diff options
| -rw-r--r-- | miscutils/taskset.c | 205 |
1 files changed, 103 insertions, 102 deletions
diff --git a/miscutils/taskset.c b/miscutils/taskset.c index fb352ab..a87b9bd 100644 --- a/miscutils/taskset.c +++ b/miscutils/taskset.c @@ -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 cpu_set_t */ - CPU_ZERO(&mask); - if (!ENABLE_FEATURE_TASKSET_FANCY) { - unsigned i; - unsigned long long m; + /* 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; + if (!ENABLE_FEATURE_TASKSET_FANCY) { /* 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; - - /* Cheap way to get "long enough" buffer */ - bin = xstrdup(aff); - - 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: + char *last_char; + + i = 0; /* bit pos in mask[] */ + + /* 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 */ |