FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_blist.c
1
2 /*
3 * BLIST.C - Bitmap allocator/deallocator, using a radix tree with hinting
4 *
5 * (c)Copyright 1998, Matthew Dillon. Terms for use and redistribution
6 * are covered by the BSD Copyright as found in /usr/src/COPYRIGHT.
7 *
8 * This module implements a general bitmap allocator/deallocator. The
9 * allocator eats around 2 bits per 'block'. The module does not
10 * try to interpret the meaning of a 'block' other then to return
11 * SWAPBLK_NONE on an allocation failure.
12 *
13 * A radix tree is used to maintain the bitmap. Two radix constants are
14 * involved: One for the bitmaps contained in the leaf nodes (typically
15 * 32), and one for the meta nodes (typically 16). Both meta and leaf
16 * nodes have a hint field. This field gives us a hint as to the largest
17 * free contiguous range of blocks under the node. It may contain a
18 * value that is too high, but will never contain a value that is too
19 * low. When the radix tree is searched, allocation failures in subtrees
20 * update the hint.
21 *
22 * The radix tree also implements two collapsed states for meta nodes:
23 * the ALL-ALLOCATED state and the ALL-FREE state. If a meta node is
24 * in either of these two states, all information contained underneath
25 * the node is considered stale. These states are used to optimize
26 * allocation and freeing operations.
27 *
28 * The hinting greatly increases code efficiency for allocations while
29 * the general radix structure optimizes both allocations and frees. The
30 * radix tree should be able to operate well no matter how much
31 * fragmentation there is and no matter how large a bitmap is used.
32 *
33 * Unlike the rlist code, the blist code wires all necessary memory at
34 * creation time. Neither allocations nor frees require interaction with
35 * the memory subsystem. In contrast, the rlist code may allocate memory
36 * on an rlist_free() call. The non-blocking features of the blist code
37 * are used to great advantage in the swap code (vm/nswap_pager.c). The
38 * rlist code uses a little less overall memory then the blist code (but
39 * due to swap interleaving not all that much less), but the blist code
40 * scales much, much better.
41 *
42 * LAYOUT: The radix tree is layed out recursively using a
43 * linear array. Each meta node is immediately followed (layed out
44 * sequentially in memory) by BLIST_META_RADIX lower level nodes. This
45 * is a recursive structure but one that can be easily scanned through
46 * a very simple 'skip' calculation. In order to support large radixes,
47 * portions of the tree may reside outside our memory allocation. We
48 * handle this with an early-termination optimization (when bighint is
49 * set to -1) on the scan. The memory allocation is only large enough
50 * to cover the number of blocks requested at creation time even if it
51 * must be encompassed in larger root-node radix.
52 *
53 * NOTE: the allocator cannot currently allocate more then
54 * BLIST_BMAP_RADIX blocks per call. It will panic with 'allocation too
55 * large' if you try. This is an area that could use improvement. The
56 * radix is large enough that this restriction does not effect the swap
57 * system, though. Currently only the allocation code is effected by
58 * this algorithmic unfeature. The freeing code can handle arbitrary
59 * ranges.
60 *
61 * This code can be compiled stand-alone for debugging.
