1 /* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright(c) 2010-2014 Intel Corporation
10 #include <sys/queue.h>
12 #include <rte_memory.h>
14 #include <rte_launch.h>
15 #include <rte_per_lcore.h>
16 #include <rte_lcore.h>
17 #include <rte_debug.h>
18 #include <rte_common.h>
19 #include <rte_spinlock.h>
21 #include "eal_memalloc.h"
22 #include "malloc_elem.h"
23 #include "malloc_heap.h"
25 #define MIN_DATA_SIZE (RTE_CACHE_LINE_SIZE)
28 * Initialize a general malloc_elem header structure
31 malloc_elem_init(struct malloc_elem *elem, struct malloc_heap *heap,
32 struct rte_memseg_list *msl, size_t size)
38 memset(&elem->free_list, 0, sizeof(elem->free_list));
39 elem->state = ELEM_FREE;
47 malloc_elem_insert(struct malloc_elem *elem)
49 struct malloc_elem *prev_elem, *next_elem;
50 struct malloc_heap *heap = elem->heap;
52 if (heap->first == NULL && heap->last == NULL) {
58 } else if (elem < heap->first) {
59 /* if lower than start */
61 next_elem = heap->first;
63 } else if (elem > heap->last) {
64 /* if higher than end */
65 prev_elem = heap->last;
69 /* the new memory is somewhere inbetween start and end */
70 uint64_t dist_from_start, dist_from_end;
72 dist_from_end = RTE_PTR_DIFF(heap->last, elem);
73 dist_from_start = RTE_PTR_DIFF(elem, heap->first);
75 /* check which is closer, and find closest list entries */
76 if (dist_from_start < dist_from_end) {
77 prev_elem = heap->first;
78 while (prev_elem->next < elem)
79 prev_elem = prev_elem->next;
80 next_elem = prev_elem->next;
82 next_elem = heap->last;
83 while (next_elem->prev > elem)
84 next_elem = next_elem->prev;
85 prev_elem = next_elem->prev;
89 /* insert new element */
90 elem->prev = prev_elem;
91 elem->next = next_elem;
93 prev_elem->next = elem;
95 next_elem->prev = elem;
99 * Attempt to find enough physically contiguous memory in this block to store
100 * our data. Assume that element has at least enough space to fit in the data,
101 * so we just check the page addresses.
104 elem_check_phys_contig(const struct rte_memseg_list *msl,
105 void *start, size_t size)
107 return eal_memalloc_is_contig(msl, start, size);
111 * calculate the starting point of where data of the requested size
112 * and alignment would fit in the current element. If the data doesn't
116 elem_start_pt(struct malloc_elem *elem, size_t size, unsigned align,
117 size_t bound, bool contig)
119 size_t elem_size = elem->size;
122 * we're allocating from the end, so adjust the size of element by
125 while (elem_size >= size) {
126 const size_t bmask = ~(bound - 1);
127 uintptr_t end_pt = (uintptr_t)elem +
128 elem_size - MALLOC_ELEM_TRAILER_LEN;
129 uintptr_t new_data_start = RTE_ALIGN_FLOOR((end_pt - size),
131 uintptr_t new_elem_start;
134 if ((new_data_start & bmask) != ((end_pt - 1) & bmask)) {
135 end_pt = RTE_ALIGN_FLOOR(end_pt, bound);
136 new_data_start = RTE_ALIGN_FLOOR((end_pt - size),
138 end_pt = new_data_start + size;
140 if (((end_pt - 1) & bmask) != (new_data_start & bmask))
144 new_elem_start = new_data_start - MALLOC_ELEM_HEADER_LEN;
146 /* if the new start point is before the exist start,
149 if (new_elem_start < (uintptr_t)elem)
153 size_t new_data_size = end_pt - new_data_start;
156 * if physical contiguousness was requested and we
157 * couldn't fit all data into one physically contiguous
158 * block, try again with lower addresses.
