xref: /freebsd/sys/vm/vm_meter.c (revision a743df5c964d81a7c920cf257e87cb42ab993d58)
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, *totalp;
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 	totalp = &total;
121 	bzero(totalp, sizeof *totalp);
122 	/*
123 	 * Mark all objects as inactive.
124 	 */
125 	GIANT_REQUIRED;
126 	mtx_lock(&vm_object_list_mtx);
127 	TAILQ_FOREACH(object, &vm_object_list, object_list) {
128 		if (!VM_OBJECT_TRYLOCK(object)) {
129 			/*
130 			 * Avoid a lock-order reversal.  Consequently,
131 			 * the reported number of active pages may be
132 			 * greater than the actual number.
133 			 */
134 			continue;
135 		}
136 		vm_object_clear_flag(object, OBJ_ACTIVE);
137 		VM_OBJECT_UNLOCK(object);
138 	}
139 	mtx_unlock(&vm_object_list_mtx);
140 	/*
141 	 * Calculate process statistics.
142 	 */
143 	sx_slock(&allproc_lock);
144 	FOREACH_PROC_IN_SYSTEM(p) {
145 		if (p->p_flag & P_SYSTEM)
146 			continue;
147 		mtx_lock_spin(&sched_lock);
148 		switch (p->p_state) {
149 		case PRS_NEW:
150 			mtx_unlock_spin(&sched_lock);
151 			continue;
152 			break;
153 		default:
154 			FOREACH_THREAD_IN_PROC(p, td) {
155 				/* Need new statistics  XXX */
156 				switch (td->td_state) {
157 				case TDS_INHIBITED:
158 					if (TD_ON_LOCK(td) ||
159 					    (td->td_inhibitors ==
160 					    TDI_SWAPPED)) {
161 						totalp->t_sw++;
162 					} else if (TD_IS_SLEEPING(td) ||
163 					   TD_AWAITING_INTR(td) ||
164 					   TD_IS_SUSPENDED(td)) {
165 						if (td->td_priority <= PZERO)
166 							totalp->t_dw++;
167 						else
168 							totalp->t_sl++;
169 					}
170 					break;
171 
172 				case TDS_CAN_RUN:
173 					totalp->t_sw++;
174 					break;
175 				case TDS_RUNQ:
176 				case TDS_RUNNING:
177 					totalp->t_rq++;
178 					continue;
179 				default:
180 					break;
181 				}
182 			}
183 		}
184 		mtx_unlock_spin(&sched_lock);
185 		/*
186 		 * Note active objects.
187 		 */
188 		paging = 0;
189 		vm = vmspace_acquire_ref(p);
190 		if (vm == NULL)
191 			continue;
192 		map = &vm->vm_map;
193 		vm_map_lock_read(map);
194 		for (entry = map->header.next;
195 		    entry != &map->header; entry = entry->next) {
196 			if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) ||
197 			    (object = entry->object.vm_object) == NULL)
198 				continue;
199 			VM_OBJECT_LOCK(object);
200 			vm_object_set_flag(object, OBJ_ACTIVE);
201 			paging |= object->paging_in_progress;
202 			VM_OBJECT_UNLOCK(object);
203 		}
204 		vm_map_unlock_read(map);
205 		vmspace_free(vm);
206 		if (paging)
207 			totalp->t_pw++;
208 	}
209 	sx_sunlock(&allproc_lock);
210 	/*
211 	 * Calculate object memory usage statistics.
212 	 */
213 	mtx_lock(&vm_object_list_mtx);
214 	TAILQ_FOREACH(object, &vm_object_list, object_list) {
215 		/*
216 		 * Perform unsynchronized reads on the object to avoid
217 		 * a lock-order reversal.  In this case, the lack of
218 		 * synchronization should not impair the accuracy of
219 		 * the reported statistics.
220 		 */
221 		if (object->type == OBJT_DEVICE) {
222 			/*
223 			 * Devices, like /dev/mem, will badly skew our totals.