62 *
63 * $FreeBSD: releng/5.0/sys/kern/subr_blist.c 96882 2002-05-18 23:46:04Z jhb $
64 */
65
66 #ifdef _KERNEL
67
68 #include <sys/param.h>
69 #include <sys/systm.h>
70 #include <sys/lock.h>
71 #include <sys/kernel.h>
72 #include <sys/blist.h>
73 #include <sys/malloc.h>
74 #include <sys/proc.h>
75 #include <sys/mutex.h>
76 #include <vm/vm.h>
77 #include <vm/vm_object.h>
78 #include <vm/vm_kern.h>
79 #include <vm/vm_extern.h>
80 #include <vm/vm_page.h>
81
82 #else
83
84 #ifndef BLIST_NO_DEBUG
85 #define BLIST_DEBUG
86 #endif
87
88 #define SWAPBLK_NONE ((daddr_t)-1)
89
90 #include <sys/types.h>
91 #include <stdio.h>
92 #include <string.h>
93 #include <stdlib.h>
94 #include <stdarg.h>
95
96 #define malloc(a,b,c) malloc(a)
97 #define free(a,b) free(a)
98
99 typedef unsigned int u_daddr_t;
100
101 #include <sys/blist.h>
102
103 void panic(const char *ctl, ...);
104
105 #endif
106
107 /*
108 * static support functions
109 */
110
111 static daddr_t blst_leaf_alloc(blmeta_t *scan, daddr_t blk, int count);
112 static daddr_t blst_meta_alloc(blmeta_t *scan, daddr_t blk,
113 daddr_t count, daddr_t radix, int skip);
114 static void blst_leaf_free(blmeta_t *scan, daddr_t relblk, int count);
115 static void blst_meta_free(blmeta_t *scan, daddr_t freeBlk, daddr_t count,
116 daddr_t radix, int skip, daddr_t blk);
117 static void blst_copy(blmeta_t *scan, daddr_t blk, daddr_t radix,
118 daddr_t skip, blist_t dest, daddr_t count);
119 static daddr_t blst_radix_init(blmeta_t *scan, daddr_t radix,
120 int skip, daddr_t count);
121 #ifndef _KERNEL
122 static void blst_radix_print(blmeta_t *scan, daddr_t blk,
123 daddr_t radix, int skip, int tab);
124 #endif
125
126 #ifdef _KERNEL
127 static MALLOC_DEFINE(M_SWAP, "SWAP", "Swap space");
128 #endif
129
130 /*
131 * blist_create() - create a blist capable of handling up to the specified
132 * number of blocks
133 *
134 * blocks must be greater then 0
135 *
136 * The smallest blist consists of a single leaf node capable of
137 * managing BLIST_BMAP_RADIX blocks.
138 */
139
140 blist_t
141 blist_create(daddr_t blocks)
142 {
143 blist_t bl;
144 int radix;
145 int skip = 0;
146
147 /*
148 * Calculate radix and skip field used for scanning.
149 */
150 radix = BLIST_BMAP_RADIX;
151
152 while (radix < blocks) {
153 radix <<= BLIST_META_RADIX_SHIFT;
154 skip = (skip + 1) << BLIST_META_RADIX_SHIFT;
155 }
156
157 bl = malloc(sizeof(struct blist), M_SWAP, M_WAITOK | M_ZERO);
158
159 bl->bl_blocks = blocks;
160 bl->bl_radix = radix;
161 bl->bl_skip = skip;
162 bl->bl_rootblks = 1 +
163 blst_radix_init(NULL, bl->bl_radix, bl->bl_skip, blocks);
164 bl->bl_root = malloc(sizeof(blmeta_t) * bl->bl_rootblks, M_SWAP, M_WAITOK);
165
166 #if defined(BLIST_DEBUG)
167 printf(
168 "BLIST representing %d blocks (%d MB of swap)"
169 ", requiring %dK of ram\n",
170 bl->bl_blocks,
171 bl->bl_blocks * 4 / 1024,
172 (bl->bl_rootblks * sizeof(blmeta_t) + 1023) / 1024
173 );
174 printf("BLIST raw radix tree contains %d records\n", bl->bl_rootblks);
175 #endif
176 blst_radix_init(bl->bl_root, bl->bl_radix, bl->bl_skip, blocks);
177
178 return(bl);
179 }
180
181 void
182 blist_destroy(blist_t bl)
183 {
184 free(bl->bl_root, M_SWAP);
185 free(bl, M_SWAP);
186 }
187
188 /*
189 * blist_alloc() - reserve space in the block bitmap. Return the base
190 * of a contiguous region or SWAPBLK_NONE if space could
191 * not be allocated.
192 */
193
194 daddr_t
195 blist_alloc(blist_t bl, daddr_t count)
196 {
197 daddr_t blk = SWAPBLK_NONE;
198
199 if (bl) {
200 if (bl->bl_radix == BLIST_BMAP_RADIX)
201 blk = blst_leaf_alloc(bl->bl_root, 0, count);
202 else
203 blk = blst_meta_alloc(bl->bl_root, 0, count, bl->bl_radix, bl->bl_skip);
204 if (blk != SWAPBLK_NONE)
205 bl->bl_free -= count;
206 }
207 return(blk);
208 }
209
210 /*
211 * blist_free() - free up space in the block bitmap. Return the base
212 * of a contiguous region. Panic if an inconsistancy is
213 * found.
