taskset: rewrite to be task size-agnostic
function old new delta packed_usage 31130 31190 +60 taskset_main 623 525 -98 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 1/1 up/down: 60/-98) Total: -38 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
parent
205d48e948
commit
ef0e76cc27
@ -8,7 +8,7 @@
|
||||
|
||||
//config:config TASKSET
|
||||
//config: bool "taskset"
|
||||
//config: default n # doesn't build on some non-x86 targets (m68k)
|
||||
//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.
|
||||
@ -18,15 +18,15 @@
|
||||
//config: default y
|
||||
//config: depends on TASKSET
|
||||
//config: help
|
||||
//config: Add code for fancy output. This merely silences a compiler-warning
|
||||
//config: and adds about 135 Bytes. May be needed for machines with alot
|
||||
//config: of CPUs.
|
||||
//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(taskset, BB_DIR_USR_BIN, BB_SUID_DROP))
|
||||
//kbuild:lib-$(CONFIG_TASKSET) += taskset.o
|
||||
|
||||
//usage:#define taskset_trivial_usage
|
||||
//usage: "[-p] [MASK] [PID | PROG ARGS]"
|
||||
//usage: "[-p] [HEXMASK] [PID | PROG ARGS]"
|
||||
//usage:#define taskset_full_usage "\n\n"
|
||||
//usage: "Set or get CPU affinity\n"
|
||||
//usage: "\n -p Operate on an existing PID"
|
||||
@ -42,71 +42,80 @@
|
||||
//usage: "$ taskset -p 1\n"
|
||||
//usage: "pid 1's current affinity mask: 3\n"
|
||||
/*
|
||||
Not yet implemented:
|
||||
* 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_cpuset(cpu_set_t *mask)
|
||||
static char *from_mask(const ul *mask, unsigned sz_in_bytes)
|
||||
{
|
||||
int i;
|
||||
char *ret = NULL;
|
||||
char *str = xzalloc((CPU_SETSIZE / 4) + 1); /* we will leak it */
|
||||
|
||||
for (i = CPU_SETSIZE - 4; i >= 0; i -= 4) {
|
||||
int val = 0;
|
||||
int off;
|
||||
for (off = 0; off <= 3; ++off)
|
||||
if (CPU_ISSET(i + off, mask))
|
||||
val |= 1 << off;
|
||||
if (!ret && val)
|
||||
ret = str;
|
||||
*str++ = bb_hexdigits_upcase[val] | 0x20;
|
||||
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;
|
||||
}
|
||||
return ret;
|
||||
while (str[0] == '0' && str[1])
|
||||
str++;
|
||||
return str;
|
||||
}
|
||||
#else
|
||||
#define TASKSET_PRINTF_MASK "%llx"
|
||||
static unsigned long long from_cpuset(cpu_set_t *mask)
|
||||
#define TASKSET_PRINTF_MASK "%lx"
|
||||
static unsigned long long from_mask(ul *mask, unsigned sz_in_bytes UNUSED_PARAM)
|
||||
{
|
||||
BUILD_BUG_ON(CPU_SETSIZE < 8*sizeof(int));
|
||||
|
||||
/* Take the least significant bits. Assume cpu_set_t is
|
||||
* implemented as an array of unsigned long or unsigned
|
||||
* int.
