123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132 |
- /* 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_USR|TOYFLAG_BIN|TOYFLAG_STAYROOT))
- USE_NPROC(NEWTOY(nproc, "(all)", TOYFLAG_USR|TOYFLAG_BIN))
- config NPROC
- bool "nproc"
- default y
- help
- usage: nproc [--all]
- Print number of processors.
- --all Show all processors, not just ones this task can run on
- 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 existing 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"
- #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);
- }
- }
- void nproc_main(void)
- {
- unsigned i, j, nproc = 0;
- // This can only detect 32768 processors. Call getaffinity and count bits.
- if (!toys.optflags && -1!=sched_getaffinity(getpid(), 4096, toybuf)) {
- for (i = 0; i<4096; i++)
- if (toybuf[i]) for (j=0; j<8; j++) if (toybuf[i]&(1<<j)) nproc++;
- }
- // If getaffinity failed or --all, count cpu entries in proc
- if (!nproc) nproc = sysconf(_SC_NPROCESSORS_CONF);
- xprintf("%u\n", nproc);
- }
|