xref: /netbsd-src/usr.bin/systat/bufcache.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /*	$NetBSD: bufcache.c,v 1.26 2013/10/18 20:47:07 christos 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 1.26 2013/10/18 20:47:07 christos 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 vcache vcache[VCACHE_SIZE];
78 static LIST_HEAD(mount_list, ml_entry) mount_list;
79 
80 static uint64_t bufmem;
81 static u_int nbuf, pgwidth, kbwidth;
82 static struct uvmexp_sysctl uvmexp;
83 
84 static void	vc_init(void);
85 static void	ml_init(void);
86 static struct 	vnode *vc_lookup(struct vnode *);
87 static struct 	mount *ml_lookup(struct mount *, int, int);
88 static void	fetchuvmexp(void);
89 
90 
91 WINDOW *
92 openbufcache(void)
93 {
94 
95 	return (subwin(stdscr, -1, 0, 5, 0));
96 }
97 
98 void
99 closebufcache(WINDOW *w)
100 {
101 
102 	if (w == NULL)
103 		return;
104 	wclear(w);
105 	wrefresh(w);
106 	delwin(w);
107 	ml_init();		/* Clear out mount list */
108 }
109 
110 void
111 labelbufcache(void)
112 {
113 	int i;
114 
115 	for (i = 0; i <= PAGEINFO_ROWS; i++) {
116 		wmove(wnd, i, 0);
117 		wclrtoeol(wnd);
118 	}
119 	mvwaddstr(wnd, PAGEINFO_ROWS + 1, 0, "File System          Bufs used"
120 	    "   %   kB in use   %  Bufsize kB   %  Util %");
121 	wclrtoeol(wnd);
122 }
123 
124 void
125 showbufcache(void)
126 {
127 	int tbuf, i, lastrow;
128 	double tvalid, tsize;
129 	struct ml_entry *ml;
130 	size_t len;
131 
132 	len = sizeof(bufmem);
133 	if (sysctlbyname("vm.bufmem", &bufmem, &len, NULL, 0))
134 		error("can't get \"vm.bufmmem\": %s", strerror(errno));
135 
136 	mvwprintw(wnd, 0, 0,
137 	    "   %*d metadata buffers using             %*"PRIu64" kBytes of "
138 	    "memory (%2.0f%%).",
139 	    pgwidth, nbuf, kbwidth, bufmem / 1024,
140 	    ((bufmem * 100.0) + 0.5) / getpagesize() / uvmexp.npages);
141 	wclrtoeol(wnd);
142 	mvwprintw(wnd, 1, 0,
143 	    "   %*" PRIu64 " pages for cached file data using   %*"
144 	    PRIu64 " kBytes of memory (%2.0f%%).",
145 	    pgwidth, uvmexp.filepages,
146 	    kbwidth, uvmexp.filepages * getpagesize() / 1024,
147 	    (uvmexp.filepages * 100 + 0.5) / uvmexp.npages);
148 	wclrtoeol(wnd);
149 	mvwprintw(wnd, 2, 0,
150 	    "   %*" PRIu64 " pages for executables using        %*"
151 	    PRIu64 " kBytes of memory (%2.0f%%).",
152 	    pgwidth, uvmexp.execpages,
153 	    kbwidth, uvmexp.execpages * getpagesize() / 1024,
154 	    (uvmexp.execpages * 100 + 0.5) / uvmexp.npages);
155 	wclrtoeol(wnd);
156 	mvwprintw(wnd, 3, 0,
157 	    "   %*" PRIu64 " pages for anon (non-file) data     %*"
158 	    PRIu64 " kBytes of memory (%2.0f%%).",
159 	    pgwidth, uvmexp.anonpages,
160 	    kbwidth, uvmexp.anonpages * getpagesize() / 1024,
161 	    (uvmexp.anonpages * 100 + 0.5) / uvmexp.npages);
162 	wclrtoeol(wnd);
163 	mvwprintw(wnd, 4, 0,
164 	    "   %*" PRIu64 " free pages                         %*"
165 	    PRIu64 " kBytes of memory (%2.0f%%).",
166 	    pgwidth, uvmexp.free,
167 	    kbwidth, uvmexp.free * getpagesize() / 1024,
168 	    (uvmexp.free * 100 + 0.5) / uvmexp.npages);
169 	wclrtoeol(wnd);
170 
171 	if (nbuf == 0 || bufmem == 0) {
172 		wclrtobot(wnd);
173 		return;
174 	}
175 
176 	tbuf = 0;
177 	tvalid = tsize = 0;
178 	lastrow = PAGEINFO_ROWS + 2;	/* Leave room for header. */
179 	for (i = lastrow, ml = LIST_FIRST(&mount_list); ml != NULL;
180 	    i++, ml = LIST_NEXT(ml, ml_entries)) {
181 
182 		int cnt = ml->ml_count;
183 		double v = ml->ml_valid;
184 		double s = ml->ml_size;
185 
186 		/* Display in window if enough room. */
187 		if (i < getmaxy(wnd) - 2) {
188 			mvwprintw(wnd, i, 0, "%-20.20s", ml->ml_addr == NULL ?
