diff options
author | Denys Vlasenko <vda.linux@googlemail.com> | 2014-08-17 21:36:22 +0400 |
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committer | Denys Vlasenko <vda.linux@googlemail.com> | 2014-08-17 21:36:22 +0400 |
commit | 962c4e822012a6d4c83b869eb47506881b4abc57 (patch) | |
tree | 6f23eaa2b896bcb65d081014682b564ffc0dd6fe /miscutils/taskset.c | |
parent | fb8d1ef2d00db013eae3cc675fc8b34fd0a7a987 (diff) |
taskset: support CPU masks for more than 64 CPUs
function old new delta
taskset_main 522 631 +109
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'miscutils/taskset.c')
-rw-r--r-- | miscutils/taskset.c | 86 |
1 files changed, 79 insertions, 7 deletions
diff --git a/miscutils/taskset.c b/miscutils/taskset.c index 4a9e3230d..8bd32ed61 100644 --- a/miscutils/taskset.c +++ b/miscutils/taskset.c @@ -6,6 +6,25 @@ * Licensed under GPLv2 or later, see file LICENSE in this source tree. */ +//config:config TASKSET +//config: bool "taskset" +//config: default n # doesn't build on some non-x86 targets (m68k) +//config: help +//config: Retrieve or set a processes's CPU affinity. +//config: This requires sched_{g,s}etaffinity support in your libc. +//config: +//config:config FEATURE_TASKSET_FANCY +//config: bool "Fancy output" +//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. + +//applet:IF_TASKSET(APPLET(taskset, BB_DIR_USR_BIN, BB_SUID_DROP)) +//kbuild:lib-$(CONFIG_TASKSET) += taskset.o + //usage:#define taskset_trivial_usage //usage: "[-p] [MASK] [PID | PROG ARGS]" //usage:#define taskset_full_usage "\n\n" @@ -22,6 +41,11 @@ //usage: "pid 6671's new affinity mask: 1\n" //usage: "$ taskset -p 1\n" //usage: "pid 1's current affinity mask: 3\n" +/* + Not yet implemented: + * -a/--all-tasks (affect all threads) + * -c/--cpu-list (specify CPUs via "1,3,5-7") + */ #include <sched.h> #include "libbb.h" @@ -128,17 +152,65 @@ int taskset_main(int argc UNUSED_PARAM, char **argv) current_new += 8; /* "new" */ } - { /* Affinity was specified, translate it into cpu_set_t */ + /* Affinity was specified, translate it into cpu_set_t */ + CPU_ZERO(&mask); + if (!ENABLE_FEATURE_TASKSET_FANCY) { unsigned i; + unsigned long long m; + /* Do not allow zero mask: */ - unsigned long long m = xstrtoull_range(aff, 0, 1, ULLONG_MAX); - enum { CNT_BIT = CPU_SETSIZE < sizeof(m)*8 ? CPU_SETSIZE : sizeof(m)*8 }; + m = xstrtoull_range(aff, 0, 1, ULLONG_MAX); + i = 0; + do { + if (m & 1) + CPU_SET(i, &mask); + i++; + m >>= 1; + } while (m != 0); + } 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: + bb_error_msg_and_die("bad affinity '%s'", aff); + } + last_byte--; /* now points to the last byte */ + } - CPU_ZERO(&mask); - for (i = 0; i < CNT_BIT; i++) { - unsigned long long bit = (1ULL << i); - if (bit & m) + 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); + //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--; + } } } |