- add applet taskset to set/retrieve the CPU affinity of a process

   text    data     bss     dec     hex filename
    584       0       0     584     248 taskset.o.gcc-2.95
    509       0       0     509     1fd taskset.o.gcc-3.3
    505       0       0     505     1f9 taskset.o.gcc-3.4
    506       0       0     506     1fa taskset.o.gcc-4.0
    498       0       0     498     1f2 taskset.o.gcc-4.1
    495       0       0     495     1ef taskset.o.gcc-4.2-HEAD

1 files changed, 67 insertions, 0 deletions

diff --git a/miscutils/taskset.c b/miscutils/taskset.c
new file mode 100644
index 000000000..a72f3ff53
--- /dev/null
+++ b/miscutils/taskset.c
@@ -0,0 +1,67 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * taskset - retrieve or set a processes's CPU affinity
+ * Copyright (c) 2006 Bernhard Fischer
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+#include "busybox.h"
+#include <sched.h>
+#include <unistd.h>
+#include <getopt.h> /* optind */
+
+int taskset_main(int argc, char** argv)
+{
+        cpu_set_t mask, new_mask;
+        pid_t pid = 0;
+        unsigned long ul;
+        const char *state = "current\0new";
+        char *p_opt = NULL, *aff = NULL;
+
+        ul = bb_getopt_ulflags(argc, argv, "+p:", &p_opt);
+#define TASKSET_OPT_p (1)
+
+        if (ul & TASKSET_OPT_p) {
+                if (argc == optind+1) { /* -p <aff> <pid> */
+                        aff = p_opt;
+                        p_opt = argv[optind];
+                }
+                argv += optind; /* me -p <arg> */
+                pid = bb_xgetularg10_bnd(p_opt, 1, ULONG_MAX); /* -p <pid> */
+        } else
+                aff = *++argv; /* <aff> <cmd...> */
+        if (aff) {
+/*              to_cpuset(bb_xgetularg_bnd(aff, 16, 1, ULONG_MAX), &new_mask); */
+                unsigned i = 0;
+                unsigned long l = bb_xgetularg_bnd(aff, 16, 1, ULONG_MAX);
+
+                CPU_ZERO(&new_mask);
+                while (i < CPU_SETSIZE && l >= (1<<i)) {
+                        if ((1<<i) & l)
+                                CPU_SET(i, &new_mask);
+                        ++i;
+                }
+        }
+
+        if (ul & TASKSET_OPT_p) {
+print_aff:
+                if (sched_getaffinity(pid, sizeof (mask), &mask) < 0)
+                        bb_perror_msg_and_die("Failed to %cet pid %d's affinity", 'g', pid);
+                bb_printf("pid %d's %s affinity mask: %x\n", /* %x .. perhaps _FANCY */
+                                pid, state, mask);
+                if (!*argv) /* no new affinity given or we did print already, done. */
+                        return EXIT_SUCCESS;
+        }
+
+        if (sched_setaffinity(pid, sizeof (new_mask), &new_mask))
+                bb_perror_msg_and_die("Failed to %cet pid %d's affinity", 's', pid);
+        if (ul & TASKSET_OPT_p) {
+                state += 8;
+                ++argv;
+                goto print_aff;
+        }
+        ++argv;
+        execvp(*argv, argv);
+        bb_perror_msg_and_die("%s", *argv);
+}