214 */
215
216 void
217 blist_free(blist_t bl, daddr_t blkno, daddr_t count)
218 {
219 if (bl) {
220 if (bl->bl_radix == BLIST_BMAP_RADIX)
221 blst_leaf_free(bl->bl_root, blkno, count);
222 else
223 blst_meta_free(bl->bl_root, blkno, count, bl->bl_radix, bl->bl_skip, 0);
224 bl->bl_free += count;
225 }
226 }
227
228 /*
229 * blist_resize() - resize an existing radix tree to handle the
230 * specified number of blocks. This will reallocate
231 * the tree and transfer the previous bitmap to the new
232 * one. When extending the tree you can specify whether
233 * the new blocks are to left allocated or freed.
234 */
235
236 void
237 blist_resize(blist_t *pbl, daddr_t count, int freenew)
238 {
239 blist_t newbl = blist_create(count);
240 blist_t save = *pbl;
241
242 *pbl = newbl;
243 if (count > save->bl_blocks)
244 count = save->bl_blocks;
245 blst_copy(save->bl_root, 0, save->bl_radix, save->bl_skip, newbl, count);
246
247 /*
248 * If resizing upwards, should we free the new space or not?
249 */
250 if (freenew && count < newbl->bl_blocks) {
251 blist_free(newbl, count, newbl->bl_blocks - count);
252 }
253 blist_destroy(save);
254 }
255
256 #ifdef BLIST_DEBUG
257
258 /*
259 * blist_print() - dump radix tree
260 */
261
262 void
263 blist_print(blist_t bl)
264 {
265 printf("BLIST {\n");
266 blst_radix_print(bl->bl_root, 0, bl->bl_radix, bl->bl_skip, 4);
267 printf("}\n");
268 }
269
270 #endif
271
272 /************************************************************************
273 * ALLOCATION SUPPORT FUNCTIONS *
274 ************************************************************************
275 *
276 * These support functions do all the actual work. They may seem
277 * rather longish, but that's because I've commented them up. The
278 * actual code is straight forward.
279 *
280 */
281
282 /*
283 * blist_leaf_alloc() - allocate at a leaf in the radix tree (a bitmap).
284 *
285 * This is the core of the allocator and is optimized for the 1 block
286 * and the BLIST_BMAP_RADIX block allocation cases. Other cases are
287 * somewhat slower. The 1 block allocation case is log2 and extremely
288 * quick.
289 */
290
291 static daddr_t
292 blst_leaf_alloc(
293 blmeta_t *scan,
294 daddr_t blk,
295 int count
296 ) {
297 u_daddr_t orig = scan->u.bmu_bitmap;
298
299 if (orig == 0) {
300 /*
301 * Optimize bitmap all-allocated case. Also, count = 1
302 * case assumes at least 1 bit is free in the bitmap, so
303 * we have to take care of this case here.
304 */
305 scan->bm_bighint = 0;
306 return(SWAPBLK_NONE);
307 }
308 if (count == 1) {
309 /*
310 * Optimized code to allocate one bit out of the bitmap
311 */
312 u_daddr_t mask;
313 int j = BLIST_BMAP_RADIX/2;
314 int r = 0;
315
316 mask = (u_daddr_t)-1 >> (BLIST_BMAP_RADIX/2);
317
318 while (j) {
319 if ((orig & mask) == 0) {
320 r += j;
321 orig >>= j;
322 }
323 j >>= 1;
324 mask >>= j;
325 }
326 scan->u.bmu_bitmap &= ~(1 << r);
327 return(blk + r);
328 }
329 if (count <= BLIST_BMAP_RADIX) {
330 /*
331 * non-optimized code to allocate N bits out of the bitmap.
332 * The more bits, the faster the code runs. It will run
333 * the slowest allocating 2 bits, but since there aren't any
334 * memory ops in the core loop (or shouldn't be, anyway),
335 * you probably won't notice the difference.
