4 * Copyright(c) 2010-2012 Intel Corporation. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * * Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * * Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
17 * * Neither the name of Intel Corporation nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37 #include <sys/queue.h>
39 #include <rte_memory.h>
40 #include <rte_memzone.h>
41 #include <rte_tailq.h>
43 #include <rte_launch.h>
44 #include <rte_per_lcore.h>
45 #include <rte_lcore.h>
46 #include <rte_debug.h>
47 #include <rte_common.h>
48 #include <rte_spinlock.h>
50 #include "malloc_elem.h"
51 #include "malloc_heap.h"
53 #define MIN_DATA_SIZE (CACHE_LINE_SIZE * 2)
56 * initialise a general malloc_elem header structure
59 malloc_elem_init(struct malloc_elem *elem,
60 struct malloc_heap *heap, size_t size)
63 elem->prev = elem->next_free = NULL;
64 elem->state = ELEM_FREE;
72 * initialise a dummy malloc_elem header for the end-of-memzone marker
75 malloc_elem_mkend(struct malloc_elem *elem, struct malloc_elem *prev)
77 malloc_elem_init(elem, prev->heap, 0);
79 elem->state = ELEM_BUSY; /* mark busy so its never merged */
83 * calculate the starting point of where data of the requested size
84 * and alignment would fit in the current element. If the data doesn't
88 elem_start_pt(struct malloc_elem *elem, size_t size, unsigned align)
90 const uintptr_t end_pt = (uintptr_t)elem +
91 elem->size - MALLOC_ELEM_TRAILER_LEN;
92 const uintptr_t new_data_start = rte_align_floor_int((end_pt - size),align);
93 const uintptr_t new_elem_start = new_data_start - MALLOC_ELEM_HEADER_LEN;
95 /* if the new start point is before the exist start, it won't fit */
96 return (new_elem_start < (uintptr_t)elem) ? NULL : (void *)new_elem_start;
100 * use elem_start_pt to determine if we get meet the size and
101 * alignment request from the current element
104 malloc_elem_can_hold(struct malloc_elem *elem, size_t size, unsigned align)
106 return elem_start_pt(elem, size, align) != NULL;
110 * split an existing element into two smaller elements at the given
111 * split_pt parameter.
114 split_elem(struct malloc_elem *elem, struct malloc_elem *split_pt)
116 struct malloc_elem *next_elem = RTE_PTR_ADD(elem, elem->size);
117 const unsigned old_elem_size = (uintptr_t)split_pt - (uintptr_t)elem;
118 const unsigned new_elem_size = elem->size - old_elem_size;
120 malloc_elem_init(split_pt, elem->heap, new_elem_size);
121 split_pt->prev = elem;
122 next_elem->prev = split_pt;
123 elem->size = old_elem_size;
128 * reserve a block of data in an existing malloc_elem. If the malloc_elem
129 * is much larger than the data block requested, we split the element in two.
130 * This function is only called from malloc_heap_alloc so parameter checking
131 * is not done here, as it's done there previously.
134 malloc_elem_alloc(struct malloc_elem *elem, size_t size,
135 unsigned align, struct malloc_elem *prev_free)
137 struct malloc_elem *new_elem = elem_start_pt(elem, size, align);
138 const unsigned old_elem_size = (uintptr_t)new_elem - (uintptr_t)elem;
140 if (old_elem_size <= MALLOC_ELEM_OVERHEAD + MIN_DATA_SIZE){
141 /* don't split it, pad the element instead */
142 elem->state = ELEM_BUSY;
143 elem->pad = old_elem_size;
145 /* put a dummy header in padding, to point to real element header */
146 if (elem->pad > 0){ /* pad will be at least 64-bytes, as everything
147 * is cache-line aligned */
148 new_elem->pad = elem->pad;
149 new_elem->state = ELEM_PAD;
150 new_elem->size = elem->size - elem->pad;
151 set_header(new_elem);
153 /* remove element from free list */
154 if (prev_free == NULL)
155 elem->heap->free_head = elem->next_free;
157 prev_free->next_free = elem->next_free;
162 /* we are going to split the element in two. The original element
163 * remains free, and the new element is the one allocated, so no free list
164 * changes need to be made.
