/* vi: set sw=4 ts=4: */ /* * taskset - retrieve or set a processes' CPU affinity * Copyright (c) 2006 Bernhard Fischer * * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */ #include "busybox.h" #include <sched.h> #include <getopt.h> /* optind */ #if ENABLE_FEATURE_TASKSET_FANCY #define TASKSET_PRINTF_MASK "%s" #define from_cpuset(x) __from_cpuset(&x) /* craft a string from the mask */ static char *__from_cpuset(cpu_set_t *mask) { int i; char *ret = 0, *str = xzalloc(9); for (i = CPU_SETSIZE - 4; i >= 0; i -= 4) { char 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++ = (val-'0'<=9) ? (val+48) : (val+87); } return ret; } #else #define TASKSET_PRINTF_MASK "%x" /* (void*) cast is for battling gcc: */ /* "dereferencing type-punned pointer will break strict-aliasing rules" */ #define from_cpuset(mask) (*(unsigned*)(void*)&(mask)) #endif #define OPT_p 1 int taskset_main(int argc, char** argv); int taskset_main(int argc, char** argv) { cpu_set_t mask, new_mask; pid_t pid = 0; unsigned opt; const char *state = "current\0new"; char *p_opt = NULL, *aff = NULL; opt = getopt32(argc, argv, "+p:", &p_opt); if (opt & OPT_p) { if (argc == optind+1) { /* -p <aff> <pid> */ aff = p_opt; p_opt = argv[optind]; } argv += optind; /* me -p <arg> */ pid = xatoul_range(p_opt, 1, ULONG_MAX); /* -p <pid> */ } else aff = *++argv; /* <aff> <cmd...> */ if (aff) { unsigned i = 0; unsigned long l = xstrtol_range(aff, 0, 1, LONG_MAX); CPU_ZERO(&new_mask); while (i < CPU_SETSIZE && l >= (1<<i)) { if ((1<<i) & l) CPU_SET(i, &new_mask); ++i; } } if (opt & OPT_p) { print_aff: if (sched_getaffinity(pid, sizeof(mask), &mask) < 0) bb_perror_msg_and_die("failed to %cet pid %d's affinity", 'g', pid); printf("pid %d's %s affinity mask: "TASKSET_PRINTF_MASK"\n", pid, state, from_cpuset(mask)); if (!*argv) /* no new affinity given or we did print already, done. */ return EXIT_SUCCESS; } if (sched_setaffinity(pid, sizeof(new_mask), &new_mask)) bb_perror_msg_and_die("failed to %cet pid %d's affinity", 's', pid); if (opt & OPT_p) { state += 8; ++argv; goto print_aff; } ++argv; BB_EXECVP(*argv, argv); bb_perror_msg_and_die("%s", *argv); } #undef OPT_p #undef TASKSET_PRINTF_MASK #undef from_cpuset