vm_meter.c revision 302243
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: stable/10/sys/vm/vm_meter.c 302243 2016-06-28 00:37:34Z kib $");
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/rwlock.h>
43#include <sys/sx.h>
44#include <sys/vmmeter.h>
45#include <sys/smp.h>
46
47#include <vm/vm.h>
48#include <vm/vm_page.h>
49#include <vm/vm_extern.h>
50#include <vm/vm_param.h>
51#include <vm/pmap.h>
52#include <vm/vm_map.h>
53#include <vm/vm_object.h>
54#include <sys/sysctl.h>
55
56struct vmmeter cnt;
57
58SYSCTL_UINT(_vm, VM_V_FREE_MIN, v_free_min,
59	CTLFLAG_RW, &cnt.v_free_min, 0, "Minimum low-free-pages threshold");
60SYSCTL_UINT(_vm, VM_V_FREE_TARGET, v_free_target,
61	CTLFLAG_RW, &cnt.v_free_target, 0, "Desired free pages");
62SYSCTL_UINT(_vm, VM_V_FREE_RESERVED, v_free_reserved,
63	CTLFLAG_RW, &cnt.v_free_reserved, 0, "Pages reserved for deadlock");
64SYSCTL_UINT(_vm, VM_V_INACTIVE_TARGET, v_inactive_target,
65	CTLFLAG_RW, &cnt.v_inactive_target, 0, "Pages desired inactive");
66SYSCTL_UINT(_vm, VM_V_CACHE_MIN, v_cache_min,
67	CTLFLAG_RW, &cnt.v_cache_min, 0, "Min pages on cache queue");
68SYSCTL_UINT(_vm, VM_V_CACHE_MAX, v_cache_max,
69	CTLFLAG_RW, &cnt.v_cache_max, 0, "Max pages on cache queue");
70SYSCTL_UINT(_vm, VM_V_PAGEOUT_FREE_MIN, v_pageout_free_min,
71	CTLFLAG_RW, &cnt.v_pageout_free_min, 0, "Min pages reserved for kernel");
72SYSCTL_UINT(_vm, OID_AUTO, v_free_severe,
73	CTLFLAG_RW, &cnt.v_free_severe, 0, "Severe page depletion point");
74
75static int
76sysctl_vm_loadavg(SYSCTL_HANDLER_ARGS)
77{
78
79#ifdef SCTL_MASK32
80	u_int32_t la[4];
81
82	if (req->flags & SCTL_MASK32) {
83		la[0] = averunnable.ldavg[0];
84		la[1] = averunnable.ldavg[1];
85		la[2] = averunnable.ldavg[2];
86		la[3] = averunnable.fscale;
87		return SYSCTL_OUT(req, la, sizeof(la));
88	} else
89#endif
90		return SYSCTL_OUT(req, &averunnable, sizeof(averunnable));
91}
92SYSCTL_PROC(_vm, VM_LOADAVG, loadavg, CTLTYPE_STRUCT | CTLFLAG_RD |
93    CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_loadavg, "S,loadavg",
94    "Machine loadaverage history");
95
96/*
97 * This function aims to determine if the object is mapped,
98 * specifically, if it is referenced by a vm_map_entry.  Because
99 * objects occasionally acquire transient references that do not
100 * represent a mapping, the method used here is inexact.  However, it
101 * has very low overhead and is good enough for the advisory
102 * vm.vmtotal sysctl.
103 */
104static bool
105is_object_active(vm_object_t obj)
106{
107
108	return (obj->ref_count > obj->shadow_count);
109}
110
111static int
112vmtotal(SYSCTL_HANDLER_ARGS)
113{
114	struct vmtotal total;
115	vm_object_t object;
116	struct proc *p;
117	struct thread *td;
118
119	bzero(&total, sizeof(total));
120
121	/*
122	 * Calculate process statistics.
