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    Contents of /trunk/mkinitrd-magellan/busybox/miscutils/taskset.c

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    Revision 532 - (show annotations) (download)
    Sat Sep 1 22:45:15 2007 UTC (16 years, 8 months ago) by niro
    File MIME type: text/plain
    File size: 2372 byte(s) 
    -import if magellan mkinitrd; it is a fork of redhats mkinitrd-5.0.8 with all magellan patches and features; deprecates magellan-src/mkinitrd
    1 /* vi: set sw=4 ts=4: */
    2 /*
    3 * taskset - retrieve or set a processes' CPU affinity
    4 * Copyright (c) 2006 Bernhard Fischer
    5 *
    6 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
    7 */
    8
    9 #include "busybox.h"
    10 #include <sched.h>
    11 #include <getopt.h> /* optind */
    12
    13 #if ENABLE_FEATURE_TASKSET_FANCY
    14 #define TASKSET_PRINTF_MASK "%s"
    15 #define from_cpuset(x) __from_cpuset(&x)
    16 /* craft a string from the mask */
    17 static char *__from_cpuset(cpu_set_t *mask)
    18 {
    19 int i;
    20 char *ret = 0, *str = xzalloc(9);
    21
    22 for (i = CPU_SETSIZE - 4; i >= 0; i -= 4) {
    23 char val = 0;
    24 int off;
    25 for (off = 0; off <= 3; ++off)
    26 if (CPU_ISSET(i+off, mask))
    27 val |= 1<<off;
    28
    29 if (!ret && val)
    30 ret = str;
    31 *str++ = (val-'0'<=9) ? (val+48) : (val+87);
    32 }
    33 return ret;
    34 }
    35 #else
    36 #define TASKSET_PRINTF_MASK "%x"
    37 /* (void*) cast is for battling gcc: */
    38 /* "dereferencing type-punned pointer will break strict-aliasing rules" */
    39 #define from_cpuset(mask) (*(unsigned*)(void*)&(mask))
    40 #endif
    41
    42 #define OPT_p 1
    43
    44 int taskset_main(int argc, char** argv)
    45 {
    46 cpu_set_t mask, new_mask;
    47 pid_t pid = 0;
    48 unsigned opt;
    49 const char *state = "current\0new";
    50 char *p_opt = NULL, *aff = NULL;
    51
    52 opt = getopt32(argc, argv, "+p:", &p_opt);
    53
    54 if (opt & OPT_p) {
    55 if (argc == optind+1) { /* -p <aff> <pid> */
    56 aff = p_opt;
    57 p_opt = argv[optind];
    58 }
    59 argv += optind; /* me -p <arg> */
    60 pid = xatoul_range(p_opt, 1, ULONG_MAX); /* -p <pid> */
    61 } else
    62 aff = *++argv; /* <aff> <cmd...> */
    63 if (aff) {
    64 unsigned i = 0;
    65 unsigned long l = xstrtol_range(aff, 16, 1, ULONG_MAX);
    66
    67 CPU_ZERO(&new_mask);
    68 while (i < CPU_SETSIZE && l >= (1<<i)) {
    69 if ((1<<i) & l)
    70 CPU_SET(i, &new_mask);
    71 ++i;
    72 }
    73 }
    74
    75 if (opt & OPT_p) {
    76 print_aff:
    77 if (sched_getaffinity(pid, sizeof(mask), &mask) < 0)
    78 bb_perror_msg_and_die("failed to %cet pid %d's affinity", 'g', pid);
    79 printf("pid %d's %s affinity mask: "TASKSET_PRINTF_MASK"\n",
    80 pid, state, from_cpuset(mask));
    81 if (!*argv) /* no new affinity given or we did print already, done. */
    82 return EXIT_SUCCESS;
    83 }
    84
    85 if (sched_setaffinity(pid, sizeof(new_mask), &new_mask))
    86 bb_perror_msg_and_die("failed to %cet pid %d's affinity", 's', pid);
    87 if (opt & OPT_p) {
    88 state += 8;
    89 ++argv;
    90 goto print_aff;
    91 }
    92 ++argv;
    93 execvp(*argv, argv);
    94 bb_perror_msg_and_die("%s", *argv);
    95 }
    96 #undef OPT_p
    97 #undef TASKSET_PRINTF_MASK
    98 #undef from_cpuset