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
|
/*
* netsniff-ng - the packet sniffing beast
* Copyright 2011 Daniel Borkmann.
* Subject to the GPL, version 2.
*/
#define _GNU_SOURCE
#include <search.h>
#include <limits.h>
#include <errno.h>
#include <string.h>
#include "locking.h"
#include "cpusched.h"
#include "xmalloc.h"
#include "hash.h"
struct map_entry {
int fd;
unsigned int cpu;
struct map_entry *next;
};
static struct hash_table mapper;
static unsigned int *cpu_assigned = NULL;
static unsigned int cpu_len = 0;
static struct rwlock map_lock;
void init_cpusched(unsigned int cpus)
{
rwlock_init(&map_lock);
rwlock_wr_lock(&map_lock);
cpu_len = cpus;
cpu_assigned = xzmalloc(cpus * sizeof(*cpu_assigned));
memset(&mapper, 0, sizeof(mapper));
init_hash(&mapper);
rwlock_unlock(&map_lock);
}
static int get_appropriate_cpu(void)
{
int i, cpu = 0;
int work = INT_MAX;
for (i = 0; i < cpu_len; ++i) {
if (cpu_assigned[i] < work) {
work = cpu_assigned[i];
cpu = i;
}
}
return cpu;
}
unsigned int socket_to_cpu(int fd)
{
int cpu = 0;
struct map_entry *entry;
errno = 0;
rwlock_rd_lock(&map_lock);
entry = lookup_hash(fd, &mapper);
while (entry && fd != entry->fd)
entry = entry->next;
if (entry && fd == entry->fd)
cpu = entry->cpu;
else
errno = ENOENT;
rwlock_unlock(&map_lock);
return cpu;
}
unsigned int register_socket(int fd)
{
void **pos;
struct map_entry *entry;
rwlock_wr_lock(&map_lock);
entry = xzmalloc(sizeof(*entry));
entry->fd = fd;
entry->cpu = get_appropriate_cpu();
cpu_assigned[entry->cpu]++;
pos = insert_hash(entry->fd, entry, &mapper);
if (pos) {
entry->next = (*pos);
(*pos) = entry;
}
rwlock_unlock(&map_lock);
return entry->cpu;
}
static struct map_entry *socket_to_map_entry(int fd)
{
struct map_entry *entry, *ret = NULL;
errno = 0;
rwlock_rd_lock(&map_lock);
entry = lookup_hash(fd, &mapper);
while (entry && fd != entry->fd)
entry = entry->next;
if (entry && fd == entry->fd)
ret = entry;
else
errno = ENOENT;
rwlock_unlock(&map_lock);
return ret;
}
void unregister_socket(int fd)
{
struct map_entry *pos;
struct map_entry *entry = socket_to_map_entry(fd);
if (!entry == 0 && errno == ENOENT)
return;
rwlock_wr_lock(&map_lock);
cpu_assigned[entry->cpu]--;
pos = remove_hash(entry->fd, entry, entry->next, &mapper);
while (pos && pos->next && pos->next != entry)
pos = pos->next;
if (pos && pos->next && pos->next == entry)
pos->next = entry->next;
entry->next = NULL;
xfree(entry);
rwlock_unlock(&map_lock);
}
static int cleanup_batch(void *ptr)
{
struct map_entry *next;
struct map_entry *e = ptr;
if (!e)
return 0;
while ((next = e->next)) {
e->next = NULL;
xfree(e);
e = next;
}
xfree(e);
return 0;
}
void destroy_cpusched(void)
{
rwlock_wr_lock(&map_lock);
xfree(cpu_assigned);
cpu_len = 0;
for_each_hash(&mapper, cleanup_batch);
free_hash(&mapper);
rwlock_unlock(&map_lock);
rwlock_destroy(&map_lock);
}
|