189 			    "NULL" : ml->ml_mount.mnt_stat.f_mntonname);
190 			wprintw(wnd,
191 			    "    %6d %3d    %8ld %3.0f    %8ld %3.0f     %3.0f",
192 			    cnt, (100 * cnt) / nbuf,
193 			    (long)(v/1024), 100 * v / bufmem,
194 			    (long)(s/1024), 100 * s / bufmem,
195 			    100 * v / s);
196 			wclrtoeol(wnd);
197 			lastrow = i;
198 		}
199 
200 		/* Update statistics. */
201 		tbuf += cnt;
202 		tvalid += v;
203 		tsize += s;
204 	}
205 
206 	wclrtobot(wnd);
207 	mvwprintw(wnd, lastrow + 2, 0,
208 	    "%-20s    %6d %3d    %8ld %3.0f    %8ld %3.0f     %3.0f",
209 	    "Total:", tbuf, (100 * tbuf) / nbuf,
210 	    (long)(tvalid/1024), 100 * tvalid / bufmem,
211 	    (long)(tsize/1024), 100 * tsize / bufmem,
212 	    tsize != 0 ? ((100 * tvalid) / tsize) : 0);
213 }
214 
215 int
216 initbufcache(void)
217 {
218 	fetchuvmexp();
219 	pgwidth = (int)(floor(log10((double)uvmexp.npages)) + 1);
220 	kbwidth = (int)(floor(log10(uvmexp.npages * getpagesize() / 1024.0)) +
221 	    1);
222 
223 	return(1);
224 }
225 
226 static void
227 fetchuvmexp(void)
228 {
229 	int mib[2];
230 	size_t size;
231 
232 	/* Re-read pages used for vnodes & executables */
233 	size = sizeof(uvmexp);
234 	mib[0] = CTL_VM;
235 	mib[1] = VM_UVMEXP2;
236 	if (sysctl(mib, 2, &uvmexp, &size, NULL, 0) < 0) {
237 		error("can't get uvmexp: %s\n", strerror(errno));
238 		memset(&uvmexp, 0, sizeof(uvmexp));
239 	}
240 }
241 
242 void
243 fetchbufcache(void)
244 {
245 	int count;
246 	struct buf_sysctl *bp, *buffers;
247 	struct vnode *vn;
248 	struct ml_entry *ml;
249 	int mib[6];
250 	size_t size;
251 	int extraslop = 0;
252 
253 	/* Re-read pages used for vnodes & executables */
254 	fetchuvmexp();
255 
256 	/* Initialise vnode cache and mount list. */
257 	vc_init();
258 	ml_init();
259 
260 	/* Get metadata buffers */
261 	size = 0;
262 	buffers = NULL;
263 	mib[0] = CTL_KERN;
264 	mib[1] = KERN_BUF;
265 	mib[2] = KERN_BUF_ALL;
266 	mib[3] = KERN_BUF_ALL;
267 	mib[4] = (int)sizeof(struct buf_sysctl);
268 	mib[5] = INT_MAX; /* we want them all */
269 again:
270 	if (sysctl(mib, 6, NULL, &size, NULL, 0) < 0) {
271 		error("can't get buffers size: %s\n", strerror(errno));
272 		return;
273 	}
274 	if (size == 0)
275 		return;
276 
277 	size += extraslop * sizeof(struct buf_sysctl);
278 	buffers = malloc(size);
279 	if (buffers == NULL) {
280 		error("can't allocate buffers: %s\n", strerror(errno));
281 		return;
282 	}
283 	if (sysctl(mib, 6, buffers, &size, NULL, 0) < 0) {
284 		free(buffers);
285 		if (extraslop == 0) {
286 			extraslop = 100;
287 			goto again;
288 		}
289 		error("can't get buffers: %s\n", strerror(errno));
290 		return;
291 	}
292 
293 	nbuf = size / sizeof(struct buf_sysctl);
294 	for (bp = buffers; bp < buffers + nbuf; bp++) {
295 		if (UINT64TOPTR(bp->b_vp) != NULL) {
296 			struct mount *mp;
297 			vn = vc_lookup(UINT64TOPTR(bp->b_vp));
298 			if (vn == NULL)
299 				break;
300 
301 			mp = vn->v_mount;
302 			/*
303 			 * References to mounted-on vnodes should be
304 			 * counted towards the mounted filesystem.