336 */
337 int j;
338 int n = BLIST_BMAP_RADIX - count;
339 u_daddr_t mask;
340
341 mask = (u_daddr_t)-1 >> n;
342
343 for (j = 0; j <= n; ++j) {
344 if ((orig & mask) == mask) {
345 scan->u.bmu_bitmap &= ~mask;
346 return(blk + j);
347 }
348 mask = (mask << 1);
349 }
350 }
351 /*
352 * We couldn't allocate count in this subtree, update bighint.
353 */
354 scan->bm_bighint = count - 1;
355 return(SWAPBLK_NONE);
356 }
357
358 /*
359 * blist_meta_alloc() - allocate at a meta in the radix tree.
360 *
361 * Attempt to allocate at a meta node. If we can't, we update
362 * bighint and return a failure. Updating bighint optimize future
363 * calls that hit this node. We have to check for our collapse cases
364 * and we have a few optimizations strewn in as well.
365 */
366
367 static daddr_t
368 blst_meta_alloc(
369 blmeta_t *scan,
370 daddr_t blk,
371 daddr_t count,
372 daddr_t radix,
373 int skip
374 ) {
375 int i;
376 int next_skip = (skip >> BLIST_META_RADIX_SHIFT);
377
378 if (scan->u.bmu_avail == 0) {
379 /*
380 * ALL-ALLOCATED special case
381 */
382 scan->bm_bighint = count;
383 return(SWAPBLK_NONE);
384 }
385
386 if (scan->u.bmu_avail == radix) {
387 radix >>= BLIST_META_RADIX_SHIFT;
388
389 /*
390 * ALL-FREE special case, initialize uninitialize
391 * sublevel.
392 */
393 for (i = 1; i <= skip; i += next_skip) {
394 if (scan[i].bm_bighint == (daddr_t)-1)
395 break;
396 if (next_skip == 1) {
397 scan[i].u.bmu_bitmap = (u_daddr_t)-1;
398 scan[i].bm_bighint = BLIST_BMAP_RADIX;
399 } else {
400 scan[i].bm_bighint = radix;
401 scan[i].u.bmu_avail = radix;
402 }
403 }
404 } else {
405 radix >>= BLIST_META_RADIX_SHIFT;
406 }
407
408 for (i = 1; i <= skip; i += next_skip) {
409 if (count <= scan[i].bm_bighint) {
410 /*
411 * count fits in object
412 */
413 daddr_t r;
414 if (next_skip == 1) {
415 r = blst_leaf_alloc(&scan[i], blk, count);
416 } else {
417 r = blst_meta_alloc(&scan[i], blk, count, radix, next_skip - 1);
418 }
419 if (r != SWAPBLK_NONE) {
420 scan->u.bmu_avail -= count;
421 if (scan->bm_bighint > scan->u.bmu_avail)
422 scan->bm_bighint = scan->u.bmu_avail;
423 return(r);
424 }
425 } else if (scan[i].bm_bighint == (daddr_t)-1) {
426 /*
427 * Terminator
428 */
429 break;
430 } else if (count > radix) {
431 /*
432 * count does not fit in object even if it were
433 * complete free.
434 */
435 panic("blist_meta_alloc: allocation too large");
436 }
437 blk += radix;
438 }
439
440 /*
441 * We couldn't allocate count in this subtree, update bighint.
442 */
443 if (scan->bm_bighint >= count)
444 scan->bm_bighint = count - 1;
445 return(SWAPBLK_NONE);
446 }
447
448 /*
449 * BLST_LEAF_FREE() - free allocated block from leaf bitmap
450 *
451 */
452
453 static void
454 blst_leaf_free(
455 blmeta_t *scan,
456 daddr_t blk,
457 int count
458 ) {
459 /*
460 * free some data in this bitmap
461 *
462 * e.g.