123	 */
124	sx_slock(&allproc_lock);
125	FOREACH_PROC_IN_SYSTEM(p) {
126		if (p->p_flag & P_SYSTEM)
127			continue;
128		PROC_LOCK(p);
129		switch (p->p_state) {
130		case PRS_NEW:
131			PROC_UNLOCK(p);
132			continue;
133			break;
134		default:
135			FOREACH_THREAD_IN_PROC(p, td) {
136				thread_lock(td);
137				switch (td->td_state) {
138				case TDS_INHIBITED:
139					if (TD_IS_SWAPPED(td))
140						total.t_sw++;
141					else if (TD_IS_SLEEPING(td)) {
142						if (td->td_priority <= PZERO)
143							total.t_dw++;
144						else
145							total.t_sl++;
146						if (td->td_wchan ==
147						    &cnt.v_free_count)
148							total.t_pw++;
149					}
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	sx_sunlock(&allproc_lock);
169	/*
170	 * Calculate object memory usage statistics.
171	 */
172	mtx_lock(&vm_object_list_mtx);
173	TAILQ_FOREACH(object, &vm_object_list, object_list) {
174		/*
175		 * Perform unsynchronized reads on the object.  In
176		 * this case, the lack of synchronization should not
177		 * impair the accuracy of the reported statistics.
178		 */
179		if ((object->flags & OBJ_FICTITIOUS) != 0) {
180			/*
181			 * Devices, like /dev/mem, will badly skew our totals.
182			 */
183			continue;
184		}
185		if (object->ref_count == 0) {
186			/*
187			 * Also skip unreferenced objects, including
188			 * vnodes representing mounted file systems.
189			 */
190			continue;
191		}
192		if (object->ref_count == 1 &&
193		    (object->flags & OBJ_NOSPLIT) != 0) {
194			/*
195			 * Also skip otherwise unreferenced swap
196			 * objects backing tmpfs vnodes, and POSIX or
197			 * SysV shared memory.
198			 */
199			continue;
200		}
201		total.t_vm += object->size;
202		total.t_rm += object->resident_page_count;
203		if (is_object_active(object)) {
204			total.t_avm += object->size;
205			total.t_arm += object->resident_page_count;
206		}
207		if (object->shadow_count > 1) {
208			/* shared object */
209			total.t_vmshr += object->size;
210			total.t_rmshr += object->resident_page_count;
211			if (is_object_active(object)) {
212				total.t_avmshr += object->size;
213				total.t_armshr += object->resident_page_count;
214			}
215		}
216	}
217	mtx_unlock(&vm_object_list_mtx);
218	total.t_free = cnt.v_free_count + cnt.v_cache_count;
219	return (sysctl_handle_opaque(oidp, &total, sizeof(total), req));
220}
221
222/*
223 * vcnt() -	accumulate statistics from all cpus and the global cnt
224 *		structure.
225 *
226 *	The vmmeter structure is now per-cpu as well as global.  Those
227 *	statistics which can be kept on a per-cpu basis (to avoid cache
228 *	stalls between cpus) can be moved to the per-cpu vmmeter.  Remaining
229 *	statistics, such as v_free_reserved, are left in the global
230 *	structure.
231 *
232 * (sysctl_oid *oidp, void *arg1, int arg2, struct sysctl_req *req)
233 */
234static int
235vcnt(SYSCTL_HANDLER_ARGS)
236{
237	int count = *(int *)arg1;
238	int offset = (char *)arg1 - (char *)&cnt;
239	int i;
240
241	CPU_FOREACH(i) {
242		struct pcpu *pcpu = pcpu_find(i);
243		count += *(int *)((char *)&pcpu->pc_cnt + offset);
244	}
245	return (SYSCTL_OUT(req, &count, sizeof(int)));
246}
247
248SYSCTL_PROC(_vm, VM_TOTAL, vmtotal, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
249    0, sizeof(struct vmtotal), vmtotal, "S,vmtotal",
250    "System virtual memory statistics");
251SYSCTL_NODE(_vm, OID_AUTO, stats, CTLFLAG_RW, 0, "VM meter stats");