160 if (!elem_check_phys_contig(elem->msl,
161 (void *)new_data_start,
167 return (void *)new_elem_start;
173 * use elem_start_pt to determine if we get meet the size and
174 * alignment request from the current element
177 malloc_elem_can_hold(struct malloc_elem *elem, size_t size, unsigned align,
178 size_t bound, bool contig)
180 return elem_start_pt(elem, size, align, bound, contig) != NULL;
184 * split an existing element into two smaller elements at the given
185 * split_pt parameter.
188 split_elem(struct malloc_elem *elem, struct malloc_elem *split_pt)
190 struct malloc_elem *next_elem = elem->next;
191 const size_t old_elem_size = (uintptr_t)split_pt - (uintptr_t)elem;
192 const size_t new_elem_size = elem->size - old_elem_size;
194 malloc_elem_init(split_pt, elem->heap, elem->msl, new_elem_size);
195 split_pt->prev = elem;
196 split_pt->next = next_elem;
198 next_elem->prev = split_pt;
200 elem->heap->last = split_pt;
201 elem->next = split_pt;
202 elem->size = old_elem_size;
207 * our malloc heap is a doubly linked list, so doubly remove our element.
209 static void __rte_unused
210 remove_elem(struct malloc_elem *elem)
212 struct malloc_elem *next, *prev;
219 elem->heap->last = prev;
223 elem->heap->first = next;
230 next_elem_is_adjacent(struct malloc_elem *elem)
232 return elem->next == RTE_PTR_ADD(elem, elem->size);
236 prev_elem_is_adjacent(struct malloc_elem *elem)
238 return elem == RTE_PTR_ADD(elem->prev, elem->prev->size);
242 * Given an element size, compute its freelist index.
243 * We free an element into the freelist containing similarly-sized elements.
244 * We try to allocate elements starting with the freelist containing
245 * similarly-sized elements, and if necessary, we search freelists
246 * containing larger elements.
248 * Example element size ranges for a heap with five free lists:
249 * heap->free_head[0] - (0 , 2^8]
250 * heap->free_head[1] - (2^8 , 2^10]
251 * heap->free_head[2] - (2^10 ,2^12]
252 * heap->free_head[3] - (2^12, 2^14]
253 * heap->free_head[4] - (2^14, MAX_SIZE]
256 malloc_elem_free_list_index(size_t size)
258 #define MALLOC_MINSIZE_LOG2 8
259 #define MALLOC_LOG2_INCREMENT 2
264 if (size <= (1UL << MALLOC_MINSIZE_LOG2))
267 /* Find next power of 2 >= size. */
268 log2 = sizeof(size) * 8 - __builtin_clzl(size-1);
270 /* Compute freelist index, based on log2(size). */
271 index = (log2 - MALLOC_MINSIZE_LOG2 + MALLOC_LOG2_INCREMENT - 1) /
272 MALLOC_LOG2_INCREMENT;
274 return index <= RTE_HEAP_NUM_FREELISTS-1?
275 index: RTE_HEAP_NUM_FREELISTS-1;
279 * Add the specified element to its heap's free list.
282 malloc_elem_free_list_insert(struct malloc_elem *elem)
286 idx = malloc_elem_free_list_index(elem->size - MALLOC_ELEM_HEADER_LEN);
287 elem->state = ELEM_FREE;
288 LIST_INSERT_HEAD(&elem->heap->free_head[idx], elem, free_list);
292 * Remove the specified element from its heap's free list.
295 malloc_elem_free_list_remove(struct malloc_elem *elem)
297 LIST_REMOVE(elem, free_list);
301 * reserve a block of data in an existing malloc_elem. If the malloc_elem
302 * is much larger than the data block requested, we split the element in two.
303 * This function is only called from malloc_heap_alloc so parameter checking
304 * is not done here, as it's done there previously.
