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bcache.c (136097) bcache.c (298230)
1/*-
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
1/*-
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3 * Copyright 2015 Toomas Soome <tsoome@me.com>
3 * 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

--- 9 unchanged lines hidden (view full) ---

20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright

--- 9 unchanged lines hidden (view full) ---

21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/boot/common/bcache.c 136097 2004-10-03 16:34:01Z stefanf $");
29#include <sys/param.h>
30__FBSDID("$FreeBSD: head/sys/boot/common/bcache.c 298230 2016-04-18 23:09:22Z allanjude $");
29
30/*
31
32/*
31 * Simple LRU block cache
33 * Simple hashed block cache
32 */
33
34#include <sys/stdint.h>
35
36#include <stand.h>
37#include <string.h>
34 */
35
36#include <sys/stdint.h>
37
38#include <stand.h>
39#include <string.h>
38#include <bitstring.h>
40#include <strings.h>
39
40#include "bootstrap.h"
41
42/* #define BCACHE_DEBUG */
43
44#ifdef BCACHE_DEBUG
41
42#include "bootstrap.h"
43
44/* #define BCACHE_DEBUG */
45
46#ifdef BCACHE_DEBUG
45#define BCACHE_TIMEOUT 10
46# define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args)
47#else
47# define DEBUG(fmt, args...) printf("%s: " fmt "\n" , __func__ , ## args)
48#else
48#define BCACHE_TIMEOUT 2
49# define DEBUG(fmt, args...)
50#endif
51
49# define DEBUG(fmt, args...)
50#endif
51
52
53struct bcachectl
54{
55 daddr_t bc_blkno;
52struct bcachectl
53{
54 daddr_t bc_blkno;
56 time_t bc_stamp;
57 int bc_count;
58};
59
55 int bc_count;
56};
57
60static struct bcachectl *bcache_ctl;
61static caddr_t bcache_data;
62static bitstr_t *bcache_miss;
63static u_int bcache_nblks;
64static u_int bcache_blksize;
65static u_int bcache_hits, bcache_misses, bcache_ops, bcache_bypasses;
66static u_int bcache_flushes;
67static u_int bcache_bcount;
58/*
59 * bcache per device node. cache is allocated on device first open and freed
60 * on last close, to save memory. The issue there is the size; biosdisk
61 * supports up to 31 (0x1f) devices. Classic setup would use single disk
62 * to boot from, but this has changed with zfs.
63 */
64struct bcache {
65 struct bcachectl *bcache_ctl;
66 caddr_t bcache_data;
67 u_int bcache_nblks;
68 size_t ra;
69};
68
70
69static void bcache_invalidate(daddr_t blkno);
70static void bcache_insert(caddr_t buf, daddr_t blkno);
71static int bcache_lookup(caddr_t buf, daddr_t blkno);
71static u_int bcache_total_nblks; /* set by bcache_init */
72static u_int bcache_blksize; /* set by bcache_init */
73static u_int bcache_numdev; /* set by bcache_add_dev */
74/* statistics */
75static u_int bcache_units; /* number of devices with cache */
76static u_int bcache_unit_nblks; /* nblocks per unit */
77static u_int bcache_hits;
78static u_int bcache_misses;
79static u_int bcache_ops;
80static u_int bcache_bypasses;
81static u_int bcache_bcount;
82static u_int bcache_rablks;
72
83
84#define BHASH(bc, blkno) ((blkno) & ((bc)->bcache_nblks - 1))
85#define BCACHE_LOOKUP(bc, blkno) \
86 ((bc)->bcache_ctl[BHASH((bc), (blkno))].bc_blkno != (blkno))
87#define BCACHE_READAHEAD 256
88#define BCACHE_MINREADAHEAD 32
89
90static void bcache_invalidate(struct bcache *bc, daddr_t blkno);
91static void bcache_insert(struct bcache *bc, daddr_t blkno);
92static void bcache_free_instance(struct bcache *bc);
93
73/*
74 * Initialise the cache for (nblks) of (bsize).
75 */
94/*
95 * Initialise the cache for (nblks) of (bsize).
