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  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  *      @(#)vm_meter.c  8.4 (Berkeley) 1/4/94
  34  * $FreeBSD: src/sys/vm/vm_meter.c,v 1.34.2.7 2002/10/10 19:28:22 dillon Exp $
  35  * $DragonFly: src/sys/vm/vm_meter.c,v 1.14 2007/02/19 01:14:24 corecode Exp $
  36  */
  37
  38 #include <sys/param.h>
  39 #include <sys/proc.h>
  40 #include <sys/systm.h>
  41 #include <sys/kernel.h>
  42 #include <sys/resource.h>
  43 #include <sys/vmmeter.h>
  44
  45 #include <vm/vm.h>
  46 #include <vm/vm_page.h>
  47 #include <vm/vm_extern.h>
  48 #include <vm/vm_param.h>
  49 #include <sys/lock.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 vmstats vmstats;
  56
  57 static int maxslp = MAXSLP;
  58
  59 SYSCTL_UINT(_vm, VM_V_FREE_MIN, v_free_min,
  60         CTLFLAG_RW, &vmstats.v_free_min, 0, "");
  61 SYSCTL_UINT(_vm, VM_V_FREE_TARGET, v_free_target,
  62         CTLFLAG_RW, &vmstats.v_free_target, 0, "");
  63 SYSCTL_UINT(_vm, VM_V_FREE_RESERVED, v_free_reserved,
  64         CTLFLAG_RW, &vmstats.v_free_reserved, 0, "");
  65 SYSCTL_UINT(_vm, VM_V_INACTIVE_TARGET, v_inactive_target,
  66         CTLFLAG_RW, &vmstats.v_inactive_target, 0, "");
  67 SYSCTL_UINT(_vm, VM_V_CACHE_MIN, v_cache_min,
  68         CTLFLAG_RW, &vmstats.v_cache_min, 0, "");
  69 SYSCTL_UINT(_vm, VM_V_CACHE_MAX, v_cache_max,
  70         CTLFLAG_RW, &vmstats.v_cache_max, 0, "");
  71 SYSCTL_UINT(_vm, VM_V_PAGEOUT_FREE_MIN, v_pageout_free_min,
  72         CTLFLAG_RW, &vmstats.v_pageout_free_min, 0, "");
  73 SYSCTL_UINT(_vm, OID_AUTO, v_free_severe,
  74         CTLFLAG_RW, &vmstats.v_free_severe, 0, "");
  75
  76 SYSCTL_STRUCT(_vm, VM_LOADAVG, loadavg, CTLFLAG_RD,
  77     &averunnable, loadavg, "Machine loadaverage history");
  78
  79 static int do_vmtotal_callback(struct proc *p, void *data);
  80
  81 static int
  82 do_vmtotal(SYSCTL_HANDLER_ARGS)
  83 {
  84         struct vmtotal total;
  85         struct vmtotal *totalp;
  86         vm_object_t object;
  87
  88         totalp = &total;
  89         bzero(totalp, sizeof *totalp);
  90
  91         /*
  92          * Mark all objects as inactive.
  93          */
  94         for (object = TAILQ_FIRST(&vm_object_list);
  95             object != NULL;
  96             object = TAILQ_NEXT(object,object_list)) {
  97                 vm_object_clear_flag(object, OBJ_ACTIVE);
  98         }
  99
 100         /*
 101          * Calculate process statistics.
 102          */
 103         allproc_scan(do_vmtotal_callback, totalp);
 104
 105         /*
 106          * Calculate object memory usage statistics.
