6/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 /*
  56  * Virtual memory MPSAFE temporary workarounds.
  57  */
  58 #if !defined(__arm__) && !defined(__powerpc__)
  59 int debug_mpsafevm = 1;
  60 #else
  61 int debug_mpsafevm;
  62 #endif
  63 TUNABLE_INT("debug.mpsafevm", &debug_mpsafevm);
  64 SYSCTL_INT(_debug, OID_AUTO, mpsafevm, CTLFLAG_RD, &debug_mpsafevm, 0,
  65     "Enable/disable MPSAFE virtual memory support");
  66
  67 struct vmmeter cnt;
  68
  69 int maxslp = MAXSLP;
  70
  71 SYSCTL_UINT(_vm, VM_V_FREE_MIN, v_free_min,
  72         CTLFLAG_RW, &cnt.v_free_min, 0, "");
  73 SYSCTL_UINT(_vm, VM_V_FREE_TARGET, v_free_target,
  74         CTLFLAG_RW, &cnt.v_free_target, 0, "");
  75 SYSCTL_UINT(_vm, VM_V_FREE_RESERVED, v_free_reserved,
  76         CTLFLAG_RW, &cnt.v_free_reserved, 0, "");
  77 SYSCTL_UINT(_vm, VM_V_INACTIVE_TARGET, v_inactive_target,
  78         CTLFLAG_RW, &cnt.v_inactive_target, 0, "");
  79 SYSCTL_UINT(_vm, VM_V_CACHE_MIN, v_cache_min,
  80         CTLFLAG_RW, &cnt.v_cache_min, 0, "");
  81 SYSCTL_UINT(_vm, VM_V_CACHE_MAX, v_cache_max,
  82         CTLFLAG_RW, &cnt.v_cache_max, 0, "");
  83 SYSCTL_UINT(_vm, VM_V_PAGEOUT_FREE_MIN, v_pageout_free_min,
  84         CTLFLAG_RW, &cnt.v_pageout_free_min, 0, "");
  85 SYSCTL_UINT(_vm, OID_AUTO, v_free_severe,
  86         CTLFLAG_RW, &cnt.v_free_severe, 0, "");
  87
  88 static int
  89 sysctl_vm_loadavg(SYSCTL_HANDLER_ARGS)
  90 {
  91 #ifdef SCTL_MASK32
  92         u_int32_t la[4];
  93
  94         if (req->flags & SCTL_MASK32) {
  95                 la[0] = averunnable.ldavg[0];
  96                 la[1] = averunnable.ldavg[1];
  97                 la[2] = averunnable.ldavg[2];
  98                 la[3] = averunnable.fscale;
  99                 return SYSCTL_OUT(req, la, sizeof(la));
 100         } else
 101 #endif
 102                 return SYSCTL_OUT(req, &averunnable, sizeof(averunnable));
 103 }
 104 SYSCTL_PROC(_vm, VM_LOADAVG, loadavg, CTLTYPE_STRUCT|CTLFLAG_RD,
 105     NULL, 0, sysctl_vm_loadavg, "S,loadavg", "Machine loadaverage history");
 106
 107 static int
 108 vmtotal(SYSCTL_HANDLER_ARGS)
 109 {
 110 /* XXXKSE almost completely broken */
 111         struct proc *p;
 112         struct vmtotal total;
 113         vm_map_entry_t entry;
 114         vm_object_t object;
 115         vm_map_t map;
 116         int paging;
 117         struct thread *td;
 118         struct vmspace *vm;
 119
 120         bzero(&total, sizeof(total));
 121         /*
 122          * Mark all objects as inactive.
 123          */
 124         GIANT_REQUIRED;
 125         mtx_lock(&vm_object_list_mtx);
 126         TAILQ_FOREACH(object, &vm_object_list, object_list) {
 127                 if (!VM_OBJECT_TRYLOCK(object)) {
 128                         /*
 129                          * Avoid a lock-order reversal.  Consequently,
 130                          * the reported number of active pages may be
 131                          * greater than the actual number.