96 */
76int
97void
77bcache_init(u_int nblks, size_t bsize)
78{
98bcache_init(u_int nblks, size_t bsize)
99{
79 /* discard any old contents */
80 if (bcache_data != NULL) {
81 free(bcache_data);
82 bcache_data = NULL;
83 free(bcache_ctl);
84 }
85
86 /* Allocate control structures */
87 bcache_nblks = nblks;
100 /* set up control data */
101 bcache_total_nblks = nblks;
88 bcache_blksize = bsize;
102 bcache_blksize = bsize;
89 bcache_data = malloc(bcache_nblks * bcache_blksize);
90 bcache_ctl = (struct bcachectl *)malloc(bcache_nblks * sizeof(struct bcachectl));
91 bcache_miss = bit_alloc((bcache_nblks + 1) / 2);
92 if ((bcache_data == NULL) || (bcache_ctl == NULL) || (bcache_miss == NULL)) {
93 if (bcache_miss)
94 free(bcache_miss);
95 if (bcache_ctl)
96 free(bcache_ctl);
97 if (bcache_data)
98 free(bcache_data);
99 bcache_data = NULL;
100 return(ENOMEM);
101 }
102
103 return(0);
104}
105
106/*
103}
104
105/*
107 * Flush the cache
106 * add number of devices to bcache. we have to divide cache space
107 * between the devices, so bcache_add_dev() can be used to set up the
108 * number. The issue is, we need to get the number before actual allocations.
109 * bcache_add_dev() is supposed to be called from device init() call, so the
110 * assumption is, devsw dv_init is called for plain devices first, and
111 * for zfs, last.
108 */
109void
112 */
113void
110bcache_flush(void)
114bcache_add_dev(int devices)
111{
115{
112 u_int i;
116 bcache_numdev += devices;
117}
113
118
114 bcache_flushes++;
119void *
120bcache_allocate(void)
121{
122 u_int i;
123 struct bcache *bc = malloc(sizeof (struct bcache));
124 int disks = bcache_numdev;
115
125
126 if (disks == 0)
127 disks = 1; /* safe guard */
128
129 if (bc == NULL) {
130 errno = ENOMEM;
131 return (bc);
132 }
133
134 /*
135 * the bcache block count must be power of 2 for hash function
136 */
137 i = fls(disks) - 1; /* highbit - 1 */
138 if (disks > (1 << i)) /* next power of 2 */
139 i++;
140
141 bc->bcache_nblks = bcache_total_nblks >> i;
142 bcache_unit_nblks = bc->bcache_nblks;
143 bc->bcache_data = malloc(bc->bcache_nblks * bcache_blksize);
144 if (bc->bcache_data == NULL) {
145 /* dont error out yet. fall back to 32 blocks and try again */
146 bc->bcache_nblks = 32;
147 bc->bcache_data = malloc(bc->bcache_nblks * bcache_blksize);
148 }
149
150 bc->bcache_ctl = malloc(bc->bcache_nblks * sizeof(struct bcachectl));
151
152 if ((bc->bcache_data == NULL) || (bc->bcache_ctl == NULL)) {
153 bcache_free_instance(bc);
154 errno = ENOMEM;
155 return(NULL);
156 }
157
116 /* Flush the cache */
158 /* Flush the cache */
117 for (i = 0; i < bcache_nblks; i++) {
118 bcache_ctl[i].bc_count = -1;
119 bcache_ctl[i].bc_blkno = -1;
159 for (i = 0; i < bc->bcache_nblks; i++) {
160 bc->bcache_ctl[i].bc_count = -1;
161 bc->bcache_ctl[i].bc_blkno = -1;
120 }
162 }
163 bcache_units++;
164 bc->ra = BCACHE_READAHEAD; /* optimistic read ahead */
165 return (bc);
121}
122
166}
167
168void
169bcache_free(void *cache)
170{
171 struct bcache *bc = cache;
172
173 if (bc == NULL)
174 return;
175
176 bcache_free_instance(bc);
177 bcache_units--;
178}
179
123/*
124 * Handle a write request; write directly to the disk, and populate the
125 * cache with the new values.
126 */
127static int
180/*
181 * Handle a write request; write directly to the disk, and populate the
182 * cache with the new values.