 107          */
 108         for (object = TAILQ_FIRST(&vm_object_list);
 109             object != NULL;
 110             object = TAILQ_NEXT(object, object_list)) {
 111                 /*
 112                  * devices, like /dev/mem, will badly skew our totals
 113                  */
 114                 if (object->type == OBJT_DEVICE)
 115                         continue;
 116                 totalp->t_vm += object->size;
 117                 totalp->t_rm += object->resident_page_count;
 118                 if (object->flags & OBJ_ACTIVE) {
 119                         totalp->t_avm += object->size;
 120                         totalp->t_arm += object->resident_page_count;
 121                 }
 122                 if (object->shadow_count > 1) {
 123                         /* shared object */
 124                         totalp->t_vmshr += object->size;
 125                         totalp->t_rmshr += object->resident_page_count;
 126                         if (object->flags & OBJ_ACTIVE) {
 127                                 totalp->t_avmshr += object->size;
 128                                 totalp->t_armshr += object->resident_page_count;
 129                         }
 130                 }
 131         }
 132         totalp->t_free = vmstats.v_free_count + vmstats.v_cache_count;
 133         return (sysctl_handle_opaque(oidp, totalp, sizeof total, req));
 134 }
 135
 136 static int
 137 do_vmtotal_callback(struct proc *p, void *data)
 138 {
 139         struct vmtotal *totalp = data;
 140         struct lwp *lp;
 141         vm_map_entry_t entry;
 142         vm_map_t map;
 143         int paging;
 144
 145         if (p->p_flag & P_SYSTEM)
 146                 return(0);
 147
 148         FOREACH_LWP_IN_PROC(lp, p) {
 149                 switch (lp->lwp_stat) {
 150                 case LSSTOP:
 151                 case LSSLEEP:
 152                         if ((p->p_flag & P_SWAPPEDOUT) == 0) {
 153                                 if ((lp->lwp_flag & LWP_SINTR) == 0)
 154                                         totalp->t_dw++;
 155                                 else if (lp->lwp_slptime < maxslp)
 156                                         totalp->t_sl++;
 157                         } else if (lp->lwp_slptime < maxslp) {
 158                                 totalp->t_sw++;
 159                         }
 160                         if (lp->lwp_slptime >= maxslp)
 161                                 return(0);
 162                         break;
 163
 164                 case LSRUN:
 165                         if (p->p_flag & P_SWAPPEDOUT)
 166                                 totalp->t_sw++;
 167                         else
 168                                 totalp->t_rq++;
 169                         if (p->p_stat == SIDL)
 170                                 return(0);
 171                         break;
 172
 173                 default:
 174                         return (0);
 175                 }
 176         }
 177         /*
 178          * Note active objects.
 179          */
 180         paging = 0;
 181         for (map = &p->p_vmspace->vm_map, entry = map->header.next;
 182             entry != &map->header; entry = entry->next) {
 183                 if (entry->maptype != VM_MAPTYPE_NORMAL &&
 184                     entry->maptype != VM_MAPTYPE_VPAGETABLE) {
 185                         continue;
 186                 }
 187                 if (entry->object.vm_object == NULL)
 188                         continue;
 189                 vm_object_set_flag(entry->object.vm_object, OBJ_ACTIVE);
 190                 paging |= entry->object.vm_object->paging_in_progress;
 191         }
 192         if (paging)
 193                 totalp->t_pw++;
 194         return(0);
 195 }
 196
 197
 198 static int
 199 do_vmstats(SYSCTL_HANDLER_ARGS)
 200 {
 201         struct vmstats vms = vmstats;
 202         return (sysctl_handle_opaque(oidp, &vms, sizeof(vms), req));
 203 }
 204
 205 static int
 206 do_vmmeter(SYSCTL_HANDLER_ARGS)
 207 {
 208         int boffset = offsetof(struct vmmeter, vmmeter_uint_begin);
 209         int eoffset = offsetof(struct vmmeter, vmmeter_uint_end);
 210         struct vmmeter vmm;
 211         int i;
 212
 213         bzero(&vmm, sizeof(vmm));
 214         for (i = 0; i < ncpus; ++i) {
 215                 int off;
 216                 struct globaldata *gd = globaldata_find(i);
 217
 218                 for (off = boffset; off <= eoffset; off += sizeof(u_int)) {
 219                         *(u_int *)((char *)&vmm + off) +=
 220                                 *(u_int *)((char *)&gd->gd_cnt + off);
 221                 }
 222
 223         }
 224         return (sysctl_handle_opaque(oidp, &vmm, sizeof(vmm), req));
 225 }
 226
 227 /*
 228  * vcnt() -     accumulate statistics from the cnt structure for each cpu
 229  *
 230  *      The vmmeter structure is now per-cpu as well as global.  Those
 231  *      statistics which can be kept on a per-cpu basis (to avoid cache
 232  *      stalls between cpus) can be moved to the per-cpu vmmeter.  Remaining
 233  *      statistics, such as v_free_reserved, are left in the global
 234  *      structure.