224 			 */
225 			continue;
226 		}
227 		totalp->t_vm += object->size;
228 		totalp->t_rm += object->resident_page_count;
229 		if (object->flags & OBJ_ACTIVE) {
230 			totalp->t_avm += object->size;
231 			totalp->t_arm += object->resident_page_count;
232 		}
233 		if (object->shadow_count > 1) {
234 			/* shared object */
235 			totalp->t_vmshr += object->size;
236 			totalp->t_rmshr += object->resident_page_count;
237 			if (object->flags & OBJ_ACTIVE) {
238 				totalp->t_avmshr += object->size;
239 				totalp->t_armshr += object->resident_page_count;
240 			}
241 		}
242 	}
243 	mtx_unlock(&vm_object_list_mtx);
244 	totalp->t_free = cnt.v_free_count + cnt.v_cache_count;
245 	return (sysctl_handle_opaque(oidp, totalp, sizeof total, req));
246 }
247 
248 /*
249  * vcnt() -	accumulate statistics from all cpus and the global cnt
250  *		structure.
251  *
252  *	The vmmeter structure is now per-cpu as well as global.  Those
253  *	statistics which can be kept on a per-cpu basis (to avoid cache
254  *	stalls between cpus) can be moved to the per-cpu vmmeter.  Remaining
255  *	statistics, such as v_free_reserved, are left in the global
256  *	structure.
257  *
258  * (sysctl_oid *oidp, void *arg1, int arg2, struct sysctl_req *req)
259  */
260 static int
261 vcnt(SYSCTL_HANDLER_ARGS)
262 {
263 	int count = *(int *)arg1;
264 	int offset = (char *)arg1 - (char *)&cnt;
265 #ifdef SMP
266 	int i;
267 
268 	for (i = 0; i < mp_ncpus; ++i) {
269 		struct pcpu *pcpu = pcpu_find(i);
270 		count += *(int *)((char *)&pcpu->pc_cnt + offset);
271 	}
272 #else
273 	count += *(int *)((char *)PCPU_PTR(cnt) + offset);
274 #endif
275 	return (SYSCTL_OUT(req, &count, sizeof(int)));
276 }
277 
278 SYSCTL_PROC(_vm, VM_TOTAL, vmtotal, CTLTYPE_OPAQUE|CTLFLAG_RD,
279     0, sizeof(struct vmtotal), vmtotal, "S,vmtotal",
280     "System virtual memory statistics");
281 SYSCTL_NODE(_vm, OID_AUTO, stats, CTLFLAG_RW, 0, "VM meter stats");
282 static SYSCTL_NODE(_vm_stats, OID_AUTO, sys, CTLFLAG_RW, 0,
283 	"VM meter sys stats");
284 static SYSCTL_NODE(_vm_stats, OID_AUTO, vm, CTLFLAG_RW, 0,
285 	"VM meter vm stats");
286 SYSCTL_NODE(_vm_stats, OID_AUTO, misc, CTLFLAG_RW, 0, "VM meter misc stats");
287 
288 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_swtch, CTLTYPE_UINT|CTLFLAG_RD,
289 	&cnt.v_swtch, 0, vcnt, "IU", "Context switches");
290 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_trap, CTLTYPE_UINT|CTLFLAG_RD,
291 	&cnt.v_trap, 0, vcnt, "IU", "Traps");
292 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_syscall, CTLTYPE_UINT|CTLFLAG_RD,
293 	&cnt.v_syscall, 0, vcnt, "IU", "Syscalls");
294 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_intr, CTLTYPE_UINT|CTLFLAG_RD,
295 	&cnt.v_intr, 0, vcnt, "IU", "Hardware interrupts");
296 SYSCTL_PROC(_vm_stats_sys, OID_AUTO, v_soft, CTLTYPE_UINT|CTLFLAG_RD,
297 	&cnt.v_soft, 0, vcnt, "IU", "Software interrupts");
298 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vm_faults, CTLTYPE_UINT|CTLFLAG_RD,
299 	&cnt.v_vm_faults, 0, vcnt, "IU", "VM faults");
300 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cow_faults, CTLTYPE_UINT|CTLFLAG_RD,
301 	&cnt.v_cow_faults, 0, vcnt, "IU", "COW faults");
302 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cow_optim, CTLTYPE_UINT|CTLFLAG_RD,
