xref: /netbsd-src/usr.bin/systat/bufcache.c (revision 5e4c038a45edbc7d63b7c2daa76e29f88b64a4e3)
1 /*	$NetBSD: bufcache.c,v 1.12 2001/12/09 03:07:58 chs 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 1.12 2001/12/09 03:07:58 chs 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 <kvm.h>
55 #include <math.h>
56 #include <nlist.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <unistd.h>
60 
61 #include "systat.h"
62 #include "extern.h"
63 
64 /*
65  * Definitions for the buffer free lists (from sys/kern/vfs_bio.c).
66  */
67 #define	BQUEUES		4		/* number of free buffer queues */
68 
69 #define	BQ_LOCKED	0		/* super-blocks &c */
70 #define	BQ_LRU		1		/* lru, useful buffers */
71 #define	BQ_AGE		2		/* rubbish */
72 #define	BQ_EMPTY	3		/* buffer headers with no memory */
73 
74 #define VCACHE_SIZE	50
75 
76 struct vcache {
77 	int vc_age;
78 	struct vnode *vc_addr;
79 	struct vnode vc_node;
80 };
81 
82 struct ml_entry {
83 	int ml_count;
84 	long ml_size;
85 	long ml_valid;
86 	struct mount *ml_addr;
87 	struct mount ml_mount;
88 	LIST_ENTRY(ml_entry) ml_entries;
89 };
90 
91 static struct nlist namelist[] = {
92 #define	X_NBUF		0
93 	{ "_nbuf" },
94 #define	X_BUF		1
95 	{ "_buf" },
96 #define	X_BUFQUEUES	2
97 	{ "_bufqueues" },
98 #define	X_BUFPAGES	3
99 	{ "_bufpages" },
100 	{ "" },
101 };
102 
103 static struct vcache vcache[VCACHE_SIZE];
104 static LIST_HEAD(mount_list, ml_entry) mount_list;
105 
106 static int nbuf, bufpages, bufkb, pgwidth, kbwidth;
107 static struct uvmexp_sysctl uvmexp;
108 static void *bufaddr;
109 static struct buf *buf = NULL;
110 static TAILQ_HEAD(bqueues, buf) bufqueues[BQUEUES];
111 
112 static void	vc_init(void);
113 static void	ml_init(void);
114 static struct 	vnode *vc_lookup(struct vnode *);
115 static struct 	mount *ml_lookup(struct mount *, int, int);
116 static void	fetchuvmexp(void);
117 
118 
119 WINDOW *
120 openbufcache(void)
121 {
122 
123 	return (subwin(stdscr, LINES-5-1, 0, 5, 0));
124 }
125 
126 void
127 closebufcache(WINDOW *w)
128 {
129 
130 	if (w == NULL)
131 		return;
132 	wclear(w);
133 	wrefresh(w);
134 	delwin(w);
135 	ml_init();		/* Clear out mount list */
136 }
137 
138 void
139 labelbufcache(void)
140 {
141 	mvwprintw(wnd, 0, 0,
142 	    "There are %*d metadata buffers using           %*d kBytes of memory.",
143 	    pgwidth, nbuf, kbwidth, bufkb);
144 	wclrtoeol(wnd);
145 	wmove(wnd, 1, 0);
146 	wclrtoeol(wnd);
147 	wmove(wnd, 2, 0);
148 	wclrtoeol(wnd);
149 	wmove(wnd, 3, 0);
150 	wclrtoeol(wnd);
151 	mvwaddstr(wnd, 4, 0,
152 "File System          Bufs used   %   kB in use   %  Bufsize kB   %  Util %");
153 	wclrtoeol(wnd);
154 }
155 
156 void
157 showbufcache(void)
158 {
159 	int tbuf, i, lastrow;
160 	long tvalid, tsize;
161 	struct ml_entry *ml;
162 
163 	mvwprintw(wnd, 1, 0,
164 	    "There are %*llu pages for cached file data using %*llu kBytes of memory.",
165 	    pgwidth, (long long)uvmexp.filepages,
166 	    kbwidth, (long long) uvmexp.filepages * getpagesize() / 1024);
167 	wclrtoeol(wnd);
168 	mvwprintw(wnd, 2, 0,
169 	    "There are %*llu pages for executables using      %*llu kBytes of memory.",
170 	    pgwidth, (long long)uvmexp.execpages,
171 	    kbwidth, (long long) uvmexp.execpages * getpagesize() / 1024);
172 	wclrtoeol(wnd);
173 
174 	tbuf = tvalid = tsize = 0;
175 	lastrow = 5;	/* Leave room for header. */
176 	for (i = lastrow, ml = LIST_FIRST(&mount_list); ml != NULL;
177 	    i++, ml = LIST_NEXT(ml, ml_entries)) {
178 
179 		/* Display in window if enough room. */
180 		if (i < getmaxy(wnd) - 2) {
181 			mvwprintw(wnd, i, 0, "%-20.20s", ml->ml_addr == NULL ?