307 malloc_elem_alloc(struct malloc_elem *elem, size_t size, unsigned align,
308 size_t bound, bool contig)
310 struct malloc_elem *new_elem = elem_start_pt(elem, size, align, bound,
312 const size_t old_elem_size = (uintptr_t)new_elem - (uintptr_t)elem;
313 const size_t trailer_size = elem->size - old_elem_size - size -
314 MALLOC_ELEM_OVERHEAD;
316 malloc_elem_free_list_remove(elem);
318 if (trailer_size > MALLOC_ELEM_OVERHEAD + MIN_DATA_SIZE) {
319 /* split it, too much free space after elem */
320 struct malloc_elem *new_free_elem =
321 RTE_PTR_ADD(new_elem, size + MALLOC_ELEM_OVERHEAD);
323 split_elem(elem, new_free_elem);
324 malloc_elem_free_list_insert(new_free_elem);
326 if (elem == elem->heap->last)
327 elem->heap->last = new_free_elem;
330 if (old_elem_size < MALLOC_ELEM_OVERHEAD + MIN_DATA_SIZE) {
331 /* don't split it, pad the element instead */
332 elem->state = ELEM_BUSY;
333 elem->pad = old_elem_size;
335 /* put a dummy header in padding, to point to real element header */
336 if (elem->pad > 0) { /* pad will be at least 64-bytes, as everything
337 * is cache-line aligned */
338 new_elem->pad = elem->pad;
339 new_elem->state = ELEM_PAD;
340 new_elem->size = elem->size - elem->pad;
341 set_header(new_elem);
347 /* we are going to split the element in two. The original element
348 * remains free, and the new element is the one allocated.
349 * Re-insert original element, in case its new size makes it
350 * belong on a different list.
352 split_elem(elem, new_elem);
353 new_elem->state = ELEM_BUSY;
354 malloc_elem_free_list_insert(elem);
360 * join two struct malloc_elem together. elem1 and elem2 must
361 * be contiguous in memory.
364 join_elem(struct malloc_elem *elem1, struct malloc_elem *elem2)
366 struct malloc_elem *next = elem2->next;
367 elem1->size += elem2->size;
371 elem1->heap->last = elem1;
376 malloc_elem_join_adjacent_free(struct malloc_elem *elem)
379 * check if next element exists, is adjacent and is free, if so join
380 * with it, need to remove from free list.
382 if (elem->next != NULL && elem->next->state == ELEM_FREE &&
383 next_elem_is_adjacent(elem)) {
386 /* we will want to erase the trailer and header */
387 erase = RTE_PTR_SUB(elem->next, MALLOC_ELEM_TRAILER_LEN);
389 /* remove from free list, join to this one */
390 malloc_elem_free_list_remove(elem->next);
391 join_elem(elem, elem->next);
393 /* erase header and trailer */
394 memset(erase, 0, MALLOC_ELEM_OVERHEAD);
398 * check if prev element exists, is adjacent and is free, if so join
399 * with it, need to remove from free list.
401 if (elem->prev != NULL && elem->prev->state == ELEM_FREE &&
402 prev_elem_is_adjacent(elem)) {
403 struct malloc_elem *new_elem;
406 /* we will want to erase trailer and header */
407 erase = RTE_PTR_SUB(elem, MALLOC_ELEM_TRAILER_LEN);
409 /* remove from free list, join to this one */
410 malloc_elem_free_list_remove(elem->prev);
412 new_elem = elem->prev;
413 join_elem(new_elem, elem);
415 /* erase header and trailer */
416 memset(erase, 0, MALLOC_ELEM_OVERHEAD);
425 * free a malloc_elem block by adding it to the free list. If the
426 * blocks either immediately before or immediately after newly freed block
427 * are also free, the blocks are merged together.
