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
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
|
/* vi: set sw=4 ts=4: */
/*
* taskset - retrieve or set a processes' CPU affinity
* Copyright (c) 2006 Bernhard Reutner-Fischer
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//config:config TASKSET
//config: bool "taskset (4.1 kb)"
//config: default y
//config: help
//config: Retrieve or set a processes's CPU affinity.
//config: This requires sched_{g,s}etaffinity support in your libc.
//config:
//config:config FEATURE_TASKSET_FANCY
//config: bool "Fancy output"
//config: default y
//config: depends on TASKSET
//config: help
//config: Needed for machines with more than 32-64 CPUs:
//config: affinity parameter 0xHHHHHHHHHHHHHHHHHHHH can be arbitrarily long
//config: in this case. Otherwise, it is limited to sizeof(long).
//applet:IF_TASKSET(APPLET_NOEXEC(taskset, taskset, BB_DIR_USR_BIN, BB_SUID_DROP, taskset))
//kbuild:lib-$(CONFIG_TASKSET) += taskset.o
//usage:#define taskset_trivial_usage
//usage: "[-p] [HEXMASK] PID | PROG ARGS"
//usage:#define taskset_full_usage "\n\n"
//usage: "Set or get CPU affinity\n"
//usage: "\n -p Operate on an existing PID"
//usage:
//usage:#define taskset_example_usage
//usage: "$ taskset 0x7 ./dgemm_test&\n"
//usage: "$ taskset -p 0x1 $!\n"
//usage: "pid 4790's current affinity mask: 7\n"
//usage: "pid 4790's new affinity mask: 1\n"
//usage: "$ taskset 0x7 /bin/sh -c './taskset -p 0x1 $$'\n"
//usage: "pid 6671's current affinity mask: 1\n"
//usage: "pid 6671's new affinity mask: 1\n"
//usage: "$ taskset -p 1\n"
//usage: "pid 1's current affinity mask: 3\n"
/*
* Not yet implemented:
* -a/--all-tasks (affect all threads)
* needs to get TIDs from /proc/PID/task/ and use _them_ as "pid" in sched_setaffinity(pid)
* -c/--cpu-list (specify CPUs via "1,3,5-7")
*/
#include <sched.h>
#include "libbb.h"
typedef unsigned long ul;
#define SZOF_UL (unsigned)(sizeof(ul))
#define BITS_UL (unsigned)(sizeof(ul)*8)
#define MASK_UL (unsigned)(sizeof(ul)*8 - 1)
#if ENABLE_FEATURE_TASKSET_FANCY
#define TASKSET_PRINTF_MASK "%s"
/* craft a string from the mask */
static char *from_mask(const ul *mask, unsigned sz_in_bytes)
{
char *str = xzalloc((sz_in_bytes+1) * 2); /* we will leak it */
char *p = str;
for (;;) {
ul v = *mask++;
if (SZOF_UL == 4)
p += sprintf(p, "%08lx", v);
if (SZOF_UL == 8)
p += sprintf(p, "%016lx", v);
if (SZOF_UL == 16)
p += sprintf(p, "%032lx", v); /* :) */
sz_in_bytes -= SZOF_UL;
if ((int)sz_in_bytes <= 0)
break;
}
while (str[0] == '0' && str[1])
str++;
return str;
}
#else
#define TASKSET_PRINTF_MASK "%lx"
static unsigned long long from_mask(ul *mask, unsigned sz_in_bytes UNUSED_PARAM)
{
return *mask;
}
#endif
static unsigned long *get_aff(int pid, unsigned *sz)
{
int r;
unsigned long *mask = NULL;
unsigned sz_in_bytes = *sz;
for (;;) {
mask = xrealloc(mask, sz_in_bytes);
r = sched_getaffinity(pid, sz_in_bytes, (void*)mask);
if (r == 0)
break;
sz_in_bytes *= 2;
if (errno == EINVAL && (int)sz_in_bytes > 0)
continue;
bb_perror_msg_and_die("can't %cet pid %d's affinity", 'g', pid);
}
//bb_error_msg("get mask[0]:%lx sz_in_bytes:%d", mask[0], sz_in_bytes);
*sz = sz_in_bytes;
return mask;
}
int taskset_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int taskset_main(int argc UNUSED_PARAM, char **argv)
{
ul *mask;
unsigned mask_size_in_bytes;
pid_t pid = 0;
unsigned opt_p;
const char *current_new;
char *aff;
/* NB: we mimic util-linux's taskset: -p does not take
* an argument, i.e., "-pN" is NOT valid, only "-p N"!