183 */
184static int
128write_strategy(void *devdata, int unit, int rw, daddr_t blk, size_t size,
129 char *buf, size_t *rsize)
185write_strategy(void *devdata, int rw, daddr_t blk, size_t offset,
186 size_t size, char *buf, size_t *rsize)
130{
131 struct bcache_devdata *dd = (struct bcache_devdata *)devdata;
187{
188 struct bcache_devdata *dd = (struct bcache_devdata *)devdata;
189 struct bcache *bc = dd->dv_cache;
132 daddr_t i, nblk;
190 daddr_t i, nblk;
133 int err;
134
135 nblk = size / bcache_blksize;
136
137 /* Invalidate the blocks being written */
138 for (i = 0; i < nblk; i++) {
191
192 nblk = size / bcache_blksize;
193
194 /* Invalidate the blocks being written */
195 for (i = 0; i < nblk; i++) {
139 bcache_invalidate(blk + i);
196 bcache_invalidate(bc, blk + i);
140 }
141
142 /* Write the blocks */
197 }
198
199 /* Write the blocks */
143 err = dd->dv_strategy(dd->dv_devdata, rw, blk, size, buf, rsize);
144
145 /* Populate the block cache with the new data */
146 if (err == 0) {
147 for (i = 0; i < nblk; i++) {
148 bcache_insert(buf + (i * bcache_blksize),blk + i);
149 }
150 }
151
152 return err;
200 return (dd->dv_strategy(dd->dv_devdata, rw, blk, offset, size, buf, rsize));
153}
154
155/*
156 * Handle a read request; fill in parts of the request that can
157 * be satisfied by the cache, use the supplied strategy routine to do
158 * device I/O and then use the I/O results to populate the cache.
159 */
160static int
201}
202
203/*
204 * Handle a read request; fill in parts of the request that can
205 * be satisfied by the cache, use the supplied strategy routine to do
206 * device I/O and then use the I/O results to populate the cache.
207 */
208static int
161read_strategy(void *devdata, int unit, int rw, daddr_t blk, size_t size,
162 char *buf, size_t *rsize)
209read_strategy(void *devdata, int rw, daddr_t blk, size_t offset,
210 size_t size, char *buf, size_t *rsize)
163{
164 struct bcache_devdata *dd = (struct bcache_devdata *)devdata;
211{
212 struct bcache_devdata *dd = (struct bcache_devdata *)devdata;
165 int p_size, result;
166 daddr_t p_blk, i, j, nblk;
213 struct bcache *bc = dd->dv_cache;
214 size_t i, nblk, p_size, r_size, complete, ra;
215 int result;
216 daddr_t p_blk;
167 caddr_t p_buf;
168
217 caddr_t p_buf;
218
219 if (bc == NULL) {
220 errno = ENODEV;
221 return (-1);
222 }
223
224 if (rsize != NULL)
225 *rsize = 0;
226
169 nblk = size / bcache_blksize;
227 nblk = size / bcache_blksize;
228 if ((nblk == 0 && size != 0) || offset != 0)
229 nblk++;
170 result = 0;
230 result = 0;
231 complete = 1;
171
232
172 /* Satisfy any cache hits up front */
233 /* Satisfy any cache hits up front, break on first miss */
173 for (i = 0; i < nblk; i++) {
234 for (i = 0; i < nblk; i++) {
174 if (bcache_lookup(buf + (bcache_blksize * i), blk + i)) {
175 bit_set(bcache_miss, i); /* cache miss */
176 bcache_misses++;
235 if (BCACHE_LOOKUP(bc, (daddr_t)(blk + i))) {
236 bcache_misses += (nblk - i);
237 complete = 0;
238 if (nblk - i > BCACHE_MINREADAHEAD && bc->ra > BCACHE_MINREADAHEAD)
239 bc->ra >>= 1; /* reduce read ahead */
240 break;
177 } else {
241 } else {
178 bit_clear(bcache_miss, i); /* cache hit */
179 bcache_hits++;
180 }
181 }
182
242 bcache_hits++;
243 }
244 }
245
183 /* Go back and fill in any misses XXX optimise */
184 p_blk = -1;
185 p_buf = NULL;
186 p_size = 0;
187 for (i = 0; i < nblk; i++) {
188 if (bit_test(bcache_miss, i)) {
189 /* miss, add to pending transfer */
190 if (p_blk == -1) {
191 p_blk = blk + i;
192 p_buf = buf + (bcache_blksize * i);
193 p_size = 1;
194 } else {
195 p_size++;
196 }
197 } else if (p_blk != -1) {
198 /* hit, complete pending transfer */
199 result = dd->dv_strategy(dd->dv_devdata, rw, p_blk, p_size * bcache_blksize, p_buf, NULL);
200 if (result != 0)
201 goto done;
202 for (j = 0; j < p_size; j++)
203 bcache_insert(p_buf + (j * bcache_blksize), p_blk + j);
204 p_blk = -1;
205 }
246 if (complete) { /* whole set was in cache, return it */
247 if (bc->ra < BCACHE_READAHEAD)
248 bc->ra <<= 1; /* increase read ahead */
249 bcopy(bc->bcache_data + (bcache_blksize * BHASH(bc, blk)) + offset,
250 buf, size);
251 goto done;
252 }
253
254 /*
255 * Fill in any misses. From check we have i pointing to first missing
256 * block, read in all remaining blocks + readahead.