430 malloc_elem_free(struct malloc_elem *elem)
435 ptr = RTE_PTR_ADD(elem, sizeof(*elem));
436 data_len = elem->size - MALLOC_ELEM_OVERHEAD;
438 elem = malloc_elem_join_adjacent_free(elem);
440 malloc_elem_free_list_insert(elem);
442 /* decrease heap's count of allocated elements */
443 elem->heap->alloc_count--;
445 memset(ptr, 0, data_len);
450 /* assume all checks were already done */
452 malloc_elem_hide_region(struct malloc_elem *elem, void *start, size_t len)
454 struct malloc_elem *hide_start, *hide_end, *prev, *next;
455 size_t len_before, len_after;
458 hide_end = RTE_PTR_ADD(start, len);
463 /* we cannot do anything with non-adjacent elements */
464 if (next && next_elem_is_adjacent(elem)) {
465 len_after = RTE_PTR_DIFF(next, hide_end);
466 if (len_after >= MALLOC_ELEM_OVERHEAD + MIN_DATA_SIZE) {
468 split_elem(elem, hide_end);
470 malloc_elem_free_list_insert(hide_end);
471 } else if (len_after >= MALLOC_ELEM_HEADER_LEN) {
472 /* shrink current element */
473 elem->size -= len_after;
474 memset(hide_end, 0, sizeof(*hide_end));
476 /* copy next element's data to our pad */
477 memcpy(hide_end, next, sizeof(*hide_end));
479 /* pad next element */
480 next->state = ELEM_PAD;
481 next->pad = len_after;
482 next->size -= len_after;
484 /* next element busy, would've been merged otherwise */
485 hide_end->pad = len_after;
486 hide_end->size += len_after;
488 /* adjust pointers to point to our new pad */
490 next->next->prev = hide_end;
491 elem->next = hide_end;
492 } else if (len_after > 0) {
493 RTE_LOG(ERR, EAL, "Unaligned element, heap is probably corrupt\n");
498 /* we cannot do anything with non-adjacent elements */
499 if (prev && prev_elem_is_adjacent(elem)) {
500 len_before = RTE_PTR_DIFF(hide_start, elem);
501 if (len_before >= MALLOC_ELEM_OVERHEAD + MIN_DATA_SIZE) {
503 split_elem(elem, hide_start);
508 malloc_elem_free_list_insert(prev);
509 } else if (len_before > 0) {
511 * unlike with elements after current, here we don't
512 * need to pad elements, but rather just increase the
513 * size of previous element, copy the old header and set
516 void *trailer = RTE_PTR_ADD(prev,
517 prev->size - MALLOC_ELEM_TRAILER_LEN);
519 memcpy(hide_start, elem, sizeof(*elem));
520 hide_start->size = len;
522 prev->size += len_before;
525 /* update pointers */
526 prev->next = hide_start;
528 next->prev = hide_start;
530 /* erase old trailer */
531 memset(trailer, 0, MALLOC_ELEM_TRAILER_LEN);
532 /* erase old header */
533 memset(elem, 0, sizeof(*elem));
543 * attempt to resize a malloc_elem by expanding into any free space
544 * immediately after it in memory.
547 malloc_elem_resize(struct malloc_elem *elem, size_t size)
549 const size_t new_size = size + elem->pad + MALLOC_ELEM_OVERHEAD;
551 /* if we request a smaller size, then always return ok */
552 if (elem->size >= new_size)
555 /* check if there is a next element, it's free and adjacent */
556 if (!elem->next || elem->next->state != ELEM_FREE ||
557 !next_elem_is_adjacent(elem))
559 if (elem->size + elem->next->size < new_size)
562 /* we now know the element fits, so remove from free list,
565 malloc_elem_free_list_remove(elem->next);
566 join_elem(elem, elem->next);
568 if (elem->size - new_size >= MIN_DATA_SIZE + MALLOC_ELEM_OVERHEAD) {
569 /* now we have a big block together. Lets cut it down a bit, by splitting */
570 struct malloc_elem *split_pt = RTE_PTR_ADD(elem, new_size);
571 split_pt = RTE_PTR_ALIGN_CEIL(split_pt, RTE_CACHE_LINE_SIZE);
572 split_elem(elem, split_pt);
573 malloc_elem_free_list_insert(split_pt);
578 static inline const char *
579 elem_state_to_str(enum elem_state state)
593 malloc_elem_dump(const struct malloc_elem *elem, FILE *f)
595 fprintf(f, "Malloc element at %p (%s)\n", elem,
596 elem_state_to_str(elem->state));
597 fprintf(f, " len: 0x%zx pad: 0x%" PRIx32 "\n", elem->size, elem->pad);
598 fprintf(f, " prev: %p next: %p\n", elem->prev, elem->next);