 132                          */
 133                         continue;
 134                 }
 135                 vm_object_clear_flag(object, OBJ_ACTIVE);
 136                 VM_OBJECT_UNLOCK(object);
 137         }
 138         mtx_unlock(&vm_object_list_mtx);
 139         /*
 140          * Calculate process statistics.
 141          */
 142         sx_slock(&allproc_lock);
 143         FOREACH_PROC_IN_SYSTEM(p) {
 144                 if (p->p_flag & P_SYSTEM)
 145                         continue;
 146                 mtx_lock_spin(&sched_lock);
 147                 switch (p->p_state) {
 148                 case PRS_NEW:
 149                         mtx_unlock_spin(&sched_lock);
 150                         continue;
 151                         break;
 152                 default:
 153                         FOREACH_THREAD_IN_PROC(p, td) {
 154                                 /* Need new statistics  XXX */
 155                                 switch (td->td_state) {
 156                                 case TDS_INHIBITED:
 157                                         if (TD_ON_LOCK(td) ||
 158                                             (td->td_inhibitors ==
 159                                             TDI_SWAPPED)) {
 160                                                 total.t_sw++;
 161                                         } else if (TD_IS_SLEEPING(td) ||
 162                                            TD_AWAITING_INTR(td) ||
 163                                            TD_IS_SUSPENDED(td)) {
 164                                                 if (td->td_priority <= PZERO)
 165                                                         total.t_dw++;
 166                                                 else
 167                                                         total.t_sl++;
 168                                         }
 169                                         break;
 170
 171                                 case TDS_CAN_RUN:
 172                                         total.t_sw++;
 173                                         break;
 174                                 case TDS_RUNQ:
 175                                 case TDS_RUNNING:
 176                                         total.t_rq++;
 177                                         continue;
 178                                 default:
 179                                         break;
 180                                 }
 181                         }
 182                 }
 183                 mtx_unlock_spin(&sched_lock);
 184                 /*
 185                  * Note active objects.
 186                  */
 187                 paging = 0;
 188                 vm = vmspace_acquire_ref(p);
 189                 if (vm == NULL)
 190                         continue;
 191                 map = &vm->vm_map;
 192                 vm_map_lock_read(map);
 193                 for (entry = map->header.next;
 194                     entry != &map->header; entry = entry->next) {
 195                         if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) ||
 196                             (object = entry->object.vm_object) == NULL)
 197                                 continue;
 198                         VM_OBJECT_LOCK(object);
 199                         vm_object_set_flag(object, OBJ_ACTIVE);
 200                         paging |= object->paging_in_progress;
 201                         VM_OBJECT_UNLOCK(object);
 202                 }
 203                 vm_map_unlock_read(map);
 204                 vmspace_free(vm);
 205                 if (paging)
 206                         total.t_pw++;
 207         }
 208         sx_sunlock(&allproc_lock);
 209         /*
 210          * Calculate object memory usage statistics.
 211          */
 212         mtx_lock(&vm_object_list_mtx);
 213         TAILQ_FOREACH(object, &vm_object_list, object_list) {
 214                 /*
 215                  * Perform unsynchronized reads on the object to avoid
 216                  * a lock-order reversal.  In this case, the lack of
 217                  * synchronization should not impair the accuracy of
 218                  * the reported statistics.
 219                  */
 220                 if (object->type == OBJT_DEVICE) {
 221                         /*
 222                          * Devices, like /dev/mem, will badly skew our totals.
 223                          */
 224                         continue;
 225                 }
 226                 if (object->ref_count == 0) {
 227                         /*
 228                          * Also skip unreferenced objects, including
 229                          * vnodes representing mounted file systems.