257 * We have space at least for nblk - i before bcache wraps.
258 */
259 p_blk = blk + i;
260 p_buf = bc->bcache_data + (bcache_blksize * BHASH(bc, p_blk));
261 r_size = bc->bcache_nblks - BHASH(bc, p_blk); /* remaining blocks */
262
263 p_size = MIN(r_size, nblk - i); /* read at least those blocks */
264
265 ra = bc->bcache_nblks - BHASH(bc, p_blk + p_size);
266 if (ra != bc->bcache_nblks) { /* do we have RA space? */
267 ra = MIN(bc->ra, ra);
268 p_size += ra;
206 }
269 }
207 if (p_blk != -1) {
208 /* pending transfer left */
209 result = dd->dv_strategy(dd->dv_devdata, rw, p_blk, p_size * bcache_blksize, p_buf, NULL);
210 if (result != 0)
211 goto done;
212 for (j = 0; j < p_size; j++)
213 bcache_insert(p_buf + (j * bcache_blksize), p_blk + j);
270
271 /* invalidate bcache */
272 for (i = 0; i < p_size; i++) {
273 bcache_invalidate(bc, p_blk + i);
214 }
274 }
215
275 r_size = 0;
276 result = dd->dv_strategy(dd->dv_devdata, rw, p_blk, 0,
277 p_size * bcache_blksize, p_buf, &r_size);
278
279 if (result)
280 goto done;
281
282 r_size /= bcache_blksize;
283 for (i = 0; i < r_size; i++)
284 bcache_insert(bc, p_blk + i);
285
286 bcache_rablks += ra;
287 bcopy(bc->bcache_data + (bcache_blksize * BHASH(bc, blk)) + offset, buf,
288 size);
289
216 done:
217 if ((result == 0) && (rsize != NULL))
218 *rsize = size;
219 return(result);
220}
221
222/*
290 done:
291 if ((result == 0) && (rsize != NULL))
292 *rsize = size;
293 return(result);
294}
295
296/*
223 * Requests larger than 1/2 the cache size will be bypassed and go
297 * Requests larger than 1/2 cache size will be bypassed and go
224 * directly to the disk. XXX tune this.
225 */
226int
298 * directly to the disk. XXX tune this.