252static SYSCTL_NODE(_vm_stats, OID_AUTO, sys, CTLFLAG_RW, 0,
253	"VM meter sys stats");
254static SYSCTL_NODE(_vm_stats, OID_AUTO, vm, CTLFLAG_RW, 0,
255	"VM meter vm stats");
256SYSCTL_NODE(_vm_stats, OID_AUTO, misc, CTLFLAG_RW, 0, "VM meter misc stats");
257
258#define	VM_STATS(parent, var, descr) \
259	SYSCTL_PROC(parent, OID_AUTO, var, \
260	    CTLTYPE_UINT | CTLFLAG_RD | CTLFLAG_MPSAFE, &cnt.var, 0, vcnt, \
261	    "IU", descr)
262#define	VM_STATS_VM(var, descr)		VM_STATS(_vm_stats_vm, var, descr)
263#define	VM_STATS_SYS(var, descr)	VM_STATS(_vm_stats_sys, var, descr)
264
265VM_STATS_SYS(v_swtch, "Context switches");
266VM_STATS_SYS(v_trap, "Traps");
267VM_STATS_SYS(v_syscall, "System calls");
268VM_STATS_SYS(v_intr, "Device interrupts");
269VM_STATS_SYS(v_soft, "Software interrupts");
270VM_STATS_VM(v_vm_faults, "Address memory faults");
271VM_STATS_VM(v_io_faults, "Page faults requiring I/O");
272VM_STATS_VM(v_cow_faults, "Copy-on-write faults");
273VM_STATS_VM(v_cow_optim, "Optimized COW faults");
274VM_STATS_VM(v_zfod, "Pages zero-filled on demand");
275VM_STATS_VM(v_ozfod, "Optimized zero fill pages");
276VM_STATS_VM(v_swapin, "Swap pager pageins");
277VM_STATS_VM(v_swapout, "Swap pager pageouts");
278VM_STATS_VM(v_swappgsin, "Swap pages swapped in");
279VM_STATS_VM(v_swappgsout, "Swap pages swapped out");
280VM_STATS_VM(v_vnodein, "Vnode pager pageins");
281VM_STATS_VM(v_vnodeout, "Vnode pager pageouts");
282VM_STATS_VM(v_vnodepgsin, "Vnode pages paged in");
283VM_STATS_VM(v_vnodepgsout, "Vnode pages paged out");
284VM_STATS_VM(v_intrans, "In transit page faults");
285VM_STATS_VM(v_reactivated, "Pages reactivated from free list");
286VM_STATS_VM(v_pdwakeups, "Pagedaemon wakeups");
287VM_STATS_VM(v_pdpages, "Pages analyzed by pagedaemon");
288VM_STATS_VM(v_tcached, "Total pages cached");
289VM_STATS_VM(v_dfree, "Pages freed by pagedaemon");
290VM_STATS_VM(v_pfree, "Pages freed by exiting processes");
291VM_STATS_VM(v_tfree, "Total pages freed");
292VM_STATS_VM(v_page_size, "Page size in bytes");
293VM_STATS_VM(v_page_count, "Total number of pages in system");
294VM_STATS_VM(v_free_reserved, "Pages reserved for deadlock");
295VM_STATS_VM(v_free_target, "Pages desired free");
296VM_STATS_VM(v_free_min, "Minimum low-free-pages threshold");
297VM_STATS_VM(v_free_count, "Free pages");
298VM_STATS_VM(v_wire_count, "Wired pages");
299VM_STATS_VM(v_active_count, "Active pages");
300VM_STATS_VM(v_inactive_target, "Desired inactive pages");
301VM_STATS_VM(v_inactive_count, "Inactive pages");
302VM_STATS_VM(v_cache_count, "Pages on cache queue");
303VM_STATS_VM(v_cache_min, "Min pages on cache queue");
304VM_STATS_VM(v_cache_max, "Max pages on cached queue");
305VM_STATS_VM(v_pageout_free_min, "Min pages reserved for kernel");
306VM_STATS_VM(v_interrupt_free_min, "Reserved pages for interrupt code");
307VM_STATS_VM(v_forks, "Number of fork() calls");
308VM_STATS_VM(v_vforks, "Number of vfork() calls");
309VM_STATS_VM(v_rforks, "Number of rfork() calls");
310VM_STATS_VM(v_kthreads, "Number of fork() calls by kernel");
311VM_STATS_VM(v_forkpages, "VM pages affected by fork()");
312VM_STATS_VM(v_vforkpages, "VM pages affected by vfork()");
313VM_STATS_VM(v_rforkpages, "VM pages affected by rfork()");
314VM_STATS_VM(v_kthreadpages, "VM pages affected by fork() by kernel");
315
316SYSCTL_INT(_vm_stats_misc, OID_AUTO, zero_page_count, CTLFLAG_RD,
317	&vm_page_zero_count, 0, "Number of zero-ed free pages");
318