182 			    "NULL" : ml->ml_mount.mnt_stat.f_mntonname);
183 			wprintw(wnd,
184 			    "    %6d %3d    %8ld %3ld    %8ld %3ld     %3ld",
185 			    ml->ml_count, (100 * ml->ml_count) / nbuf,
186 			    ml->ml_valid, (100 * ml->ml_valid) / bufkb,
187 			    ml->ml_size, (100 * ml->ml_size) / bufkb,
188 			    (100 * ml->ml_valid) / ml->ml_size);
189 			wclrtoeol(wnd);
190 			lastrow = i;
191 		}
192 
193 		/* Update statistics. */
194 		tbuf += ml->ml_count;
195 		tvalid += ml->ml_valid;
196 		tsize += ml->ml_size;
197 	}
198 
199 	wclrtobot(wnd);
200 	mvwprintw(wnd, lastrow + 2, 0,
201 	    "%-20s    %6d %3d    %8ld %3ld    %8ld %3ld     %3ld",
202 	    "Total:", tbuf, (100 * tbuf) / nbuf,
203 	    tvalid, (100 * tvalid) / bufkb,
204 	    tsize, (100 * tsize) / bufkb, (100 * tvalid) / tsize);
205 }
206 
207 int
208 initbufcache(void)
209 {
210 	if (namelist[X_NBUF].n_type == 0) {
211 		if (kvm_nlist(kd, namelist)) {
212 			nlisterr(namelist);
213 			return(0);
214 		}
215 		if (namelist[X_NBUF].n_type == 0) {
216 			error("No namelist");
217 			return(0);
218 		}
219 	}
220 
221 	NREAD(X_NBUF, &nbuf, sizeof(nbuf));
222 	NREAD(X_BUFPAGES, &bufpages, sizeof(bufpages));
223 	bufkb = bufpages * sysconf(_SC_PAGESIZE) / 1024;
224 
225 	if ((buf = malloc(nbuf * sizeof(struct buf))) == NULL) {
226 		error("malloc failed");
227 		die(0);
228 	}
229 	NREAD(X_BUF, &bufaddr, sizeof(bufaddr));
230 
231 	fetchuvmexp();
232 	pgwidth = (int)(floor(log10((double)uvmexp.npages)) + 1);
233 	kbwidth = (int)(floor(log10(uvmexp.npages * getpagesize() / 1024.0)) + 1);
234 
235 	return(1);
236 }
237 
238 static void
239 fetchuvmexp(void)
240 {
241 	int mib[2];
242 	size_t size;
243 
244 	/* Re-read pages used for vnodes & executables */
245 	size = sizeof(uvmexp);
246 	mib[0] = CTL_VM;
247 	mib[1] = VM_UVMEXP2;
248 	if (sysctl(mib, 2, &uvmexp, &size, NULL, 0) < 0) {
249 		error("can't get uvmexp: %s\n", strerror(errno));
250 		memset(&uvmexp, 0, sizeof(uvmexp));
251 	}
252 }
253 
254 void
255 fetchbufcache(void)
256 {
257 	int i, count;
258 	struct buf *bp;
259 	struct vnode *vn;
260 	struct mount *mt;
261 	struct ml_entry *ml;
262 
263 	fetchuvmexp();
264 	/* Re-read bufqueues lists and buffer cache headers */
265 	NREAD(X_BUFQUEUES, bufqueues, sizeof(bufqueues));
266 	KREAD(bufaddr, buf, sizeof(struct buf) * nbuf);
267 
268 	/* Initialise vnode cache and mount list. */
269 	vc_init();
270 	ml_init();
271 	for (i = 0; i < BQUEUES; i++) {
272 		for (bp = bufqueues[i].tqh_first; bp != NULL;
273 		    bp = bp->b_freelist.tqe_next) {
274 			if (bp != NULL) {
275 				bp = (struct buf *)((u_long)bp + (u_long)buf -
276 				    (u_long)bufaddr);
277 
278 				if (bp->b_vp != NULL) {
279 					vn = vc_lookup(bp->b_vp);
280 					if (vn == NULL)
281 						errx(1,
282 						    "vc_lookup returns NULL!\n");
283 					if (vn->v_mount != NULL)
284 						mt = ml_lookup(vn->v_mount,
285 						    bp->b_bufsize,