|
||||
*/
|
||||
if (CPU_SETSIZE < 8*sizeof(long))
|
||||
return *(unsigned*)mask;
|
||||
if (CPU_SETSIZE < 8*sizeof(long long))
|
||||
return *(unsigned long*)mask;
|
||||
# if BB_BIG_ENDIAN
|
||||
if (sizeof(long long) > sizeof(long)) {
|
||||
/* We can put two long in the long long, but they have to
|
||||
* be swapped: the least significant word comes first in the
|
||||
* array */
|
||||
unsigned long *p = (void*)mask;
|
||||
return p[0] + ((unsigned long long)p[1] << (8*sizeof(long)));
|
||||
}
|
||||
# endif
|
||||
return *(unsigned long long*)mask;
|
||||
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)
|
||||
{
|
||||
cpu_set_t mask;
|
||||
ul *mask;
|
||||
unsigned mask_size_in_bytes;
|
||||
pid_t pid = 0;
|
||||
unsigned opt_p;
|
||||
const char *current_new;
|
||||
char *pid_str;
|
||||
char *aff = aff; /* for compiler */
|
||||
|
||||
/* NB: we mimic util-linux's taskset: -p does not take
|
||||
@ -119,7 +128,7 @@ int taskset_main(int argc UNUSED_PARAM, char **argv)
|
||||
argv += optind;
|
||||
|
||||
if (opt_p) {
|
||||
pid_str = *argv++;
|
||||
char *pid_str = *argv++;
|
||||
if (*argv) { /* "-p <aff> <pid> ...rest.is.ignored..." */
|
||||
aff = pid_str;
|
||||
pid_str = *argv; /* NB: *argv != NULL in this case */
|
||||
@ -132,13 +141,14 @@ int taskset_main(int argc UNUSED_PARAM, char **argv)
|
||||
bb_show_usage();
|
||||
}
|
||||
|
||||
mask_size_in_bytes = SZOF_UL;
|
||||
mask = NULL;
|
||||
current_new = "current\0new";
|
||||
if (opt_p) {
|
||||
print_aff:
|
||||
if (sched_getaffinity(pid, sizeof(mask), &mask) < 0)
|
||||
bb_perror_msg_and_die("can't %cet pid %d's affinity", 'g', pid);
|
||||
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_cpuset(&mask));
|
||||
pid, current_new, from_mask(mask, mask_size_in_bytes));
|
||||
if (!*argv) {
|
||||
/* Either it was just "-p <pid>",
|
||||
* or it was "-p <aff> <pid>" and we came here
|
||||
@ -148,72 +158,63 @@ int taskset_main(int argc UNUSED_PARAM, char **argv)
|
||||
*argv = NULL;
|
||||
current_new += 8; /* "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;
|
||||
|
||||
/* Affinity was specified, translate it into cpu_set_t */
|
||||
CPU_ZERO(&mask);
|
||||
if (!ENABLE_FEATURE_TASKSET_FANCY) {
|
||||
unsigned i;
|
||||
unsigned long long m;
|
||||
|
||||
/* Do not allow zero mask: */
|
||||
m = xstrtoull_range(aff, 0, 1, ULLONG_MAX);
|
||||
i = 0;
|
||||
do {
|
||||
if (m & 1)
|
||||
CPU_SET(i, &mask);
|
||||
i++;
|
||||
m >>= 1;
|
||||
} while (m != 0);
|
||||
mask[0] = xstrtoul_range(aff, 16, 1, ULONG_MAX);
|
||||
} else {
|
||||
unsigned i;
|
||||
char *last_byte;
|
||||
char *bin;
|
||||
uint8_t bit_in_byte;
|
||||
char *last_char;
|
||||
|
||||
/* Cheap way to get "long enough" buffer */
|
||||
bin = xstrdup(aff);
|
||||
i = 0; /* bit pos in mask[] */
|
||||
|
||||
if (aff[0] != '0' || (aff[1]|0x20) != 'x') {
|
||||
/* TODO: decimal/octal masks are still limited to 2^64 */
|
||||
unsigned long long m = xstrtoull_range(aff, 0, 1, ULLONG_MAX);
|
||||
bin += strlen(bin);
|
||||
last_byte = bin - 1;
|
||||
while (m) {
|
||||
*--bin = m & 0xff;
|
||||
m >>= 8;
|
||||
}
|
||||
} else {
|
||||
/* aff is "0x.....", we accept very long masks in this form */
|
||||
last_byte = hex2bin(bin, aff + 2, INT_MAX);
|
||||
if (!last_byte) {
|
||||
bad_aff:
|
||||
/* 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);
|
||||
}
|
||||
last_byte--; /* now points to the last byte */
|
||||
}
|
||||
|
||||
i = 0;
|
||||
bit_in_byte = 1;
|
||||
while (last_byte >= bin) {
|
||||
if (bit_in_byte & *last_byte) {
|
||||
if (i >= CPU_SETSIZE)
|
||||
goto bad_aff;
|
||||
CPU_SET(i, &mask);
|
||||
if (i < mask_size_in_bytes * 8) {
|
||||
mask[i / BITS_UL] |= val << (i & MASK_UL);
|
||||
//bb_error_msg("bit %d set", i);
|
||||
}
|
||||
i++;
|
||||
/* bit_in_byte is uint8_t! & 0xff is implied */
|
||||
bit_in_byte = (bit_in_byte << 1);
|
||||
if (!bit_in_byte) {
|
||||
bit_in_byte = 1;
|
||||
last_byte--;
|
||||
}
|
||||
/* 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,
|
||||
* 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, sizeof(mask), &mask))
|
||||
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 */
|
||||
|
||||
Loading…
Reference in New Issue
Block a user