xref: /netbsd-src/usr.bin/systat/bufcache.c (revision db6316d1518382eecd2fdbe55a1205e0620a1b35)
1 /*	$NetBSD: bufcache.c,v 1.18 2004/11/23 03:11:33 simonb 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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #ifndef lint
41 __RCSID("$NetBSD: bufcache.c,v 1.18 2004/11/23 03:11:33 simonb Exp $");
42 #endif /* not lint */
43 
44 #include <sys/param.h>
45 #include <sys/buf.h>
46 #include <sys/mount.h>
47 #include <sys/sysctl.h>
48 #include <sys/vnode.h>
49 
50 #include <uvm/uvm_extern.h>
51 
52 #include <err.h>
53 #include <errno.h>
54 #include <inttypes.h>
55 #include <kvm.h>
56 #include <math.h>
57 #include <nlist.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61 
62 #include <miscfs/specfs/specdev.h>
63 
64 #include "systat.h"
65 #include "extern.h"
66 
67 #define VCACHE_SIZE	50
68 #define	PAGEINFO_ROWS	 5
69 
70 struct vcache {
71 	int vc_age;
72 	struct vnode *vc_addr;
73 	struct vnode vc_node;
74 };
75 
76 struct ml_entry {
77 	u_int ml_count;
78 	u_long ml_size;
79 	u_long ml_valid;
80 	struct mount *ml_addr;
81 	LIST_ENTRY(ml_entry) ml_entries;
82 	struct mount ml_mount;
83 };
84 
85 static struct nlist namelist[] = {
86 #define	X_BUFMEM	0
87 	{ "_bufmem" },
88 	{ "" },
89 };
90 
91 static struct vcache vcache[VCACHE_SIZE];
92 static LIST_HEAD(mount_list, ml_entry) mount_list;
93 
94 static u_long bufmem;
95 static u_int nbuf, pgwidth, kbwidth;
96 static struct uvmexp_sysctl uvmexp;
97 
98 static void	vc_init(void);
99 static void	ml_init(void);
100 static struct 	vnode *vc_lookup(struct vnode *);
101 static struct 	mount *ml_lookup(struct mount *, int, int);
102 static void	fetchuvmexp(void);
103 
104 
105 WINDOW *
106 openbufcache(void)
107 {
108 
109 	return (subwin(stdscr, -1, 0, 5, 0));
110 }
111 
112 void
113 closebufcache(WINDOW *w)
114 {
115 
116 	if (w == NULL)
117 		return;
118 	wclear(w);
119 	wrefresh(w);
120 	delwin(w);
121 	ml_init();		/* Clear out mount list */
122 }
123 
124 void
125 labelbufcache(void)
126 {
127 	int i;
128 
129 	for (i = 0; i <= PAGEINFO_ROWS; i++) {
130 		wmove(wnd, i, 0);
131 		wclrtoeol(wnd);
132 	}
133 	mvwaddstr(wnd, PAGEINFO_ROWS + 1, 0, "File System          Bufs used"
134 	    "   %   kB in use   %  Bufsize kB   %  Util %");
135 	wclrtoeol(wnd);
136 }
137 
138 void
139 showbufcache(void)
140 {
141 	int tbuf, i, lastrow;
142 	double tvalid, tsize;
143 	struct ml_entry *ml;
144 
145 	NREAD(X_BUFMEM, &bufmem, sizeof(bufmem));
146 
147 	mvwprintw(wnd, 0, 0,
148 	    "   %*d metadata buffers using             %*ld kBytes of "