305 			 */
306 			if (vn->v_type == VBLK && vn->v_specnode != NULL) {
307 				specnode_t sn;
308 				specdev_t sd;
309 				if (!KREAD(vn->v_specnode, &sn, sizeof(sn)))
310 					continue;
311 				if (!KREAD(sn.sn_dev, &sd, sizeof(sd)))
312 					continue;
313 				if (sd.sd_mountpoint)
314 					mp = sd.sd_mountpoint;
315 			}
316 			if (mp != NULL)
317 				(void)ml_lookup(mp, bp->b_bufsize,
318 				    bp->b_bcount);
319 		}
320 	}
321 
322 	/* simple sort - there's not that many entries */
323 	do {
324 		if ((ml = LIST_FIRST(&mount_list)) == NULL ||
325 		    LIST_NEXT(ml, ml_entries) == NULL)
326 			break;
327 
328 		count = 0;
329 		for (ml = LIST_FIRST(&mount_list); ml != NULL;
330 		    ml = LIST_NEXT(ml, ml_entries)) {
331 			if (LIST_NEXT(ml, ml_entries) == NULL)
332 				break;
333 			if (ml->ml_count < LIST_NEXT(ml, ml_entries)->ml_count) {
334 				ml = LIST_NEXT(ml, ml_entries);
335 				LIST_REMOVE(ml, ml_entries);
336 				LIST_INSERT_HEAD(&mount_list, ml, ml_entries);
337 				count++;
338 			}
339 		}
340 	} while (count != 0);
341 
342 	free(buffers);
343 }
344 
345 static void
346 vc_init(void)
347 {
348 	int i;
349 
350 	/* vc_addr == NULL for unused cache entry. */
351 	for (i = 0; i < VCACHE_SIZE; i++)
352 		vcache[i].vc_addr = NULL;
353 }
354 
355 static void
356 ml_init(void)
357 {
358 	struct ml_entry *ml;
359 
360 	/* Throw out the current mount list and start again. */
361 	while ((ml = LIST_FIRST(&mount_list)) != NULL) {
362 		LIST_REMOVE(ml, ml_entries);
363 		free(ml);
364 	}
365 }
366 
367 
368 static struct vnode *
369 vc_lookup(struct vnode *vaddr)
370 {
371 	struct vnode *ret;
372 	size_t i, oldest;
373 
374 	ret = NULL;
375 	oldest = 0;
376 	for (i = 0; i < VCACHE_SIZE; i++) {
377 		if (vcache[i].vc_addr == NULL)
378 			break;
379 		vcache[i].vc_age++;
380 		if (vcache[i].vc_age < vcache[oldest].vc_age)
381 			oldest = i;
382 		if (vcache[i].vc_addr == vaddr) {
383 			vcache[i].vc_age = 0;
384 			ret = &vcache[i].vc_node;
385 		}
386 	}
387 
388 	/* Find an entry in the cache? */
389 	if (ret != NULL)
390 		return(ret);
391 
392 	/* Go past the end of the cache? */
393 	if  (i >= VCACHE_SIZE)
394 		i = oldest;
395 
396 	/* Read in new vnode and reset age counter. */
397 	if (KREAD(vaddr, &vcache[i].vc_node, sizeof(struct vnode)) == 0)
398 		return NULL;
399 	vcache[i].vc_addr = vaddr;
400 	vcache[i].vc_age = 0;
401 
402 	return(&vcache[i].vc_node);
403 }
404 
405 static struct mount *
406 ml_lookup(struct mount *maddr, int size, int valid)
407 {
408 	struct ml_entry *ml;
409 
410 	for (ml = LIST_FIRST(&mount_list); ml != NULL;
411 	    ml = LIST_NEXT(ml, ml_entries))
412 		if (ml->ml_addr == maddr) {
413 			ml->ml_count++;
414 			ml->ml_size += size;
415 			ml->ml_valid += valid;
416 			if (ml->ml_addr == NULL)
417 				return(NULL);
418 			else
419 				return(&ml->ml_mount);
420 		}
421 
422 	if ((ml = malloc(sizeof(struct ml_entry))) == NULL) {
423 		error("out of memory");
424 		die(0);
425 	}
426 	LIST_INSERT_HEAD(&mount_list, ml, ml_entries);
427 	ml->ml_count = 1;
428 	ml->ml_size = size;
429 	ml->ml_valid = valid;
430 	ml->ml_addr = maddr;
431 	if (maddr == NULL)
432 		return(NULL);
433 
434 	KREAD(maddr, &ml->ml_mount, sizeof(struct mount));
435 	return(&ml->ml_mount);
436 }
437