303 	&cnt.v_cow_optim, 0, vcnt, "IU", "Optimized COW faults");
304 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_zfod, CTLTYPE_UINT|CTLFLAG_RD,
305 	&cnt.v_zfod, 0, vcnt, "IU", "Zero fill");
306 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_ozfod, CTLTYPE_UINT|CTLFLAG_RD,
307 	&cnt.v_ozfod, 0, vcnt, "IU", "Optimized zero fill");
308 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swapin, CTLTYPE_UINT|CTLFLAG_RD,
309 	&cnt.v_swapin, 0, vcnt, "IU", "Swapin operations");
310 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swapout, CTLTYPE_UINT|CTLFLAG_RD,
311 	&cnt.v_swapout, 0, vcnt, "IU", "Swapout operations");
312 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swappgsin, CTLTYPE_UINT|CTLFLAG_RD,
313 	&cnt.v_swappgsin, 0, vcnt, "IU", "Swapin pages");
314 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_swappgsout, CTLTYPE_UINT|CTLFLAG_RD,
315 	&cnt.v_swappgsout, 0, vcnt, "IU", "Swapout pages");
316 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodein, CTLTYPE_UINT|CTLFLAG_RD,
317 	&cnt.v_vnodein, 0, vcnt, "IU", "Vnodein operations");
318 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodeout, CTLTYPE_UINT|CTLFLAG_RD,
319 	&cnt.v_vnodeout, 0, vcnt, "IU", "Vnodeout operations");
320 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodepgsin, CTLTYPE_UINT|CTLFLAG_RD,
321 	&cnt.v_vnodepgsin, 0, vcnt, "IU", "Vnodein pages");
322 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vnodepgsout, CTLTYPE_UINT|CTLFLAG_RD,
323 	&cnt.v_vnodepgsout, 0, vcnt, "IU", "Vnodeout pages");
324 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_intrans, CTLTYPE_UINT|CTLFLAG_RD,
325 	&cnt.v_intrans, 0, vcnt, "IU", "In transit page blocking");
326 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_reactivated, CTLTYPE_UINT|CTLFLAG_RD,
327 	&cnt.v_reactivated, 0, vcnt, "IU", "Reactivated pages");
328 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pdwakeups, CTLTYPE_UINT|CTLFLAG_RD,
329 	&cnt.v_pdwakeups, 0, vcnt, "IU", "Pagedaemon wakeups");
330 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pdpages, CTLTYPE_UINT|CTLFLAG_RD,
331 	&cnt.v_pdpages, 0, vcnt, "IU", "Pagedaemon page scans");
332 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_dfree, CTLTYPE_UINT|CTLFLAG_RD,
333 	&cnt.v_dfree, 0, vcnt, "IU", "");
334 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pfree, CTLTYPE_UINT|CTLFLAG_RD,
335 	&cnt.v_pfree, 0, vcnt, "IU", "");
336 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_tfree, CTLTYPE_UINT|CTLFLAG_RD,
337 	&cnt.v_tfree, 0, vcnt, "IU", "");
338 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_page_size, CTLTYPE_UINT|CTLFLAG_RD,
339 	&cnt.v_page_size, 0, vcnt, "IU", "");
340 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_page_count, CTLTYPE_UINT|CTLFLAG_RD,
341 	&cnt.v_page_count, 0, vcnt, "IU", "");
342 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_reserved, CTLTYPE_UINT|CTLFLAG_RD,
343 	&cnt.v_free_reserved, 0, vcnt, "IU", "");
344 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_target, CTLTYPE_UINT|CTLFLAG_RD,
345 	&cnt.v_free_target, 0, vcnt, "IU", "");
346 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_min, CTLTYPE_UINT|CTLFLAG_RD,