166 split_elem(elem, new_elem);
167 new_elem->state = ELEM_BUSY;
173 * joing two struct malloc_elem together. elem1 and elem2 must
174 * be contiguous in memory.
177 join_elem(struct malloc_elem *elem1, struct malloc_elem *elem2)
179 struct malloc_elem *next = RTE_PTR_ADD(elem2, elem2->size);
180 elem1->size += elem2->size;
185 * scan the free list, and remove the request element from that
186 * free list. (Free list to scan is got from heap pointer in element)
189 remove_from_free_list(struct malloc_elem *elem)
191 if (elem == elem->heap->free_head)
192 elem->heap->free_head = elem->next_free;
194 struct malloc_elem *prev_free = elem->heap->free_head;
195 while (prev_free && prev_free->next_free != elem)
196 prev_free = prev_free->next_free;
198 rte_panic("Corrupted free list\n");
199 prev_free->next_free = elem->next_free;
204 * free a malloc_elem block by adding it to the free list. If the
205 * blocks either immediately before or immediately after newly freed block
206 * are also free, the blocks are merged together.
209 malloc_elem_free(struct malloc_elem *elem)
211 if (!malloc_elem_cookies_ok(elem) || elem->state != ELEM_BUSY)
214 rte_spinlock_lock(&(elem->heap->lock));
215 struct malloc_elem *next = RTE_PTR_ADD(elem, elem->size);
216 if (next->state == ELEM_FREE){
217 /* join to this one, and remove from free list */
218 join_elem(elem, next);
219 remove_from_free_list(next);
222 /* check if previous element is free, if so join with it and return,
223 * no need to update free list, as that element is already there
225 if (elem->prev != NULL && elem->prev->state == ELEM_FREE)
226 join_elem(elem->prev, elem);
227 /* otherwise add ourselves to the free list */
229 elem->next_free = elem->heap->free_head;
230 elem->heap->free_head = elem;
231 elem->state = ELEM_FREE;
234 /* decrease heap's count of allocated elements */
235 elem->heap->alloc_count--;
236 rte_spinlock_unlock(&(elem->heap->lock));
242 * attempt to resize a malloc_elem by expanding into any free space
243 * immediately after it in memory.
246 malloc_elem_resize(struct malloc_elem *elem, size_t size)
248 const size_t new_size = size + MALLOC_ELEM_OVERHEAD;
249 /* if we request a smaller size, then always return ok */
250 const size_t current_size = elem->size - elem->pad;
251 if (current_size >= new_size)
254 struct malloc_elem *next = RTE_PTR_ADD(elem, elem->size);
255 rte_spinlock_lock(&elem->heap->lock);
256 if (next ->state != ELEM_FREE)
258 if (current_size + next->size < new_size)
261 /* we now know the element fits, so join the two, then remove from free
264 join_elem(elem, next);
265 remove_from_free_list(next);
267 if (elem->size - new_size > MIN_DATA_SIZE + MALLOC_ELEM_OVERHEAD){
268 /* now we have a big block together. Lets cut it down a bit, by splitting */
269 struct malloc_elem *split_pt = RTE_PTR_ADD(elem, new_size);
270 split_pt = RTE_PTR_ALIGN_CEIL(split_pt, CACHE_LINE_SIZE);
271 split_elem(elem, split_pt);
272 split_pt->state = ELEM_FREE;
273 split_pt->next_free = elem->heap->free_head;
274 elem->heap->free_head = split_pt;
276 rte_spinlock_unlock(&elem->heap->lock);
280 rte_spinlock_unlock(&elem->heap->lock);