463 * 0000111111111110000
464 * \_________/\__/
465 * v n
466 */
467 int n = blk & (BLIST_BMAP_RADIX - 1);
468 u_daddr_t mask;
469
470 mask = ((u_daddr_t)-1 << n) &
471 ((u_daddr_t)-1 >> (BLIST_BMAP_RADIX - count - n));
472
473 if (scan->u.bmu_bitmap & mask)
474 panic("blst_radix_free: freeing free block");
475 scan->u.bmu_bitmap |= mask;
476
477 /*
478 * We could probably do a better job here. We are required to make
479 * bighint at least as large as the biggest contiguous block of
480 * data. If we just shoehorn it, a little extra overhead will
481 * be incured on the next allocation (but only that one typically).
482 */
483 scan->bm_bighint = BLIST_BMAP_RADIX;
484 }
485
486 /*
487 * BLST_META_FREE() - free allocated blocks from radix tree meta info
488 *
489 * This support routine frees a range of blocks from the bitmap.
490 * The range must be entirely enclosed by this radix node. If a
491 * meta node, we break the range down recursively to free blocks
492 * in subnodes (which means that this code can free an arbitrary
493 * range whereas the allocation code cannot allocate an arbitrary
494 * range).
495 */
496
497 static void
498 blst_meta_free(
499 blmeta_t *scan,
500 daddr_t freeBlk,
501 daddr_t count,
502 daddr_t radix,
503 int skip,
504 daddr_t blk
505 ) {
506 int i;
507 int next_skip = (skip >> BLIST_META_RADIX_SHIFT);
508
509 #if 0
510 printf("FREE (%x,%d) FROM (%x,%d)\n",
511 freeBlk, count,
512 blk, radix
513 );
514 #endif
515
516 if (scan->u.bmu_avail == 0) {
517 /*
518 * ALL-ALLOCATED special case, with possible
519 * shortcut to ALL-FREE special case.
520 */
521 scan->u.bmu_avail = count;
522 scan->bm_bighint = count;
523
524 if (count != radix) {
525 for (i = 1; i <= skip; i += next_skip) {
526 if (scan[i].bm_bighint == (daddr_t)-1)
527 break;
528 scan[i].bm_bighint = 0;
529 if (next_skip == 1) {
530 scan[i].u.bmu_bitmap = 0;
531 } else {
532 scan[i].u.bmu_avail = 0;
533 }
534 }
535 /* fall through */
536 }
537 } else {
538 scan->u.bmu_avail += count;
539 /* scan->bm_bighint = radix; */
540 }
541
542 /*
543 * ALL-FREE special case.
544 */
545
546 if (scan->u.bmu_avail == radix)
547 return;
548 if (scan->u.bmu_avail > radix)
549 panic("blst_meta_free: freeing already free blocks (%lld) %lld/%lld",
550 (long long)count, (long long)scan->u.bmu_avail,
551 (long long)radix);
552
553 /*
554 * Break the free down into its components
555 */
556
557 radix >>= BLIST_META_RADIX_SHIFT;
558
559 i = (freeBlk - blk) / radix;
560 blk += i * radix;
561 i = i * next_skip + 1;
562
563 while (i <= skip && blk < freeBlk + count) {
564 daddr_t v;
565
566 v = blk + radix - freeBlk;
567 if (v > count)
568 v = count;
569
570 if (scan->bm_bighint == (daddr_t)-1)
571 panic("blst_meta_free: freeing unexpected range");
572
573 if (next_skip == 1) {
574 blst_leaf_free(&scan[i], freeBlk, v);
575 } else {
576 blst_meta_free(&scan[i], freeBlk, v, radix, next_skip - 1, blk);
577 }
578 if (scan->bm_bighint < scan[i].bm_bighint)
579 scan->bm_bighint = scan[i].bm_bighint;
580 count -= v;
581 freeBlk += v;
582 blk += radix;
583 i += next_skip;
584 }
585 }
586
587 /*
588 * BLIST_RADIX_COPY() - copy one radix tree to another
589 *
590 * Locates free space in the source tree and frees it in the destination
591 * tree. The space may not already be free in the destination.
