xref: /netbsd-src/usr.bin/systat/bufcache.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: bufcache.c,v 1.22 2008/04/28 20:24:15 martin Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Simon Burge.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __RCSID("$NetBSD: bufcache.c,v 1.22 2008/04/28 20:24:15 martin Exp $");
35 #endif /* not lint */
36 
37 #include <sys/param.h>
38 #include <sys/buf.h>
39 #include <sys/mount.h>
40 #include <sys/sysctl.h>
41 #include <sys/vnode.h>
42 
43 #include <uvm/uvm_extern.h>
44 
45 #include <err.h>
46 #include <errno.h>
47 #include <inttypes.h>
48 #include <math.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include <stdbool.h>
53 
54 #include <miscfs/specfs/specdev.h>
55 
56 #include "systat.h"
57 #include "extern.h"
58 
59 #define VCACHE_SIZE	50
60 #define	PAGEINFO_ROWS	 5
61 
62 struct vcache {
63 	int vc_age;
64 	struct vnode *vc_addr;
65 	struct vnode vc_node;
66 };
67 
68 struct ml_entry {
69 	u_int ml_count;
70 	u_long ml_size;
71 	u_long ml_valid;
72 	struct mount *ml_addr;
73 	LIST_ENTRY(ml_entry) ml_entries;
74 	struct mount ml_mount;
75 };
76 
77 static struct nlist namelist[] = {
78 #define	X_BUFMEM	0
79 	{ .n_name = "_bufmem" },
80 	{ .n_name = NULL },
81 };
82 
83 static struct vcache vcache[VCACHE_SIZE];
84 static LIST_HEAD(mount_list, ml_entry) mount_list;
85 
86 static u_long bufmem;
87 static u_int nbuf, pgwidth, kbwidth;
88 static struct uvmexp_sysctl uvmexp;
89 
90 static void	vc_init(void);
91 static void	ml_init(void);
92 static struct 	vnode *vc_lookup(struct vnode *);
93 static struct 	mount *ml_lookup(struct mount *, int, int);
94 static void	fetchuvmexp(void);
95 
96 
97 WINDOW *
98 openbufcache(void)
99 {
100 
101 	return (subwin(stdscr, -1, 0, 5, 0));
102 }
103 
104 void
105 closebufcache(WINDOW *w)
106 {
107 
108 	if (w == NULL)
109 		return;
110 	wclear(w);
111 	wrefresh(w);
112 	delwin(w);
113 	ml_init();		/* Clear out mount list */
114 }
115 
116 void
117 labelbufcache(void)
118 {
119 	int i;
120 
121 	for (i = 0; i <= PAGEINFO_ROWS; i++) {
122 		wmove(wnd, i, 0);
123 		wclrtoeol(wnd);
124 	}
125 	mvwaddstr(wnd, PAGEINFO_ROWS + 1, 0, "File System          Bufs used"
126 	    "   %   kB in use   %  Bufsize kB   %  Util %");
127 	wclrtoeol(wnd);
128 }
129 
130 void
131 showbufcache(void)
132 {
133 	int tbuf, i, lastrow;
134 	double tvalid, tsize;
135 	struct ml_entry *ml;
136 
137 	NREAD(X_BUFMEM, &bufmem, sizeof(bufmem));
138 
139 	mvwprintw(wnd, 0, 0,
140 	    "   %*d metadata buffers using             %*ld kBytes of "
141 	    "memory (%2.0f%%).",