149 	    "memory (%2.0f%%).",
150 	    pgwidth, nbuf, kbwidth, bufmem / 1024,
151 	    ((bufmem * 100.0) + 0.5) / getpagesize() / uvmexp.npages);
152 	wclrtoeol(wnd);
153 	mvwprintw(wnd, 1, 0,
154 	    "   %*" PRIu64 " pages for cached file data using   %*"
155 	    PRIu64 " kBytes of memory (%2.0f%%).",
156 	    pgwidth, uvmexp.filepages,
157 	    kbwidth, uvmexp.filepages * getpagesize() / 1024,
158 	    (uvmexp.filepages * 100 + 0.5) / uvmexp.npages);
159 	wclrtoeol(wnd);
160 	mvwprintw(wnd, 2, 0,
161 	    "   %*" PRIu64 " pages for executables using        %*"
162 	    PRIu64 " kBytes of memory (%2.0f%%).",
163 	    pgwidth, uvmexp.execpages,
164 	    kbwidth, uvmexp.execpages * getpagesize() / 1024,
165 	    (uvmexp.execpages * 100 + 0.5) / uvmexp.npages);
166 	wclrtoeol(wnd);
167 	mvwprintw(wnd, 3, 0,
168 	    "   %*" PRIu64 " pages for anon (non-file) data     %*"
169 	    PRIu64 " kBytes of memory (%2.0f%%).",
170 	    pgwidth, uvmexp.anonpages,
171 	    kbwidth, uvmexp.anonpages * getpagesize() / 1024,
172 	    (uvmexp.anonpages * 100 + 0.5) / uvmexp.npages);
173 	wclrtoeol(wnd);
174 	mvwprintw(wnd, 4, 0,
175 	    "   %*" PRIu64 " free pages                         %*"
176 	    PRIu64 " kBytes of memory (%2.0f%%).",
177 	    pgwidth, uvmexp.free,
178 	    kbwidth, uvmexp.free * getpagesize() / 1024,
179 	    (uvmexp.free * 100 + 0.5) / uvmexp.npages);
180 	wclrtoeol(wnd);
181 
182 	if (nbuf == 0 || bufmem == 0) {
183 		wclrtobot(wnd);
184 		return;
185 	}
186 
187 	tbuf = 0;
188 	tvalid = tsize = 0;
189 	lastrow = PAGEINFO_ROWS + 2;	/* Leave room for header. */
190 	for (i = lastrow, ml = LIST_FIRST(&mount_list); ml != NULL;
191 	    i++, ml = LIST_NEXT(ml, ml_entries)) {
192 
193 		int c = ml->ml_count;
194 		double v = ml->ml_valid;
195 		double s = ml->ml_size;
196 
197 		/* Display in window if enough room. */
198 		if (i < getmaxy(wnd) - 2) {
199 			mvwprintw(wnd, i, 0, "%-20.20s", ml->ml_addr == NULL ?
200 			    "NULL" : ml->ml_mount.mnt_stat.f_mntonname);
201 			wprintw(wnd,
202 			    "    %6d %3d    %8ld %3.0f    %8ld %3.0f     %3.0f",
203 			    c, (100 * c) / nbuf,
204 			    (long)(v/1024), 100 * v / bufmem,
205 			    (long)(s/1024), 100 * s / bufmem,
206 			    100 * v / s);
207 			wclrtoeol(wnd);
208 			lastrow = i;
209 		}
210 
211 		/* Update statistics. */
212 		tbuf += c;
213 		tvalid += v;
214 		tsize += s;
215 	}
216 
217 	wclrtobot(wnd);
218 	mvwprintw(wnd, lastrow + 2, 0,
219 	    "%-20s    %6d %3d    %8ld %3.0f    %8ld %3.0f     %3.0f",
220 	    "Total:", tbuf, (100 * tbuf) / nbuf,