592 */
593
594 static void blst_copy(
595 blmeta_t *scan,
596 daddr_t blk,
597 daddr_t radix,
598 daddr_t skip,
599 blist_t dest,
600 daddr_t count
601 ) {
602 int next_skip;
603 int i;
604
605 /*
606 * Leaf node
607 */
608
609 if (radix == BLIST_BMAP_RADIX) {
610 u_daddr_t v = scan->u.bmu_bitmap;
611
612 if (v == (u_daddr_t)-1) {
613 blist_free(dest, blk, count);
614 } else if (v != 0) {
615 int i;
616
617 for (i = 0; i < BLIST_BMAP_RADIX && i < count; ++i) {
618 if (v & (1 << i))
619 blist_free(dest, blk + i, 1);
620 }
621 }
622 return;
623 }
624
625 /*
626 * Meta node
627 */
628
629 if (scan->u.bmu_avail == 0) {
630 /*
631 * Source all allocated, leave dest allocated
632 */
633 return;
634 }
635 if (scan->u.bmu_avail == radix) {
636 /*
637 * Source all free, free entire dest
638 */
639 if (count < radix)
640 blist_free(dest, blk, count);
641 else
642 blist_free(dest, blk, radix);
643 return;
644 }
645
646
647 radix >>= BLIST_META_RADIX_SHIFT;
648 next_skip = (skip >> BLIST_META_RADIX_SHIFT);
649
650 for (i = 1; count && i <= skip; i += next_skip) {
651 if (scan[i].bm_bighint == (daddr_t)-1)
652 break;
653
654 if (count >= radix) {
655 blst_copy(
656 &scan[i],
657 blk,
658 radix,
659 next_skip - 1,
660 dest,
661 radix
662 );
663 count -= radix;
664 } else {
665 if (count) {
666 blst_copy(
667 &scan[i],
668 blk,
669 radix,
670 next_skip - 1,
671 dest,
672 count
673 );
674 }
675 count = 0;
676 }
677 blk += radix;
678 }
679 }
680
681 /*
682 * BLST_RADIX_INIT() - initialize radix tree
683 *
684 * Initialize our meta structures and bitmaps and calculate the exact
685 * amount of space required to manage 'count' blocks - this space may
686 * be considerably less then the calculated radix due to the large
687 * RADIX values we use.
688 */
689
690 static daddr_t
691 blst_radix_init(blmeta_t *scan, daddr_t radix, int skip, daddr_t count)
692 {
693 int i;
694 int next_skip;
695 daddr_t memindex = 0;
696
697 /*
698 * Leaf node
699 */
700
701 if (radix == BLIST_BMAP_RADIX) {
702 if (scan) {
703 scan->bm_bighint = 0;
704 scan->u.bmu_bitmap = 0;
705 }
706 return(memindex);
707 }
708
709 /*
710 * Meta node. If allocating the entire object we can special
711 * case it. However, we need to figure out how much memory
712 * is required to manage 'count' blocks, so we continue on anyway.
713 */
714
715 if (scan) {
716 scan->bm_bighint = 0;
717 scan->u.bmu_avail = 0;
718 }
719
720 radix >>= BLIST_META_RADIX_SHIFT;
721 next_skip = (skip >> BLIST_META_RADIX_SHIFT);
722
723 for (i = 1; i <= skip; i += next_skip) {
724 if (count >= radix) {
725 /*
726 * Allocate the entire object
727 */
728 memindex = i + blst_radix_init(
729 ((scan) ? &scan[i] : NULL),
730 radix,
731 next_skip - 1,
732 radix
733 );
734 count -= radix;
735 } else if (count > 0) {
736 /*
737 * Allocate a partial object
738 */
739 memindex = i + blst_radix_init(
740 ((scan) ? &scan[i] : NULL),
741 radix,
742 next_skip - 1,
743 count
744 );
745 count = 0;
746 } else {
747 /*
748 * Add terminator and break out
749 */
750 if (scan)
751 scan[i].bm_bighint = (daddr_t)-1;
752 break;
753 }
754 }