142 	    pgwidth, nbuf, kbwidth, bufmem / 1024,
143 	    ((bufmem * 100.0) + 0.5) / getpagesize() / uvmexp.npages);
144 	wclrtoeol(wnd);
145 	mvwprintw(wnd, 1, 0,
146 	    "   %*" PRIu64 " pages for cached file data using   %*"
147 	    PRIu64 " kBytes of memory (%2.0f%%).",
148 	    pgwidth, uvmexp.filepages,
149 	    kbwidth, uvmexp.filepages * getpagesize() / 1024,
150 	    (uvmexp.filepages * 100 + 0.5) / uvmexp.npages);
151 	wclrtoeol(wnd);
152 	mvwprintw(wnd, 2, 0,
153 	    "   %*" PRIu64 " pages for executables using        %*"
154 	    PRIu64 " kBytes of memory (%2.0f%%).",
155 	    pgwidth, uvmexp.execpages,
156 	    kbwidth, uvmexp.execpages * getpagesize() / 1024,
157 	    (uvmexp.execpages * 100 + 0.5) / uvmexp.npages);
158 	wclrtoeol(wnd);
159 	mvwprintw(wnd, 3, 0,
160 	    "   %*" PRIu64 " pages for anon (non-file) data     %*"
161 	    PRIu64 " kBytes of memory (%2.0f%%).",
162 	    pgwidth, uvmexp.anonpages,
163 	    kbwidth, uvmexp.anonpages * getpagesize() / 1024,
164 	    (uvmexp.anonpages * 100 + 0.5) / uvmexp.npages);
165 	wclrtoeol(wnd);
166 	mvwprintw(wnd, 4, 0,
167 	    "   %*" PRIu64 " free pages                         %*"
168 	    PRIu64 " kBytes of memory (%2.0f%%).",
169 	    pgwidth, uvmexp.free,
170 	    kbwidth, uvmexp.free * getpagesize() / 1024,
171 	    (uvmexp.free * 100 + 0.5) / uvmexp.npages);
172 	wclrtoeol(wnd);
173 
174 	if (nbuf == 0 || bufmem == 0) {
175 		wclrtobot(wnd);
176 		return;
177 	}
178 
179 	tbuf = 0;
180 	tvalid = tsize = 0;
181 	lastrow = PAGEINFO_ROWS + 2;	/* Leave room for header. */
182 	for (i = lastrow, ml = LIST_FIRST(&mount_list); ml != NULL;
183 	    i++, ml = LIST_NEXT(ml, ml_entries)) {
184 
185 		int cnt = ml->ml_count;
186 		double v = ml->ml_valid;
187 		double s = ml->ml_size;
188 
189 		/* Display in window if enough room. */
190 		if (i < getmaxy(wnd) - 2) {
191 			mvwprintw(wnd, i, 0, "%-20.20s", ml->ml_addr == NULL ?
192 			    "NULL" : ml->ml_mount.mnt_stat.f_mntonname);
193 			wprintw(wnd,
194 			    "    %6d %3d    %8ld %3.0f    %8ld %3.0f     %3.0f",
195 			    cnt, (100 * cnt) / nbuf,
196 			    (long)(v/1024), 100 * v / bufmem,
197 			    (long)(s/1024), 100 * s / bufmem,
198 			    100 * v / s);
199 			wclrtoeol(wnd);
200 			lastrow = i;
201 		}
202 
203 		/* Update statistics. */
204 		tbuf += cnt;
205 		tvalid += v;
206 		tsize += s;
207 	}
208 
209 	wclrtobot(wnd);
210 	mvwprintw(wnd, lastrow + 2, 0,
211 	    "%-20s    %6d %3d    %8ld %3.0f    %8ld %3.0f     %3.0f",
212 	    "Total:", tbuf, (100 * tbuf) / nbuf,
213 	    (long)(tvalid/1024), 100 * tvalid / bufmem,