 230                          */
 231                         continue;
 232                 }
 233                 total.t_vm += object->size;
 234                 total.t_rm += object->resident_page_count;
 235                 if (object->flags & OBJ_ACTIVE) {
 236                         total.t_avm += object->size;
 237                         total.t_arm += object->resident_page_count;
 238                 }
 239                 if (object->shadow_count > 1) {
 240                         /* shared object */
 241                         total.t_vmshr += object->size;
 242                         total.t_rmshr += object->resident_page_count;
 243                         if (object->flags & OBJ_ACTIVE) {
 244                                 total.t_avmshr += object->size;
 245                                 total.t_armshr += object->resident_page_count;
 246                         }
 247                 }
 248         }
 249         mtx_unlock(&vm_object_list_mtx);
 250         total.t_free = cnt.v_free_count + cnt.v_cache_count;
 251         return (sysctl_handle_opaque(oidp, &total, sizeof(total), req));
 252 }
 253
 254 /*
 255  * vcnt() -     accumulate statistics from all cpus and the global cnt
 256  *              structure.
 257  *
 258  *      The vmmeter structure is now per-cpu as well as global.  Those
 259  *      statistics which can be kept on a per-cpu basis (to avoid cache
 260  *      stalls between cpus) can be moved to the per-cpu vmmeter.  Remaining
 261  *      statistics, such as v_free_reserved, are left in the global
 262  *      structure.
 263  *
 264  * (sysctl_oid *oidp, void *arg1, int arg2, struct sysctl_req *req)
 265  */
 266 static int
 267 vcnt(SYSCTL_HANDLER_ARGS)
 268 {
 269         int count = *(int *)arg1;
 270         int offset = (char *)arg1 - (char *)&cnt;
 271 #ifdef SMP
 272         int i;
 273
 274         for (i = 0; i < mp_ncpus; ++i) {
 275                 struct pcpu *pcpu = pcpu_find(i);
 276                 count += *(int *)((char *)&pcpu->pc_cnt + offset);
 277         }
 278 #else
 279         count += *(int *)((char *)PCPU_PTR(cnt) + offset);
 280 #endif
 281         return (SYSCTL_OUT(req, &count, sizeof(int)));
 282 }
 283
 284 SYSCTL_PROC(_vm, VM_TOTAL, vmtotal, CTLTYPE_OPAQUE|CTLFLAG_RD,
 285     0, sizeof(struct vmtotal), vmtotal, "S,vmtotal",
 286     "System virtual memory statistics");
 287 SYSCTL_NODE(_vm, OID_AUTO, stats, CTLFLAG_RW, 0, "VM meter stats");
 288 static SYSCTL_NODE(_vm_stats, OID_AUTO, sys, CTLFLAG_RW, 0,
 289         "VM meter sys stats");
 290 static SYSCTL_NODE(_vm_stats, OID_AUTO, vm, CTLFLAG_RW, 0,
 291         "VM meter vm stats");
 292 SYSCTL_NODE(_vm_stats, OID_AUTO, misc, CTLFLAG_RW, 0, "VM meter misc stats");
 293
 294 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_swtch, CTLTYPE_UINT|CTLFLAG_RD,
 295         &cnt.v_swtch, 0, vcnt, "IU", "Context switches");
 296 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_trap, CTLTYPE_UINT|CTLFLAG_RD,
 297         &cnt.v_trap, 0, vcnt, "IU", "Traps");
 298 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_syscall, CTLTYPE_UINT|CTLFLAG_RD,
 299         &cnt.v_syscall, 0, vcnt, "IU", "Syscalls");
 300 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_intr, CTLTYPE_UINT|CTLFLAG_RD,
 301         &cnt.v_intr, 0, vcnt, "IU", "Hardware interrupts");
 302 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_soft, CTLTYPE_UINT|CTLFLAG_RD,
 303         &cnt.v_soft, 0, vcnt, "IU", "Software interrupts");
 304 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vm_faults, CTLTYPE_UINT|CTLFLAG_RD,