 235  *
 236  * (sysctl_oid *oidp, void *arg1, int arg2, struct sysctl_req *req)
 237  */
 238 static int
 239 vcnt(SYSCTL_HANDLER_ARGS)
 240 {
 241         int i;
 242         int count = 0;
 243         int offset = arg2;
 244
 245         for (i = 0; i < ncpus; ++i) {
 246                 struct globaldata *gd = globaldata_find(i);
 247                 count += *(int *)((char *)&gd->gd_cnt + offset);
 248         }
 249         return(SYSCTL_OUT(req, &count, sizeof(int)));
 250 }
 251
 252 #define VMMETEROFF(var) offsetof(struct vmmeter, var)
 253
 254 SYSCTL_PROC(_vm, OID_AUTO, vmtotal, CTLTYPE_OPAQUE|CTLFLAG_RD,
 255     0, sizeof(struct vmtotal), do_vmtotal, "S,vmtotal",
 256     "System virtual memory aggregate");
 257 SYSCTL_PROC(_vm, OID_AUTO, vmstats, CTLTYPE_OPAQUE|CTLFLAG_RD,
 258     0, sizeof(struct vmstats), do_vmstats, "S,vmstats",
 259     "System virtual memory statistics");
 260 SYSCTL_PROC(_vm, OID_AUTO, vmmeter, CTLTYPE_OPAQUE|CTLFLAG_RD,
 261     0, sizeof(struct vmmeter), do_vmmeter, "S,vmmeter",
 262     "System per-cpu statistics");
 263 SYSCTL_NODE(_vm, OID_AUTO, stats, CTLFLAG_RW, 0, "VM meter stats");
 264 SYSCTL_NODE(_vm_stats, OID_AUTO, sys, CTLFLAG_RW, 0, "VM meter sys stats");
 265 SYSCTL_NODE(_vm_stats, OID_AUTO, vm, CTLFLAG_RW, 0, "VM meter vm stats");
 266 SYSCTL_NODE(_vm_stats, OID_AUTO, misc, CTLFLAG_RW, 0, "VM meter misc stats");
 267
 268 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_swtch, CTLTYPE_UINT|CTLFLAG_RD,
 269         0, VMMETEROFF(v_swtch), vcnt, "IU", "Context switches");
 270 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_intrans_coll, CTLTYPE_UINT|CTLFLAG_RD,
 271         0, VMMETEROFF(v_intrans_coll), vcnt, "IU", "");
 272 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_intrans_wait, CTLTYPE_UINT|CTLFLAG_RD,
 273         0, VMMETEROFF(v_intrans_wait), vcnt, "IU", "");
 274 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_forwarded_ints, CTLTYPE_UINT|CTLFLAG_RD,
 275         0, VMMETEROFF(v_forwarded_ints), vcnt, "IU", "");
 276 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_forwarded_hits, CTLTYPE_UINT|CTLFLAG_RD,
 277         0, VMMETEROFF(v_forwarded_hits), vcnt, "IU", "");
 278 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_forwarded_misses, CTLTYPE_UINT|CTLFLAG_RD,
 279         0, VMMETEROFF(v_forwarded_misses), vcnt, "IU", "");
 280 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_trap, CTLTYPE_UINT|CTLFLAG_RD,
 281         0, VMMETEROFF(v_trap), vcnt, "IU", "Traps");
 282 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_syscall, CTLTYPE_UINT|CTLFLAG_RD,
 283         0, VMMETEROFF(v_syscall), vcnt, "IU", "Syscalls");
 284 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_intr, CTLTYPE_UINT|CTLFLAG_RD,
 285         0, VMMETEROFF(v_intr), vcnt, "IU", "Hardware interrupts");
 286 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_soft, CTLTYPE_UINT|CTLFLAG_RD,
 287         0, VMMETEROFF(v_soft), vcnt, "IU", "Software interrupts");
 288 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vm_faults, CTLTYPE_UINT|CTLFLAG_RD,
 289         0, VMMETEROFF(v_vm_faults), vcnt, "IU", "VM faults");
