From 3a9241add947cb6d24b5de7a8927517426a78795 Mon Sep 17 00:00:00 2001 From: Rob Landley Date: Sat, 25 Aug 2012 14:25:22 -0500 Subject: Move commands into "posix", "lsb", and "other" menus/directories. --- toys/other/taskset.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 toys/other/taskset.c (limited to 'toys/other/taskset.c') diff --git a/toys/other/taskset.c b/toys/other/taskset.c new file mode 100644 index 00000000..7ac3b572 --- /dev/null +++ b/toys/other/taskset.c @@ -0,0 +1,110 @@ +/* vi: set sw=4 ts=4: + * + * taskset.c - Retrieve or set the CPU affinity of a process. + * + * Copyright 2012 Elie De Brauwer + * + * No standard. + +USE_TASKSET(NEWTOY(taskset, "<1^pa", TOYFLAG_BIN|TOYFLAG_STAYROOT)) + +config TASKSET + bool "taskset" + default y + help + usage: taskset [-ap] [mask] [PID | cmd [args...]] + + Launch a new task which may only run on certain processors, or change + the processor affinity of an exisitng PID. + + Mask is a hex string where each bit represents a processor the process + is allowed to run on. PID without a mask displays existing affinity. + + -p Set/get the affinity of given PID instead of a new command. + -a Set/get the affinity of all threads of the PID. +*/ + +#include "toys.h" + +#define FLAG_a 0x1 +#define FLAG_p 0x2 + +// Prototype for syscall wrappers sched.h refuses to give us +int sched_setaffinity(pid_t pid, size_t size, void *cpuset); +int sched_getaffinity(pid_t pid, size_t size, void *cpuset); + +// mask is an array of long, which makes the layout a bit weird on big +// endian systems but as long as it's consistent... + +static void do_taskset(pid_t pid, int quiet) +{ + unsigned long *mask = (unsigned long *)toybuf; + char *s = *toys.optargs, *failed = "failed to %s %d's affinity"; + int i, j, k; + + for (i=0; ; i++) { + if (!quiet) { + int j = sizeof(toybuf), flag = 0; + + if (sched_getaffinity(pid, sizeof(toybuf), (void *)mask)) + perror_exit(failed, "get", pid); + + printf("pid %d's %s affinity mask: ", pid, i ? "new" : "current"); + + while (j--) { + int x = 255 & (mask[j/sizeof(long)] >> (8*(j&(sizeof(long)-1)))); + + if (flag) printf("%02x", x); + else if (x) { + flag++; + printf("%x", x); + } + } + putchar('\n'); + } + + if (i || toys.optc < 2) return; + + memset(toybuf, 0, sizeof(toybuf)); + k = strlen(s = *toys.optargs); + s += k; + for (j = 0; j 9) digit = 10 + tolower(*s)-'a'; + if (digit > 15) error_exit("bad mask '%s'", *toys.optargs); + mask[j/(2*sizeof(long))] |= digit << 4*(j&((2*sizeof(long))-1)); + } + + if (sched_setaffinity(pid, sizeof(toybuf), (void *)mask)) + perror_exit(failed, "set", pid); + } +} + +static int task_callback(struct dirtree *new) +{ + if (!new->parent) return DIRTREE_RECURSE; + if (isdigit(*new->name)) do_taskset(atoi(new->name), 0); + + return 0; +} + +void taskset_main(void) +{ + if (!(toys.optflags & FLAG_p)) { + if (toys.optc < 2) error_exit("Needs 2 args"); + do_taskset(getpid(), 1); + xexec(toys.optargs+1); + } else { + char *c; + pid_t pid = strtol(toys.optargs[toys.optc-1], &c, 10); + + if (*c) error_exit("Not int %s", toys.optargs[1]); + + if (toys.optflags & FLAG_a) { + char buf[33]; + sprintf(buf, "/proc/%ld/task/", (long)pid); + dirtree_read(buf, task_callback); + } else do_taskset(pid, 0); + } +} -- cgit v1.2.3