 305         &cnt.v_vm_faults, 0, vcnt, "IU", "VM faults");
 306 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cow_faults, CTLTYPE_UINT|CTLFLAG_RD,
 307         &cnt.v_cow_faults, 0, vcnt, "IU", "COW faults");
 308 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cow_optim, CTLTYPE_UINT|CTLFLAG_RD,
 309         &cnt.v_cow_optim, 0, vcnt, "IU", "Optimized COW faults");
 310 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_zfod, CTLTYPE_UINT|CTLFLAG_RD,
 311         &cnt.v_zfod, 0, vcnt, "IU", "Zero fill");
 312 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_ozfod, CTLTYPE_UINT|CTLFLAG_RD,
 313         &cnt.v_ozfod, 0, vcnt, "IU", "Optimized zero fill");
 314 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swapin, CTLTYPE_UINT|CTLFLAG_RD,
 315         &cnt.v_swapin, 0, vcnt, "IU", "Swapin operations");
 316 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swapout, CTLTYPE_UINT|CTLFLAG_RD,
 317         &cnt.v_swapout, 0, vcnt, "IU", "Swapout operations");
 318 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swappgsin, CTLTYPE_UINT|CTLFLAG_RD,
 319         &cnt.v_swappgsin, 0, vcnt, "IU", "Swapin pages");
 320 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swappgsout, CTLTYPE_UINT|CTLFLAG_RD,
 321         &cnt.v_swappgsout, 0, vcnt, "IU", "Swapout pages");
 322 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodein, CTLTYPE_UINT|CTLFLAG_RD,
 323         &cnt.v_vnodein, 0, vcnt, "IU", "Vnodein operations");
 324 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodeout, CTLTYPE_UINT|CTLFLAG_RD,
 325         &cnt.v_vnodeout, 0, vcnt, "IU", "Vnodeout operations");
 326 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodepgsin, CTLTYPE_UINT|CTLFLAG_RD,
 327         &cnt.v_vnodepgsin, 0, vcnt, "IU", "Vnodein pages");
 328 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodepgsout, CTLTYPE_UINT|CTLFLAG_RD,
 329         &cnt.v_vnodepgsout, 0, vcnt, "IU", "Vnodeout pages");
 330 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_intrans, CTLTYPE_UINT|CTLFLAG_RD,
 331         &cnt.v_intrans, 0, vcnt, "IU", "In transit page blocking");
 332 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_reactivated, CTLTYPE_UINT|CTLFLAG_RD,
 333         &cnt.v_reactivated, 0, vcnt, "IU", "Reactivated pages");
 334 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pdwakeups, CTLTYPE_UINT|CTLFLAG_RD,
 335         &cnt.v_pdwakeups, 0, vcnt, "IU", "Pagedaemon wakeups");
 336 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pdpages, CTLTYPE_UINT|CTLFLAG_RD,
 337         &cnt.v_pdpages, 0, vcnt, "IU", "Pagedaemon page scans");
 338 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_dfree, CTLTYPE_UINT|CTLFLAG_RD,
 339         &cnt.v_dfree, 0, vcnt, "IU", "");
 340 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pfree, CTLTYPE_UINT|CTLFLAG_RD,
 341         &cnt.v_pfree, 0, vcnt, "IU", "");
 342 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_tfree, CTLTYPE_UINT|CTLFLAG_RD,
 343         &cnt.v_tfree, 0, vcnt, "IU", "");
 344 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_page_size, CTLTYPE_UINT|CTLFLAG_RD,
 345         &cnt.v_page_size, 0, vcnt, "IU", "");
 346 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_page_count, CTLTYPE_UINT|CTLFLAG_RD,
 347         &cnt.v_page_count, 0, vcnt, "IU", "");
 348 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_reserved, CTLTYPE_UINT|CTLFLAG_RD,
 349         &cnt.v_free_reserved, 0, vcnt, "IU", "");
 350 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_target, CTLTYPE_UINT|CTLFLAG_RD,