221 	    (long)(tvalid/1024), 100 * tvalid / bufmem,
222 	    (long)(tsize/1024), 100 * tsize / bufmem,
223 	    tsize != 0 ? ((100 * tvalid) / tsize) : 0);
224 }
225 
226 int
227 initbufcache(void)
228 {
229 	if (namelist[0].n_type == 0) {
230 		if (kvm_nlist(kd, namelist)) {
231 			nlisterr(namelist);
232 			return(0);
233 		}
234 	}
235 
236 	fetchuvmexp();
237 	pgwidth = (int)(floor(log10((double)uvmexp.npages)) + 1);
238 	kbwidth = (int)(floor(log10(uvmexp.npages * getpagesize() / 1024.0)) +
239 	    1);
240 
241 	return(1);
242 }
243 
244 static void
245 fetchuvmexp(void)
246 {
247 	int mib[2];
248 	size_t size;
249 
250 	/* Re-read pages used for vnodes & executables */
251 	size = sizeof(uvmexp);
252 	mib[0] = CTL_VM;
253 	mib[1] = VM_UVMEXP2;
254 	if (sysctl(mib, 2, &uvmexp, &size, NULL, 0) < 0) {
255 		error("can't get uvmexp: %s\n", strerror(errno));
256 		memset(&uvmexp, 0, sizeof(uvmexp));
257 	}
258 }
259 
260 void
261 fetchbufcache(void)
262 {
263 	int count;
264 	struct buf_sysctl *bp, *buffers;
265 	struct vnode *vn;
266 	struct mount *mt;
267 	struct ml_entry *ml;
268 	int mib[6];
269 	size_t size;
270 	int extraslop = 0;
271 
272 	/* Re-read pages used for vnodes & executables */
273 	fetchuvmexp();
274 
275 	/* Initialise vnode cache and mount list. */
276 	vc_init();
277 	ml_init();
278 
279 	/* Get metadata buffers */
280 	size = 0;
281 	buffers = NULL;
282 	mib[0] = CTL_KERN;
283 	mib[1] = KERN_BUF;
284 	mib[2] = KERN_BUF_ALL;
285 	mib[3] = KERN_BUF_ALL;
286 	mib[4] = (int)sizeof(struct buf_sysctl);
287 	mib[5] = INT_MAX; /* we want them all */
288 again:
289 	if (sysctl(mib, 6, NULL, &size, NULL, 0) < 0) {
290 		error("can't get buffers size: %s\n", strerror(errno));
291 		return;
292 	}
293 	if (size == 0)
294 		return;
295 
296 	size += extraslop * sizeof(struct buf_sysctl);
297 	buffers = malloc(size);
298 	if (buffers == NULL) {
299 		error("can't allocate buffers: %s\n", strerror(errno));
300 		return;
301 	}
302 	if (sysctl(mib, 6, buffers, &size, NULL, 0) < 0) {
303 		free(buffers);
304 		if (extraslop == 0) {
305 			extraslop = 100;
306 			goto again;
307 		}
308 		error("can't get buffers: %s\n", strerror(errno));
309 		return;
310 	}
311 
312 	nbuf = size / sizeof(struct buf_sysctl);
313 	for (bp = buffers; bp < buffers + nbuf; bp++) {
314 		if (UINT64TOPTR(bp->b_vp) != NULL) {
315 			struct mount *mp;
316 			vn = vc_lookup(UINT64TOPTR(bp->b_vp));
317 			if (vn == NULL)
318 				break;
319 
320 			mp = vn->v_mount;
321 			/*
322 			 * References to mounted-on vnodes should be
323 			 * counted towards the mounted filesystem.
