Mercurial > hg > toybox
view toys/other/taskset.c @ 818:264b9da809df
Simplify license text, as mentioned on the mailing list.
Reasoning: it was never my intent to require anybody to copy license
text into another project if they cut and pasted something out of
toybox. The "permission for any purpose" is as close to public domain
as you can get in our current screwed up legal system without making
people uncomfortable the _other_ way. (Besides, my initial reading of
that was "all copies of the source code" but that's not what it says,
and somebody pointed out that Android has "show license text" options
because paranoid lawyers think that sort of thing applies to the BINARY
version, which is nuts.)
author | Rob Landley <rob@landley.net> |
---|---|
date | Thu, 14 Mar 2013 09:02:37 -0500 |
parents | 7e0cea8fbc3e |
children | 144d5ba7d410 |
line wrap: on
line source
/* taskset.c - Retrieve or set the CPU affinity of a process. * * Copyright 2012 Elie De Brauwer <eliedebrauwer@gmail.com> 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. */ #define FOR_taskset #include "toys.h" #include <sys/syscall.h> #define sched_setaffinity(pid, size, cpuset) \ syscall(__NR_sched_setaffinity, (pid_t)pid, (size_t)size, (void *)cpuset) #define sched_getaffinity(pid, size, cpuset) \ syscall(__NR_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 (-1 == 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<k; j++) { unsigned long digit = *(--s) - '0'; if (digit > 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 (-1 == 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); } }