* Indeed, util-linux-2.13-pre7 uses:
* getopt_long(argc, argv, "+pchV", ...), not "...p:..." */
opt_p = getopt32(argv, "^+" "p" "\0" "-1" /* at least 1 arg */);
argv += optind;
aff = *argv++;
if (opt_p) {
char *pid_str = aff;
if (*argv) { /* "-p <aff> <pid> ...rest.is.ignored..." */
pid_str = *argv; /* NB: *argv != NULL in this case */
}
/* else it was just "-p <pid>", and *argv == NULL */
pid = xatoul_range(pid_str, 1, ((unsigned)(pid_t)ULONG_MAX) >> 1);
} else {
/* <aff> <cmd...> */
if (!*argv)
bb_show_usage();
}
mask_size_in_bytes = SZOF_UL;
current_new = "current";
print_aff:
mask = get_aff(pid, &mask_size_in_bytes);
if (opt_p) {
printf("pid %d's %s affinity mask: "TASKSET_PRINTF_MASK"\n",
pid, current_new, from_mask(mask, mask_size_in_bytes));
if (*argv == NULL) {
/* Either it was just "-p <pid>",
* or it was "-p <aff> <pid>" and we came here
* for the second time (see goto below) */
return EXIT_SUCCESS;
}
*argv = NULL;
current_new = "new";
}
memset(mask, 0, mask_size_in_bytes);
/* Affinity was specified, translate it into mask */
/* it is always in hex, skip "0x" if it exists */
if (aff[0] == '0' && (aff[1]|0x20) == 'x')
aff += 2;
if (!ENABLE_FEATURE_TASKSET_FANCY) {
mask[0] = xstrtoul(aff, 16);
} else {
unsigned i;
char *last_char;
i = 0; /* bit pos in mask[] */
/* aff is ASCII hex string, accept very long masks in this form.
* Process hex string AABBCCDD... to ulong mask[]
* from the rightmost nibble, which is least-significant.
* Bits not fitting into mask[] are ignored: (example: 1234
* in 12340000000000000000000000000000000000000ff)
*/
last_char = strchrnul(aff, '\0');
while (last_char > aff) {
char c;
ul val;
last_char--;
c = *last_char;
if (isdigit(c))
val = c - '0';
else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
val = (c|0x20) - ('a' - 10);
else
bb_error_msg_and_die("bad affinity '%s'", aff);
if (i < mask_size_in_bytes * 8) {
mask[i / BITS_UL] |= val << (i & MASK_UL);
//bb_error_msg("bit %d set", i);
}
/* else:
* We can error out here, but we don't.
* For one, kernel itself ignores bits in mask[]
* which do not map to any CPUs:
* if mask[] has one 32-bit long element,
* but you have only 8 CPUs, all bits beyond first 8
* are ignored, silently.
* No point in making bits past 31th to be errors.
*/
i += 4;
}
}
/* Set pid's or our own (pid==0) affinity */
if (sched_setaffinity(pid, mask_size_in_bytes, (void*)mask))
bb_perror_msg_and_die("can't %cet pid %d's affinity", 's', pid);
//bb_error_msg("set mask[0]:%lx", mask[0]);
if (!argv[0]) /* "-p <aff> <pid> [...ignored...]" */
goto print_aff; /* print new affinity and exit */
BB_EXECVP_or_die(argv);
}
|
