1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
/*
* Copyright (C) 2023-2025 Colin Ian King.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include "stress-ng.h"
#include "core-lock.h"
#include "core-madvise.h"
#include "core-stressors.h"
#include "core-shared-heap.h"
/*
* The max heap size needs to be larger if we can't determine if strings
* being dup'd are literal strings. Literal string dups just use the
* literal string, non-literals (e.g. stack based) need to be dup'd from
* a shared memory heap.
*/
#if defined(HAVE_BUILTIN_CONSTANT_P)
#define STRESS_MAX_SHARED_HEAP_SIZE (64 * KB)
#else
#define STRESS_MAX_SHARED_HEAP_SIZE (256 * KB)
#endif
/* Used just to determine number of stressors via STRESS_MAX */
enum {
STRESSORS(STRESSOR_ENUM)
STRESS_MAX
};
typedef struct stress_shared_heap_str {
struct stress_shared_heap_str *next;
char str[];
} stress_shared_heap_str_t;
/*
* stress_shared_heap_init()
* initialized shared heap
*/
void *stress_shared_heap_init(void)
{
const size_t page_size = stress_get_page_size();
/* Allocate enough heap for all stressor descriptions with 100% metrics allocated */
size_t size = (STRESS_MISC_METRICS_MAX * (32 + sizeof(void *)) * STRESS_MAX);
size = STRESS_MINIMUM(size, STRESS_MAX_SHARED_HEAP_SIZE);
g_shared->shared_heap.out_of_memory = false;
g_shared->shared_heap.heap_size = (size + page_size - 1) & ~(page_size - 1);
g_shared->shared_heap.str_list_head = NULL;
g_shared->shared_heap.heap = stress_mmap_populate(NULL, size,
PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_SHARED, -1, 0);
if (UNLIKELY(g_shared->shared_heap.heap == MAP_FAILED)) {
g_shared->shared_heap.lock = NULL;
return NULL;
}
stress_set_vma_anon_name(g_shared->shared_heap.heap, size, "shared-heap");
(void)stress_madvise_mergeable(g_shared->shared_heap.heap, size);
g_shared->shared_heap.lock = stress_lock_create("shared-heap");
if (UNLIKELY(!g_shared->shared_heap.lock)) {
(void)munmap((void *)g_shared->shared_heap.heap, g_shared->shared_heap.heap_size);
g_shared->shared_heap.heap = NULL;
return NULL;
}
return g_shared->shared_heap.lock;
}
/*
* stress_shared_heap_free()
* free shared heap
*/
void stress_shared_heap_free(void)
{
if (g_shared->shared_heap.out_of_memory) {
pr_inf("shared heap: out of memory duplicating some strings, increase STRESS_MAX_SHARED_HEAP_SIZE to fix this\n");
}
#if defined(STRESS_SHARED_HEAD_DEBUG)
if (g_shared->shared_heap.offset > 0) {
pr_dbg("shared heap: used %zd of %zd bytes of heap\n", g_shared->shared_heap.offset, g_shared->shared_heap.heap_size);
}
#endif
if (g_shared->shared_heap.heap) {
(void)munmap((void *)g_shared->shared_heap.heap, g_shared->shared_heap.heap_size);
g_shared->shared_heap.heap = NULL;
}
if (g_shared->shared_heap.lock) {
(void)stress_lock_destroy(g_shared->shared_heap.lock);
g_shared->shared_heap.lock = NULL;
}
g_shared->shared_heap.out_of_memory = false;
}
/*
* stress_shared_heap_malloc()
* Primitive non-free'ing heap allocator. Just return next allocated chunk from
* the shared memory heap. We don't use need a per-object free'ing, so no need
* to keep track of holes or do hole coalescing. Keep it simple for now.
*/
void *stress_shared_heap_malloc(const size_t size)
{
ssize_t heap_free;
void *ptr;
if (UNLIKELY(stress_lock_acquire(g_shared->shared_heap.lock) < 0))
return NULL;
heap_free = g_shared->shared_heap.heap_size - g_shared->shared_heap.offset;
if (heap_free < (ssize_t)size) {
g_shared->shared_heap.out_of_memory = true;
(void)stress_lock_release(g_shared->shared_heap.lock);
return NULL;
}
ptr = (void *)((uintptr_t)g_shared->shared_heap.heap + g_shared->shared_heap.offset);
g_shared->shared_heap.offset += (size + sizeof(void *) - 1) & ~(sizeof(void *) - 1);
(void)stress_lock_release(g_shared->shared_heap.lock);
return ptr;
}
/*
* stress_shared_heap_dup_const()
* Do a strdup of string using the shared heap. String must never be
* modified as this dup operation re-used existing identical strings
* allocated on the shared heap. This is designed for storing metric
* descriptions that get allocated per stressor and we want to reduce
* duplicated allocations where possible.
*/
char *stress_shared_heap_dup_const(const char *str)
{
size_t len, str_len;
stress_shared_heap_str_t *heap_str;
if (UNLIKELY(stress_lock_acquire(g_shared->shared_heap.lock) < 0))
return NULL;
for (heap_str = (stress_shared_heap_str_t *)g_shared->shared_heap.str_list_head; heap_str; heap_str = heap_str->next) {
if (strcmp(str, heap_str->str) == 0) {
(void)stress_lock_release(g_shared->shared_heap.lock);
return heap_str->str;
}
}
(void)stress_lock_release(g_shared->shared_heap.lock);
str_len = strlen(str) + 1;
len = str_len + sizeof(void *);
heap_str = (stress_shared_heap_str_t *)stress_shared_heap_malloc(len);
if (UNLIKELY(!heap_str))
return NULL;
(void)shim_strscpy(heap_str->str, str, str_len);
heap_str->next = NULL;
/*
* We failed to acquire so we can't add to list, return dup'd string
* and skip adding it to the list, at least the dup worked!
*/
if (UNLIKELY(stress_lock_acquire(g_shared->shared_heap.lock) < 0))
return heap_str->str;
/*
* Save a copy so it can be re-used
*/
heap_str->next = (stress_shared_heap_str_t *)g_shared->shared_heap.str_list_head;
g_shared->shared_heap.str_list_head = (void *)heap_str;
(void)stress_lock_release(g_shared->shared_heap.lock);
return heap_str->str;
}
|
