taskset: simplify code a bit; tweak --help

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2017-01-30 22:20:06 +01:00
parent ca659f84b2
commit d6ace66973

View File

@ -26,7 +26,7 @@
//kbuild:lib-$(CONFIG_TASKSET) += taskset.o
//usage:#define taskset_trivial_usage
//usage: "[-p] [HEXMASK] [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"
@ -116,7 +116,7 @@ int taskset_main(int argc UNUSED_PARAM, char **argv)
pid_t pid = 0;
unsigned opt_p;
const char *current_new;
char *aff = aff; /* for compiler */
char *aff;
/* NB: we mimic util-linux's taskset: -p does not take
* an argument, i.e., "-pN" is NOT valid, only "-p N"!
@ -127,29 +127,28 @@ int taskset_main(int argc UNUSED_PARAM, char **argv)
opt_p = getopt32(argv, "+p");
argv += optind;
aff = *argv++;
if (opt_p) {
char *pid_str = *argv++;
char *pid_str = aff;
if (*argv) { /* "-p <aff> <pid> ...rest.is.ignored..." */
aff = pid_str;
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 = *argv++; /* <aff> <cmd...> */
/* <aff> <cmd...> */
if (!*argv)
bb_show_usage();
}
mask_size_in_bytes = SZOF_UL;
mask = NULL;
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) {
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) */
@ -166,8 +165,7 @@ int taskset_main(int argc UNUSED_PARAM, char **argv)
aff += 2;
if (!ENABLE_FEATURE_TASKSET_FANCY) {
/* Do not allow zero mask: */
mask[0] = xstrtoul_range(aff, 16, 1, ULONG_MAX);
mask[0] = xstrtoul(aff, 16);
} else {
unsigned i;
char *last_char;
@ -201,8 +199,8 @@ int taskset_main(int argc UNUSED_PARAM, char **argv)
/* 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,
* 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.