_count, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 330         &cnt.v_wire_count, 0, vcnt, "IU", "");
 331 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_active_count, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 332         &cnt.v_active_count, 0, vcnt, "IU", "");
 333 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_inactive_target, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 334         &cnt.v_inactive_target, 0, vcnt, "IU", "");
 335 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_inactive_count, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 336         &cnt.v_inactive_count, 0, vcnt, "IU", "");
 337 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cache_count, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 338         &cnt.v_cache_count, 0, vcnt, "IU", "");
 339 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cache_min, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 340         &cnt.v_cache_min, 0, vcnt, "IU", "");
 341 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cache_max, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 342         &cnt.v_cache_max, 0, vcnt, "IU", "");
 343 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pageout_free_min, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 344         &cnt.v_pageout_free_min, 0, vcnt, "IU", "");
 345 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_interrupt_free_min, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 346         &cnt.v_interrupt_free_min, 0, vcnt, "IU", "");
 347 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_forks, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 348         &cnt.v_forks, 0, vcnt, "IU", "Number of fork() calls");
 349 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vforks, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 350         &cnt.v_vforks, 0, vcnt, "IU", "Number of vfork() calls");
 351 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_rforks, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 352         &cnt.v_rforks, 0, vcnt, "IU", "Number of rfork() calls");
 353 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_kthreads, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 354         &cnt.v_kthreads, 0, vcnt, "IU", "Number of fork() calls by kernel");
 355 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_forkpages, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 356         &cnt.v_forkpages, 0, vcnt, "IU", "VM pages affected by fork()");
 357 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vforkpages, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 358         &cnt.v_vforkpages, 0, vcnt, "IU", "VM pages affected by vfork()");
 359 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_rforkpages, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 360         &cnt.v_rforkpages, 0, vcnt, "IU", "VM pages affected by rfork()");
 361 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_kthreadpages, CTLTYPE_UINT|CTLFLAG_RD|CTLFLAG_MPSAFE,
 362         &cnt.v_kthreadpages, 0, vcnt, "IU", "VM pages affected by fork() by kernel");
 363
 364 SYSCTL_INT(_vm_stats_misc, OID_AUTO,
 365         zero_page_count, CTLFLAG_RD, &vm_page_zero_count, 0, "");