324 			 */
325 			if (vn->v_type == VBLK && vn->v_specinfo != NULL) {
326 				struct specinfo sp;
327 				if (!KREAD(vn->v_specinfo, &sp, sizeof(sp)))
328 					continue;
329 				if (sp.si_mountpoint)
330 					mp = sp.si_mountpoint;
331 			}
332 			if (mp != NULL)
333 				mt = ml_lookup(mp,
334 				    bp->b_bufsize,
335 				    bp->b_bcount);
336 		}
337 	}
338 
339 	/* simple sort - there's not that many entries */
340 	do {
341 		if ((ml = LIST_FIRST(&mount_list)) == NULL ||
342 		    LIST_NEXT(ml, ml_entries) == NULL)
343 			break;
344 
345 		count = 0;
346 		for (ml = LIST_FIRST(&mount_list); ml != NULL;
347 		    ml = LIST_NEXT(ml, ml_entries)) {
348 			if (LIST_NEXT(ml, ml_entries) == NULL)
349 				break;
350 			if (ml->ml_count < LIST_NEXT(ml, ml_entries)->ml_count) {
351 				ml = LIST_NEXT(ml, ml_entries);
352 				LIST_REMOVE(ml, ml_entries);
353 				LIST_INSERT_HEAD(&mount_list, ml, ml_entries);
354 				count++;
355 			}
356 		}
357 	} while (count != 0);
358 
359 	free(buffers);
360 }
361 
362 static void
363 vc_init(void)
364 {
365 	int i;
366 
367 	/* vc_addr == NULL for unused cache entry. */
368 	for (i = 0; i < VCACHE_SIZE; i++)
369 		vcache[i].vc_addr = NULL;
370 }
371 
372 static void
373 ml_init(void)
374 {
375 	struct ml_entry *ml;
376 
377 	/* Throw out the current mount list and start again. */
378 	while ((ml = LIST_FIRST(&mount_list)) != NULL) {
379 		LIST_REMOVE(ml, ml_entries);
380 		free(ml);
381 	}
382 }
383 
384 
385 static struct vnode *
386 vc_lookup(struct vnode *vaddr)
387 {
388 	struct vnode *ret;
389 	size_t i, oldest;
390 
391 	ret = NULL;
392 	oldest = 0;
393 	for (i = 0; i < VCACHE_SIZE; i++) {
394 		if (vcache[i].vc_addr == NULL)
395 			break;
396 		vcache[i].vc_age++;
397 		if (vcache[i].vc_age < vcache[oldest].vc_age)
398 			oldest = i;
399 		if (vcache[i].vc_addr == vaddr) {
400 			vcache[i].vc_age = 0;
401 			ret = &vcache[i].vc_node;
402 		}
403 	}
404 
405 	/* Find an entry in the cache? */
406 	if (ret != NULL)
407 		return(ret);
408 
409 	/* Go past the end of the cache? */
410 	if  (i >= VCACHE_SIZE)
411 		i = oldest;
412 
413 	/* Read in new vnode and reset age counter. */
414 	if (KREAD(vaddr, &vcache[i].vc_node, sizeof(struct vnode)) == 0)
415 		return NULL;
416 	vcache[i].vc_addr = vaddr;
417 	vcache[i].vc_age = 0;
418 
419 	return(&vcache[i].vc_node);
420 }
421 
422 static struct mount *
423 ml_lookup(struct mount *maddr, int size, int valid)
424 {
425 	struct ml_entry *ml;
426 
427 	for (ml = LIST_FIRST(&mount_list); ml != NULL;
428 	    ml = LIST_NEXT(ml, ml_entries))
429 		if (ml->ml_addr == maddr) {
430 			ml->ml_count++;
431 			ml->ml_size += size;
432 			ml->ml_valid += valid;
433 			if (ml->ml_addr == NULL)
434 				return(NULL);
435 			else
436 				return(&ml->ml_mount);
437 		}
438 
439 	if ((ml = malloc(sizeof(struct ml_entry))) == NULL) {
440 		error("out of memory");
441 		die(0);
442 	}
443 	LIST_INSERT_HEAD(&mount_list, ml, ml_entries);
444 	ml->ml_count = 1;
445 	ml->ml_size = size;
446 	ml->ml_valid = valid;
447 	ml->ml_addr = maddr;
448 	if (maddr == NULL)
449 		return(NULL);
450 
451 	KREAD(maddr, &ml->ml_mount, sizeof(struct mount));
452 	return(&ml->ml_mount);
453 }
454