 290 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cow_faults, CTLTYPE_UINT|CTLFLAG_RD,
 291         0, VMMETEROFF(v_cow_faults), vcnt, "IU", "COW faults");
 292 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cow_optim, CTLTYPE_UINT|CTLFLAG_RD,
 293         0, VMMETEROFF(v_cow_optim), vcnt, "IU", "Optimized COW faults");
 294 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_zfod, CTLTYPE_UINT|CTLFLAG_RD,
 295         0, VMMETEROFF(v_zfod), vcnt, "IU", "Zero fill");
 296 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_ozfod, CTLTYPE_UINT|CTLFLAG_RD,
 297         0, VMMETEROFF(v_ozfod), vcnt, "IU", "Optimized zero fill");
 298 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swapin, CTLTYPE_UINT|CTLFLAG_RD,
 299         0, VMMETEROFF(v_swapin), vcnt, "IU", "Swapin operations");
 300 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swapout, CTLTYPE_UINT|CTLFLAG_RD,
 301         0, VMMETEROFF(v_swapout), vcnt, "IU", "Swapout operations");
 302 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swappgsin, CTLTYPE_UINT|CTLFLAG_RD,
 303         0, VMMETEROFF(v_swappgsin), vcnt, "IU", "Swapin pages");
 304 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swappgsout, CTLTYPE_UINT|CTLFLAG_RD,
 305         0, VMMETEROFF(v_swappgsout), vcnt, "IU", "Swapout pages");
 306 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodein, CTLTYPE_UINT|CTLFLAG_RD,
 307         0, VMMETEROFF(v_vnodein), vcnt, "IU", "Vnodein operations");
 308 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodeout, CTLTYPE_UINT|CTLFLAG_RD,
 309         0, VMMETEROFF(v_vnodeout), vcnt, "IU", "Vnodeout operations");
 310 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodepgsin, CTLTYPE_UINT|CTLFLAG_RD,
 311         0, VMMETEROFF(v_vnodepgsin), vcnt, "IU", "Vnodein pages");
 312 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodepgsout, CTLTYPE_UINT|CTLFLAG_RD,
 313         0, VMMETEROFF(v_vnodepgsout), vcnt, "IU", "Vnodeout pages");
 314 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_intrans, CTLTYPE_UINT|CTLFLAG_RD,
 315         0, VMMETEROFF(v_intrans), vcnt, "IU", "In transit page blocking");
 316 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_reactivated, CTLTYPE_UINT|CTLFLAG_RD,
 317         0, VMMETEROFF(v_reactivated), vcnt, "IU", "Reactivated pages");
 318 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pdwakeups, CTLTYPE_UINT|CTLFLAG_RD,
 319         0, VMMETEROFF(v_pdwakeups), vcnt, "IU", "Pagedaemon wakeups");
 320 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pdpages, CTLTYPE_UINT|CTLFLAG_RD,
 321         0, VMMETEROFF(v_pdpages), vcnt, "IU", "Pagedaemon page scans");
 322 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_dfree, CTLTYPE_UINT|CTLFLAG_RD,
 323         0, VMMETEROFF(v_dfree), vcnt, "IU", "");
 324 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pfree, CTLTYPE_UINT|CTLFLAG_RD,
 325         0, VMMETEROFF(v_pfree), vcnt, "IU", "");
 326 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_tfree, CTLTYPE_UINT|CTLFLAG_RD,
 327         0, VMMETEROFF(v_tfree), vcnt, "IU", "");
 328 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_forks, CTLTYPE_UINT|CTLFLAG_RD,
