taskset: implement -a

function                                             old     new   delta
process_pid_str                                        -     854    +854
.rodata                                           103363  103378     +15
packed_usage                                       33654   33658      +4
taskset_main                                         936     190    -746
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/1 up/down: 873/-746)          Total: 127 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2021-06-19 17:42:35 +02:00
parent 97c3b5e3ff
commit 25128176c4

View File

@ -34,10 +34,12 @@
//kbuild:lib-$(CONFIG_TASKSET) += taskset.o
//usage:#define taskset_trivial_usage
//usage: "[-p] [HEXMASK] PID | PROG ARGS"
//usage: "[-ap] [HEXMASK"IF_FEATURE_TASKSET_CPULIST(" | -c LIST")"] { PID | PROG ARGS }"
//usage:#define taskset_full_usage "\n\n"
//usage: "Set or get CPU affinity\n"
//usage: "\n -p Operate on an existing PID"
//usage: "\n -p Operate on PID"
//usage: "\n -a Operate on all threads"
//usage: "\n -c Affinity is a list, not mask"
//usage:
//usage:#define taskset_example_usage
//usage: "$ taskset 0x7 ./dgemm_test&\n"
@ -205,42 +207,18 @@ static void print_cpulist(const ul *mask, unsigned mask_size_in_bytes)
}
#endif
int taskset_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int taskset_main(int argc UNUSED_PARAM, char **argv)
enum {
OPT_p = 1 << 0,
OPT_a = 1 << 1,
OPT_c = (1 << 2) * ENABLE_FEATURE_TASKSET_CPULIST,
};
static void process_pid_str(const char *pid_str, unsigned opts, char *aff)
{
ul *mask;
unsigned mask_size_in_bytes;
pid_t pid = 0;
const char *current_new;
char *aff;
unsigned opts;
enum {
OPT_p = 1 << 0,
OPT_c = (1 << 1) * ENABLE_FEATURE_TASKSET_CPULIST,
};
/* 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:..." */
opts = getopt32(argv, "^+" "p"IF_FEATURE_TASKSET_CPULIST("c")
"\0" "-1" /* at least 1 arg */);
argv += optind;
aff = *argv++;
if (opts & 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();
}
pid_t pid = xatoi_positive(pid_str);
mask_size_in_bytes = SZOF_UL;
current_new = "current";
@ -255,13 +233,12 @@ int taskset_main(int argc UNUSED_PARAM, char **argv)
#endif
printf("pid %d's %s affinity mask: "TASKSET_PRINTF_MASK"\n",
pid, current_new, from_mask(mask, mask_size_in_bytes));
if (*argv == NULL) {
if (!aff) {
/* 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;
return;
}
*argv = NULL;
current_new = "new";
}
memset(mask, 0, mask_size_in_bytes);
@ -331,8 +308,61 @@ int taskset_main(int argc UNUSED_PARAM, char **argv)
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...]" */
if ((opts & OPT_p) && aff) { /* "-p <aff> <pid> [...ignored...]" */
aff = NULL;
goto print_aff; /* print new affinity and exit */
BB_EXECVP_or_die(argv);
}
}
int taskset_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int taskset_main(int argc UNUSED_PARAM, char **argv)
{
const char *pid_str;
char *aff;
unsigned opts;
/* 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:..." */
opts = getopt32(argv, "^+" "pa"IF_FEATURE_TASKSET_CPULIST("c")
"\0" "-1" /* at least 1 arg */);
argv += optind;
aff = *argv++;
if (!(opts & OPT_p)) {
/* <aff> <cmd...> */
if (!*argv)
bb_show_usage();
process_pid_str("0", opts, aff);
BB_EXECVP_or_die(argv);
}
pid_str = aff;
if (*argv) /* "-p <aff> <pid> ...rest.is.ignored..." */
pid_str = *argv; /* NB: *argv != NULL in this case */
else
aff = NULL;
if (opts & OPT_a) {
char dn[sizeof("/proc/%s/task") + 3 * sizeof(int)];
DIR *dir;
struct dirent *ent;
sprintf(dn, "/proc/%s/task", pid_str);
dir = opendir(dn);
if (!dir) {
goto no_threads;
}
while ((ent = readdir(dir)) != NULL) {
if (isdigit(ent->d_name[0]))
process_pid_str(ent->d_name, opts, aff);
}
IF_FEATURE_CLEAN_UP(closedir(dir);)
} else {
no_threads:
process_pid_str(pid_str, opts, aff);
}
return EXIT_SUCCESS;
}