755 if (memindex < i)
756 memindex = i;
757 return(memindex);
758 }
759
760 #ifdef BLIST_DEBUG
761
762 static void
763 blst_radix_print(blmeta_t *scan, daddr_t blk, daddr_t radix, int skip, int tab)
764 {
765 int i;
766 int next_skip;
767 int lastState = 0;
768
769 if (radix == BLIST_BMAP_RADIX) {
770 printf(
771 "%*.*s(%04x,%d): bitmap %08x big=%d\n",
772 tab, tab, "",
773 blk, radix,
774 scan->u.bmu_bitmap,
775 scan->bm_bighint
776 );
777 return;
778 }
779
780 if (scan->u.bmu_avail == 0) {
781 printf(
782 "%*.*s(%04x,%d) ALL ALLOCATED\n",
783 tab, tab, "",
784 blk,
785 radix
786 );
787 return;
788 }
789 if (scan->u.bmu_avail == radix) {
790 printf(
791 "%*.*s(%04x,%d) ALL FREE\n",
792 tab, tab, "",
793 blk,
794 radix
795 );
796 return;
797 }
798
799 printf(
800 "%*.*s(%04x,%d): subtree (%d/%d) big=%d {\n",
801 tab, tab, "",
802 blk, radix,
803 scan->u.bmu_avail,
804 radix,
805 scan->bm_bighint
806 );
807
808 radix >>= BLIST_META_RADIX_SHIFT;
809 next_skip = (skip >> BLIST_META_RADIX_SHIFT);
810 tab += 4;
811
812 for (i = 1; i <= skip; i += next_skip) {
813 if (scan[i].bm_bighint == (daddr_t)-1) {
814 printf(
815 "%*.*s(%04x,%d): Terminator\n",
816 tab, tab, "",
817 blk, radix
818 );
819 lastState = 0;
820 break;
821 }
822 blst_radix_print(
823 &scan[i],
824 blk,
825 radix,
826 next_skip - 1,
827 tab
828 );
829 blk += radix;
830 }
831 tab -= 4;
832
833 printf(
834 "%*.*s}\n",
835 tab, tab, ""
836 );
837 }
838
839 #endif
840
841 #ifdef BLIST_DEBUG
842
843 int
844 main(int ac, char **av)
845 {
846 int size = 1024;
847 int i;
848 blist_t bl;
849
850 for (i = 1; i < ac; ++i) {
851 const char *ptr = av[i];
852 if (*ptr != '-') {
853 size = strtol(ptr, NULL, 0);
854 continue;
855 }
856 ptr += 2;
857 fprintf(stderr, "Bad option: %s\n", ptr - 2);
858 exit(1);
859 }
860 bl = blist_create(size);
861 blist_free(bl, 0, size);
862
863 for (;;) {
864 char buf[1024];
865 daddr_t da = 0;
866 daddr_t count = 0;
867
868
869 printf("%d/%d/%d> ", bl->bl_free, size, bl->bl_radix);
870 fflush(stdout);
871 if (fgets(buf, sizeof(buf), stdin) == NULL)
872 break;
873 switch(buf[0]) {
874 case 'r':
875 if (sscanf(buf + 1, "%d", &count) == 1) {
876 blist_resize(&bl, count, 1);
877 } else {
878 printf("?\n");
879 }
880 case 'p':
881 blist_print(bl);
882 break;
883 case 'a':
884 if (sscanf(buf + 1, "%d", &count) == 1) {
885 daddr_t blk = blist_alloc(bl, count);
886 printf(" R=%04x\n", blk);
887 } else {
888 printf("?\n");
889 }
890 break;
891 case 'f':
892 if (sscanf(buf + 1, "%x %d", &da, &count) == 2) {
893 blist_free(bl, da, count);
894 } else {
895 printf("?\n");
896 }
897 break;
898 case '?':
899 case 'h':
900 puts(
901 "p -print\n"
902 "a %d -allocate\n"
903 "f %x %d -free\n"
904 "r %d -resize\n"
905 "h/? -help"
906 );
907 break;
908 default:
909 printf("?\n");
910 break;
911 }
912 }
913 return(0);
914 }
915
916 void
917 panic(const char *ctl, ...)
918 {
919 va_list va;
920
921 va_start(va, ctl);
922 vfprintf(stderr, ctl, va);
923 fprintf(stderr, "\n");
924 va_end(va);
925 exit(1);
926 }
927
928 #endif
929
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