299 */
300int
227bcache_strategy(void *devdata, int unit, int rw, daddr_t blk, size_t size,
228 char *buf, size_t *rsize)
301bcache_strategy(void *devdata, int rw, daddr_t blk, size_t offset,
302 size_t size, char *buf, size_t *rsize)
229{
303{
230 static int bcache_unit = -1;
231 struct bcache_devdata *dd = (struct bcache_devdata *)devdata;
304 struct bcache_devdata *dd = (struct bcache_devdata *)devdata;
305 struct bcache *bc = dd->dv_cache;
306 u_int bcache_nblks = 0;
307 int nblk, cblk, ret;
308 size_t csize, isize, total;
232
233 bcache_ops++;
234
309
310 bcache_ops++;
311
235 if(bcache_unit != unit) {
236 bcache_flush();
237 bcache_unit = unit;
238 }
312 if (bc != NULL)
313 bcache_nblks = bc->bcache_nblks;
239
240 /* bypass large requests, or when the cache is inactive */
314
315 /* bypass large requests, or when the cache is inactive */
241 if ((bcache_data == NULL) || ((size * 2 / bcache_blksize) > bcache_nblks)) {
316 if (bc == NULL ||
317 (offset == 0 && ((size * 2 / bcache_blksize) > bcache_nblks))) {
242 DEBUG("bypass %d from %d", size / bcache_blksize, blk);
243 bcache_bypasses++;
318 DEBUG("bypass %d from %d", size / bcache_blksize, blk);
319 bcache_bypasses++;
244 return(dd->dv_strategy(dd->dv_devdata, rw, blk, size, buf, rsize));
320 return (dd->dv_strategy(dd->dv_devdata, rw, blk, offset, size, buf,
321 rsize));
245 }
246
322 }
323
324 /* normalize offset */
325 while (offset >= bcache_blksize) {
326 blk++;
327 offset -= bcache_blksize;
328 }
329
247 switch (rw) {
248 case F_READ:
330 switch (rw) {
331 case F_READ:
249 return read_strategy(devdata, unit, rw, blk, size, buf, rsize);
332 nblk = size / bcache_blksize;
333 if (offset || (size != 0 && nblk == 0))
334 nblk++; /* read at least one block */
335
336 ret = 0;
337 total = 0;
338 while(size) {
339 cblk = bcache_nblks - BHASH(bc, blk); /* # of blocks left */
340 cblk = MIN(cblk, nblk);
341
342 if (size <= bcache_blksize)
343 csize = size;
344 else {
345 csize = cblk * bcache_blksize;
346 if (offset)
347 csize -= (bcache_blksize - offset);
348 }
349
350 ret = read_strategy(devdata, rw, blk, offset,
351 csize, buf+total, &isize);
352 if (ret != 0)
353 return (ret);
354 blk += (offset+isize) / bcache_blksize;
355 offset = 0;
356 total += isize;
357 size -= isize;
358 nblk = size / bcache_blksize;
359 }
360
361 if (rsize)
362 *rsize = total;
363
364 return (ret);
250 case F_WRITE:
365 case F_WRITE:
251 return write_strategy(devdata, unit, rw, blk, size, buf, rsize);
366 return write_strategy(devdata, rw, blk, offset, size, buf, rsize);
252 }
253 return -1;
254}
255
367 }
368 return -1;
369}
370
256
257/*
371/*
258 * Insert a block into the cache. Retire the oldest block to do so, if required.
259 *
260 * XXX the LRU algorithm will fail after 2^31 blocks have been transferred.
372 * Free allocated bcache instance
261 */
262static void
373 */
374static void
263bcache_insert(caddr_t buf, daddr_t blkno)
375bcache_free_instance(struct bcache *bc)
264{
376{
265 time_t now;
266 int cand, ocount;
267 u_int i;
268
269 time(&now);
270 cand = 0; /* assume the first block */
271 ocount = bcache_ctl[0].bc_count;
272
273 /* find the oldest block */
274 for (i = 1; i < bcache_nblks; i++) {
275 if (bcache_ctl[i].bc_blkno == blkno) {
276 /* reuse old entry */
277 cand = i;
278 break;
279 }
280 if (bcache_ctl[i].bc_count < ocount) {
281 ocount = bcache_ctl[i].bc_count;
282 cand = i;
283 }
377 if (bc != NULL) {
378 if (bc->bcache_ctl)
379 free(bc->bcache_ctl);
380 if (bc->bcache_data)
381 free(bc->bcache_data);
382 free(bc);
284 }
383 }
285
286 DEBUG("insert blk %d -> %d @ %d # %d", blkno, cand, now, bcache_bcount);
287 bcopy(buf, bcache_data + (bcache_blksize * cand), bcache_blksize);
288 bcache_ctl[cand].bc_blkno = blkno;
289 bcache_ctl[cand].bc_stamp = now;
290 bcache_ctl[cand].bc_count = bcache_bcount++;
291}
292
293/*
384}
385
386/*
294 * Look for a block in the cache. Blocks more than BCACHE_TIMEOUT seconds old
295 * may be stale (removable media) and thus are discarded. Copy the block out
296 * if successful and return zero, or return nonzero on failure.