214 	    (long)(tsize/1024), 100 * tsize / bufmem,
215 	    tsize != 0 ? ((100 * tvalid) / tsize) : 0);
216 }
217 
218 int
219 initbufcache(void)
220 {
221 	if (namelist[0].n_type == 0) {
222 		if (kvm_nlist(kd, namelist)) {
223 			nlisterr(namelist);
224 			return(0);
225 		}
226 	}
227 
228 	fetchuvmexp();
229 	pgwidth = (int)(floor(log10((double)uvmexp.npages)) + 1);
230 	kbwidth = (int)(floor(log10(uvmexp.npages * getpagesize() / 1024.0)) +
231 	    1);
232 
233 	return(1);
234 }
235 
236 static void
237 fetchuvmexp(void)
238 {
239 	int mib[2];
240 	size_t size;
241 
242 	/* Re-read pages used for vnodes & executables */
243 	size = sizeof(uvmexp);
244 	mib[0] = CTL_VM;
245 	mib[1] = VM_UVMEXP2;
246 	if (sysctl(mib, 2, &uvmexp, &size, NULL, 0) < 0) {
247 		error("can't get uvmexp: %s\n", strerror(errno));
248 		memset(&uvmexp, 0, sizeof(uvmexp));
249 	}
250 }
251 
252 void
253 fetchbufcache(void)
254 {
255 	int count;
256 	struct buf_sysctl *bp, *buffers;
257 	struct vnode *vn;
258 	struct mount *mt;
259 	struct ml_entry *ml;
260 	int mib[6];
261 	size_t size;
262 	int extraslop = 0;
263 
264 	/* Re-read pages used for vnodes & executables */
265 	fetchuvmexp();
266 
267 	/* Initialise vnode cache and mount list. */
268 	vc_init();
269 	ml_init();
270 
271 	/* Get metadata buffers */
272 	size = 0;
273 	buffers = NULL;
274 	mib[0] = CTL_KERN;
275 	mib[1] = KERN_BUF;
276 	mib[2] = KERN_BUF_ALL;
277 	mib[3] = KERN_BUF_ALL;
278 	mib[4] = (int)sizeof(struct buf_sysctl);
279 	mib[5] = INT_MAX; /* we want them all */
280 again:
281 	if (sysctl(mib, 6, NULL, &size, NULL, 0) < 0) {
282 		error("can't get buffers size: %s\n", strerror(errno));
283 		return;
284 	}
285 	if (size == 0)
286 		return;
287 
288 	size += extraslop * sizeof(struct buf_sysctl);
289 	buffers = malloc(size);
290 	if (buffers == NULL) {
291 		error("can't allocate buffers: %s\n", strerror(errno));
292 		return;
293 	}
294 	if (sysctl(mib, 6, buffers, &size, NULL, 0) < 0) {
295 		free(buffers);
296 		if (extraslop == 0) {
297 			extraslop = 100;
298 			goto again;
299 		}
300 		error("can't get buffers: %s\n", strerror(errno));
301 		return;
302 	}
303 
304 	nbuf = size / sizeof(struct buf_sysctl);
305 	for (bp = buffers; bp < buffers + nbuf; bp++) {
306 		if (UINT64TOPTR(bp->b_vp) != NULL) {
307 			struct mount *mp;
308 			vn = vc_lookup(UINT64TOPTR(bp->b_vp));
309 			if (vn == NULL)
310 				break;
311 
312 			mp = vn->v_mount;
313 			/*
314 			 * References to mounted-on vnodes should be
315 			 * counted towards the mounted filesystem.