286 						    bp->b_bcount);
287 				}
288 			}
289 		}
290 	}
291 
292 	/* simple sort - there's not that many entries */
293 	do {
294 		if ((ml = LIST_FIRST(&mount_list)) == NULL ||
295 		    LIST_NEXT(ml, ml_entries) == NULL)
296 			break;
297 
298 		count = 0;
299 		for (ml = LIST_FIRST(&mount_list); ml != NULL;
300 		    ml = LIST_NEXT(ml, ml_entries)) {
301 			if (LIST_NEXT(ml, ml_entries) == NULL)
302 				break;
303 			if (ml->ml_count < LIST_NEXT(ml, ml_entries)->ml_count) {
304 				ml = LIST_NEXT(ml, ml_entries);
305 				LIST_REMOVE(ml, ml_entries);
306 				LIST_INSERT_HEAD(&mount_list, ml, ml_entries);
307 				count++;
308 			}
309 		}
310 	} while (count != 0);
311 }
312 
313 static void
314 vc_init(void)
315 {
316 	int i;
317 
318 	/* vc_addr == NULL for unused cache entry. */
319 	for (i = 0; i < VCACHE_SIZE; i++)
320 		vcache[i].vc_addr = NULL;
321 }
322 
323 static void
324 ml_init(void)
325 {
326 	struct ml_entry *ml;
327 
328 	/* Throw out the current mount list and start again. */
329 	while ((ml = LIST_FIRST(&mount_list)) != NULL) {
330 		LIST_REMOVE(ml, ml_entries);
331 		free(ml);
332 	}
333 }
334 
335 
336 static struct vnode *
337 vc_lookup(struct vnode *vaddr)
338 {
339 	struct vnode *ret;
340 	int i, oldest, match;
341 
342 	ret = NULL;
343 	oldest = match = 0;
344 	for (i = 0; i < VCACHE_SIZE || vcache[i].vc_addr == NULL; i++) {
345 		vcache[i].vc_age++;
346 		if (vcache[i].vc_addr == NULL)
347 			break;
348 		if (vcache[i].vc_age < vcache[oldest].vc_age)
349 			oldest = i;
350 		if (vcache[i].vc_addr == vaddr) {
351 			vcache[i].vc_age = 0;
352 			match = i;
353 			ret = &vcache[i].vc_node;
354 		}
355 	}
356 
357 	/* Find an entry in the cache? */
358 	if (ret != NULL)
359 		return(ret);
360 
361 	/* Go past the end of the cache? */
362 	if  (i >= VCACHE_SIZE)
363 		i = oldest;
364 
365 	/* Read in new vnode and reset age counter. */
366 	KREAD(vaddr, &vcache[i].vc_node, sizeof(struct vnode));
367 	vcache[i].vc_addr = vaddr;
368 	vcache[i].vc_age = 0;
369 
370 	return(&vcache[i].vc_node);
371 }
372 
373 static struct mount *
374 ml_lookup(struct mount *maddr, int size, int valid)
375 {
376 	struct ml_entry *ml;
377 
378 	for (ml = LIST_FIRST(&mount_list); ml != NULL;
379 	    ml = LIST_NEXT(ml, ml_entries))
380 		if (ml->ml_addr == maddr) {
381 			ml->ml_count++;
382 			ml->ml_size += size / 1024;
383 			ml->ml_valid += valid / 1024;
384 			if (ml->ml_addr == NULL)
385 				return(NULL);
386 			else
387 				return(&ml->ml_mount);
388 		}
389 
390 	if ((ml = malloc(sizeof(struct ml_entry))) == NULL) {
391 		error("out of memory");
392 		die(0);
393 	}
394 	LIST_INSERT_HEAD(&mount_list, ml, ml_entries);
395 	ml->ml_count = 1;
396 	ml->ml_size = size / 1024;
397 	ml->ml_valid = valid / 1024;
398 	ml->ml_addr = maddr;
399 	if (maddr == NULL)
400 		return(NULL);
401 
402 	KREAD(maddr, &ml->ml_mount, sizeof(struct mount));
403 	return(&ml->ml_mount);
404 }
405