387 * Insert a block into the cache.
297 */
388 */
298static int
299bcache_lookup(caddr_t buf, daddr_t blkno)
389static void
390bcache_insert(struct bcache *bc, daddr_t blkno)
300{
391{
301 time_t now;
302 u_int i;
392 u_int cand;
303
393
304 time(&now);
394 cand = BHASH(bc, blkno);
305
395
306 for (i = 0; i < bcache_nblks; i++)
307 /* cache hit? */
308 if ((bcache_ctl[i].bc_blkno == blkno) && ((bcache_ctl[i].bc_stamp + BCACHE_TIMEOUT) >= now)) {
309 bcopy(bcache_data + (bcache_blksize * i), buf, bcache_blksize);
310 DEBUG("hit blk %d <- %d (now %d then %d)", blkno, i, now, bcache_ctl[i].bc_stamp);
311 return(0);
312 }
313 return(ENOENT);
396 DEBUG("insert blk %llu -> %u # %d", blkno, cand, bcache_bcount);
397 bc->bcache_ctl[cand].bc_blkno = blkno;
398 bc->bcache_ctl[cand].bc_count = bcache_bcount++;
314}
315
316/*
317 * Invalidate a block from the cache.
318 */
319static void
399}
400
401/*
402 * Invalidate a block from the cache.
403 */
404static void
320bcache_invalidate(daddr_t blkno)
405bcache_invalidate(struct bcache *bc, daddr_t blkno)
321{
322 u_int i;
323
406{
407 u_int i;
408
324 for (i = 0; i < bcache_nblks; i++) {
325 if (bcache_ctl[i].bc_blkno == blkno) {
326 bcache_ctl[i].bc_count = -1;
327 bcache_ctl[i].bc_blkno = -1;
328 DEBUG("invalidate blk %d", blkno);
329 break;
330 }
409 i = BHASH(bc, blkno);
410 if (bc->bcache_ctl[i].bc_blkno == blkno) {
411 bc->bcache_ctl[i].bc_count = -1;
412 bc->bcache_ctl[i].bc_blkno = -1;
413 DEBUG("invalidate blk %llu", blkno);
331 }
332}
333
414 }
415}
416
417#ifndef BOOT2
334COMMAND_SET(bcachestat, "bcachestat", "get disk block cache stats", command_bcache);
335
336static int
337command_bcache(int argc, char *argv[])
338{
418COMMAND_SET(bcachestat, "bcachestat", "get disk block cache stats", command_bcache);
419
420static int
421command_bcache(int argc, char *argv[])
422{
339 u_int i;
340
341 for (i = 0; i < bcache_nblks; i++) {
342 printf("%08jx %04x %04x|", (uintmax_t)bcache_ctl[i].bc_blkno, (unsigned int)bcache_ctl[i].bc_stamp & 0xffff, bcache_ctl[i].bc_count & 0xffff);
343 if (((i + 1) % 4) == 0)
344 printf("\n");
423 if (argc != 1) {
424 command_errmsg = "wrong number of arguments";
425 return(CMD_ERROR);
345 }
426 }
346 printf("\n%d ops %d bypasses %d hits %d misses %d flushes\n", bcache_ops, bcache_bypasses, bcache_hits, bcache_misses, bcache_flushes);
427
428 printf("\ncache blocks: %d\n", bcache_total_nblks);
429 printf("cache blocksz: %d\n", bcache_blksize);
430 printf("cache readahead: %d\n", bcache_rablks);
431 printf("unit cache blocks: %d\n", bcache_unit_nblks);
432 printf("cached units: %d\n", bcache_units);
433 printf("%d ops %d bypasses %d hits %d misses\n", bcache_ops,
434 bcache_bypasses, bcache_hits, bcache_misses);
347 return(CMD_OK);
348}
435 return(CMD_OK);
436}
349
437#endif