316 			 */
317 			if (vn->v_type == VBLK && vn->v_specnode != NULL) {
318 				specnode_t sn;
319 				specdev_t sd;
320 				if (!KREAD(vn->v_specnode, &sn, sizeof(sn)))
321 					continue;
322 				if (!KREAD(sn.sn_dev, &sd, sizeof(sd)))
323 					continue;
324 				if (sd.sd_mountpoint)
325 					mp = sd.sd_mountpoint;
326 			}
327 			if (mp != NULL)
328 				mt = ml_lookup(mp,
329 				    bp->b_bufsize,
330 				    bp->b_bcount);
331 		}
332 	}
333 
334 	/* simple sort - there's not that many entries */
335 	do {
336 		if ((ml = LIST_FIRST(&mount_list)) == NULL ||
337 		    LIST_NEXT(ml, ml_entries) == NULL)
338 			break;
339 
340 		count = 0;
341 		for (ml = LIST_FIRST(&mount_list); ml != NULL;
342 		    ml = LIST_NEXT(ml, ml_entries)) {
343 			if (LIST_NEXT(ml, ml_entries) == NULL)
344 				break;
345 			if (ml->ml_count < LIST_NEXT(ml, ml_entries)->ml_count) {
346 				ml = LIST_NEXT(ml, ml_entries);
347 				LIST_REMOVE(ml, ml_entries);
348 				LIST_INSERT_HEAD(&mount_list, ml, ml_entries);
349 				count++;
350 			}
351 		}
352 	} while (count != 0);
353 
354 	free(buffers);
355 }
356 
357 static void
358 vc_init(void)
359 {
360 	int i;
361 
362 	/* vc_addr == NULL for unused cache entry. */
363 	for (i = 0; i < VCACHE_SIZE; i++)
364 		vcache[i].vc_addr = NULL;
365 }
366 
367 static void
368 ml_init(void)
369 {
370 	struct ml_entry *ml;
371 
372 	/* Throw out the current mount list and start again. */
373 	while ((ml = LIST_FIRST(&mount_list)) != NULL) {
374 		LIST_REMOVE(ml, ml_entries);
375 		free(ml);
376 	}
377 }
378 
379 
380 static struct vnode *
381 vc_lookup(struct vnode *vaddr)
382 {
383 	struct vnode *ret;
384 	size_t i, oldest;
385 
386 	ret = NULL;
387 	oldest = 0;
388 	for (i = 0; i < VCACHE_SIZE; i++) {
389 		if (vcache[i].vc_addr == NULL)
390 			break;
391 		vcache[i].vc_age++;
392 		if (vcache[i].vc_age < vcache[oldest].vc_age)
393 			oldest = i;
394 		if (vcache[i].vc_addr == vaddr) {
395 			vcache[i].vc_age = 0;
396 			ret = &vcache[i].vc_node;
397 		}
398 	}
399 
400 	/* Find an entry in the cache? */
401 	if (ret != NULL)
402 		return(ret);
403 
404 	/* Go past the end of the cache? */
405 	if  (i >= VCACHE_SIZE)
406 		i = oldest;
407 
408 	/* Read in new vnode and reset age counter. */
409 	if (KREAD(vaddr, &vcache[i].vc_node, sizeof(struct vnode)) == 0)
410 		return NULL;
411 	vcache[i].vc_addr = vaddr;
412 	vcache[i].vc_age = 0;
413 
414 	return(&vcache[i].vc_node);
415 }
416 
417 static struct mount *
418 ml_lookup(struct mount *maddr, int size, int valid)
419 {
420 	struct ml_entry *ml;
421 
422 	for (ml = LIST_FIRST(&mount_list); ml != NULL;
423 	    ml = LIST_NEXT(ml, ml_entries))
424 		if (ml->ml_addr == maddr) {
425 			ml->ml_count++;
426 			ml->ml_size += size;
427 			ml->ml_valid += valid;
428 			if (ml->ml_addr == NULL)
429 				return(NULL);
430 			else
431 				return(&ml->ml_mount);
432 		}
433 
434 	if ((ml = malloc(sizeof(struct ml_entry))) == NULL) {
435 		error("out of memory");
436 		die(0);
437 	}
438 	LIST_INSERT_HEAD(&mount_list, ml, ml_entries);
439 	ml->ml_count = 1;
440 	ml->ml_size = size;
441 	ml->ml_valid = valid;
442 	ml->ml_addr = maddr;
443 	if (maddr == NULL)
444 		return(NULL);
445 
446 	KREAD(maddr, &ml->ml_mount, sizeof(struct mount));
447 	return(&ml->ml_mount);
448 }
449