347 	&cnt.v_free_min, 0, vcnt, "IU", "");
348 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_free_count, CTLTYPE_UINT|CTLFLAG_RD,
349 	&cnt.v_free_count, 0, vcnt, "IU", "");
350 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_wire_count, CTLTYPE_UINT|CTLFLAG_RD,
351 	&cnt.v_wire_count, 0, vcnt, "IU", "");
352 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_active_count, CTLTYPE_UINT|CTLFLAG_RD,
353 	&cnt.v_active_count, 0, vcnt, "IU", "");
354 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_inactive_target, CTLTYPE_UINT|CTLFLAG_RD,
355 	&cnt.v_inactive_target, 0, vcnt, "IU", "");
356 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_inactive_count, CTLTYPE_UINT|CTLFLAG_RD,
357 	&cnt.v_inactive_count, 0, vcnt, "IU", "");
358 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cache_count, CTLTYPE_UINT|CTLFLAG_RD,
359 	&cnt.v_cache_count, 0, vcnt, "IU", "");
360 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cache_min, CTLTYPE_UINT|CTLFLAG_RD,
361 	&cnt.v_cache_min, 0, vcnt, "IU", "");
362 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_cache_max, CTLTYPE_UINT|CTLFLAG_RD,
363 	&cnt.v_cache_max, 0, vcnt, "IU", "");
364 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_pageout_free_min, CTLTYPE_UINT|CTLFLAG_RD,
365 	&cnt.v_pageout_free_min, 0, vcnt, "IU", "");
366 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_interrupt_free_min, CTLTYPE_UINT|CTLFLAG_RD,
367 	&cnt.v_interrupt_free_min, 0, vcnt, "IU", "");
368 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_forks, CTLTYPE_UINT|CTLFLAG_RD,
369 	&cnt.v_forks, 0, vcnt, "IU", "Number of fork() calls");
370 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vforks, CTLTYPE_UINT|CTLFLAG_RD,
371 	&cnt.v_vforks, 0, vcnt, "IU", "Number of vfork() calls");
372 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_rforks, CTLTYPE_UINT|CTLFLAG_RD,
373 	&cnt.v_rforks, 0, vcnt, "IU", "Number of rfork() calls");
374 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_kthreads, CTLTYPE_UINT|CTLFLAG_RD,
375 	&cnt.v_kthreads, 0, vcnt, "IU", "Number of fork() calls by kernel");
376 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_forkpages, CTLTYPE_UINT|CTLFLAG_RD,
377 	&cnt.v_forkpages, 0, vcnt, "IU", "VM pages affected by fork()");
378 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_vforkpages, CTLTYPE_UINT|CTLFLAG_RD,
379 	&cnt.v_vforkpages, 0, vcnt, "IU", "VM pages affected by vfork()");
380 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_rforkpages, CTLTYPE_UINT|CTLFLAG_RD,
381 	&cnt.v_rforkpages, 0, vcnt, "IU", "VM pages affected by rfork()");
382 SYSCTL_PROC(_vm_stats_vm, OID_AUTO, v_kthreadpages, CTLTYPE_UINT|CTLFLAG_RD,
383 	&cnt.v_kthreadpages, 0, vcnt, "IU", "VM pages affected by fork() by kernel");
384 
385 SYSCTL_INT(_vm_stats_misc, OID_AUTO,
386 	zero_page_count, CTLFLAG_RD, &vm_page_zero_count, 0, "");
387 #if 0
388 SYSCTL_INT(_vm_stats_misc, OID_AUTO,
389 	page_mask, CTLFLAG_RD, &page_mask, 0, "");
390 SYSCTL_INT(_vm_stats_misc, OID_AUTO,
391 	page_shift, CTLFLAG_RD, &page_shift, 0, "");
392 SYSCTL_INT(_vm_stats_misc, OID_AUTO,
393 	first_page, CTLFLAG_RD, &first_page, 0, "");
394 SYSCTL_INT(_vm_stats_misc, OID_AUTO,
395 	last_page, CTLFLAG_RD, &last_page, 0, "");
396 #endif
397