 351         &cnt.v_free_target, 0, vcnt, "IU", "");
 352 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_min, CTLTYPE_UINT|CTLFLAG_RD,
 353         &cnt.v_free_min, 0, vcnt, "IU", "");
 354 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_count, CTLTYPE_UINT|CTLFLAG_RD,
 355         &cnt.v_free_count, 0, vcnt, "IU", "");
 356 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_wire_count, CTLTYPE_UINT|CTLFLAG_RD,
 357         &cnt.v_wire_count, 0, vcnt, "IU", "");
 358 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_active_count, CTLTYPE_UINT|CTLFLAG_RD,
 359         &cnt.v_active_count, 0, vcnt, "IU", "");
 360 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_inactive_target, CTLTYPE_UINT|CTLFLAG_RD,
 361         &cnt.v_inactive_target, 0, vcnt, "IU", "");
 362 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_inactive_count, CTLTYPE_UINT|CTLFLAG_RD,
 363         &cnt.v_inactive_count, 0, vcnt, "IU", "");
 364 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cache_count, CTLTYPE_UINT|CTLFLAG_RD,
 365         &cnt.v_cache_count, 0, vcnt, "IU", "");
 366 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cache_min, CTLTYPE_UINT|CTLFLAG_RD,
 367         &cnt.v_cache_min, 0, vcnt, "IU", "");
 368 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cache_max, CTLTYPE_UINT|CTLFLAG_RD,
 369         &cnt.v_cache_max, 0, vcnt, "IU", "");
 370 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pageout_free_min, CTLTYPE_UINT|CTLFLAG_RD,
 371         &cnt.v_pageout_free_min, 0, vcnt, "IU", "");
 372 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_interrupt_free_min, CTLTYPE_UINT|CTLFLAG_RD,
 373         &cnt.v_interrupt_free_min, 0, vcnt, "IU", "");
 374 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_forks, CTLTYPE_UINT|CTLFLAG_RD,
 375         &cnt.v_forks, 0, vcnt, "IU", "Number of fork() calls");
 376 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vforks, CTLTYPE_UINT|CTLFLAG_RD,
 377         &cnt.v_vforks, 0, vcnt, "IU", "Number of vfork() calls");
 378 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_rforks, CTLTYPE_UINT|CTLFLAG_RD,
 379         &cnt.v_rforks, 0, vcnt, "IU", "Number of rfork() calls");
 380 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_kthreads, CTLTYPE_UINT|CTLFLAG_RD,
 381         &cnt.v_kthreads, 0, vcnt, "IU", "Number of fork() calls by kernel");
 382 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_forkpages, CTLTYPE_UINT|CTLFLAG_RD,
 383         &cnt.v_forkpages, 0, vcnt, "IU", "VM pages affected by fork()");
 384 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vforkpages, CTLTYPE_UINT|CTLFLAG_RD,
 385         &cnt.v_vforkpages, 0, vcnt, "IU", "VM pages affected by vfork()");
 386 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_rforkpages, CTLTYPE_UINT|CTLFLAG_RD,
 387         &cnt.v_rforkpages, 0, vcnt, "IU", "VM pages affected by rfork()");
 388 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_kthreadpages, CTLTYPE_UINT|CTLFLAG_RD,
 389         &cnt.v_kthreadpages, 0, vcnt, "IU", "VM pages affected by fork() by kernel");
 390
 391 SYSCTL_INT(_vm_stats_misc, OID_AUTO,
 392         zero_page_count, CTLFLAG_RD, &vm_page_zero_count, 0, "");
 393 #if 0
 394 SYSCTL_INT(_vm_stats_misc, OID_AUTO,
 395         page_mask, CTLFLAG_RD, &page_mask, 0, "");
 396 SYSCTL_INT(_vm_stats_misc, OID_AUTO,
 397         page_shift, CTLFLAG_RD, &page_shift, 0, "");
 398 SYSCTL_INT(_vm_stats_misc, OID_AUTO,
 399         first_page, CTLFLAG_RD, &first_page, 0, "");
 400 SYSCTL_INT(_vm_stats_misc, OID_AUTO,
 401         last_page, CTLFLAG_RD, &last_page, 0, "");
 402 #endif