 329         0, VMMETEROFF(v_forks), vcnt, "IU", "Number of fork() calls");
 330 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vforks, CTLTYPE_UINT|CTLFLAG_RD,
 331         0, VMMETEROFF(v_vforks), vcnt, "IU", "Number of vfork() calls");
 332 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_rforks, CTLTYPE_UINT|CTLFLAG_RD,
 333         0, VMMETEROFF(v_rforks), vcnt, "IU", "Number of rfork() calls");
 334 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_kthreads, CTLTYPE_UINT|CTLFLAG_RD,
 335         0, VMMETEROFF(v_kthreads), vcnt, "IU", "Number of fork() calls by kernel");
 336 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_forkpages, CTLTYPE_UINT|CTLFLAG_RD,
 337         0, VMMETEROFF(v_forkpages), vcnt, "IU", "VM pages affected by fork()");
 338 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vforkpages, CTLTYPE_UINT|CTLFLAG_RD,
 339         0, VMMETEROFF(v_vforkpages), vcnt, "IU", "VM pages affected by vfork()");
 340 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_rforkpages, CTLTYPE_UINT|CTLFLAG_RD,
 341         0, VMMETEROFF(v_rforkpages), vcnt, "IU", "VM pages affected by rfork()");
 342 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_kthreadpages, CTLTYPE_UINT|CTLFLAG_RD,
 343         0, VMMETEROFF(v_kthreadpages), vcnt, "IU", "VM pages affected by fork() by kernel");
 344
 345 SYSCTL_UINT(_vm_stats_vm, OID_AUTO,
 346         v_page_size, CTLFLAG_RD, &vmstats.v_page_size, 0, "");
 347 SYSCTL_UINT(_vm_stats_vm, OID_AUTO,
 348         v_page_count, CTLFLAG_RD, &vmstats.v_page_count, 0, "");
 349 SYSCTL_UINT(_vm_stats_vm, OID_AUTO,
 350         v_free_reserved, CTLFLAG_RD, &vmstats.v_free_reserved, 0, "");
 351 SYSCTL_UINT(_vm_stats_vm, OID_AUTO,
 352         v_free_target, CTLFLAG_RD, &vmstats.v_free_target, 0, "");
 353 SYSCTL_UINT(_vm_stats_vm, OID_AUTO,
 354         v_free_min, CTLFLAG_RD, &vmstats.v_free_min, 0, "");
 355 SYSCTL_UINT(_vm_stats_vm, OID_AUTO,
 356         v_free_count, CTLFLAG_RD, &vmstats.v_free_count, 0, "");
 357 SYSCTL_UINT(_vm_stats_vm, OID_AUTO,
 358         v_wire_count, CTLFLAG_RD, &vmstats.v_wire_count, 0, "");
 359 SYSCTL_UINT(_vm_stats_vm, OID_AUTO,
 360         v_active_count, CTLFLAG_RD, &vmstats.v_active_count, 0, "");
 361 SYSCTL_UINT(_vm_stats_vm, OID_AUTO,
 362         v_inactive_target, CTLFLAG_RD, &vmstats.v_inactive_target, 0, "");
 363 SYSCTL_UINT(_vm_stats_vm, OID_AUTO,
 364         v_inactive_count, CTLFLAG_RD, &vmstats.v_inactive_count, 0, "");
 365 SYSCTL_UINT(_vm_stats_vm, OID_AUTO,
 366         v_cache_count, CTLFLAG_RD, &vmstats.v_cache_count, 0, "");
 367 SYSCTL_UINT(_vm_stats_vm, OID_AUTO,
 368         v_cache_min, CTLFLAG_RD, &vmstats.v_cache_min, 0, "");
 369 SYSCTL_UINT(_vm_stats_vm, OID_AUTO,
 370         v_cache_max, CTLFLAG_RD, &vmstats.v_cache_max, 0, "");
 371 SYSCTL_UINT(_vm_stats_vm, OID_AUTO,
 372         v_pageout_free_min, CTLFLAG_RD, &vmstats.v_pageout_free_min, 0, "");
 373 SYSCTL_UINT(_vm_stats_vm, OID_AUTO,
 374         v_interrupt_free_min, CTLFLAG_RD, &vmstats.v_interrupt_free_min, 0, "");
 375 SYSCTL_INT(_vm_stats_misc, OID_AUTO,
 376         zero_page_count, CTLFLAG_RD, &vm_page_zero_count, 0, "");