- revert r15563 (pull current version of taskset off the busybox_scratch branch)

include/applets.h

@@ -284,6 +284,7 @@ USE_BB_SYSCTL(APPLET(sysctl, _BB_DIR_SBIN, _BB_SUID_NEVER))
 USE_SYSLOGD(APPLET(syslogd, _BB_DIR_SBIN, _BB_SUID_NEVER))
 USE_TAIL(APPLET(tail, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 USE_TAR(APPLET(tar, _BB_DIR_BIN, _BB_SUID_NEVER))
+USE_TASKSET(APPLET(taskset, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 USE_TEE(APPLET(tee, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 USE_TELNET(APPLET(telnet, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 USE_TELNETD(APPLET(telnetd, _BB_DIR_USR_SBIN, _BB_SUID_NEVER))

include/usage.h

@@ -3001,6 +3001,23 @@ USE_FEATURE_START_STOP_DAEMON_FANCY( \
 	"$ zcat /tmp/tarball.tar.gz | tar -xf -\n" \
 	"$ tar -cf /tmp/tarball.tar /usr/local\n"
 
+#define taskset_trivial_usage \
+	        "[OPTIONS] [mask] [pid | command [arg]...]"
+#define taskset_full_usage \
+	        "Set or get CPU affinity.\n\n" \
+        "Options:\n" \
+        "\t-p\toperate on an existing PID"
+#define taskset_example_usage \
+	        "$ taskset 0x7 ./dgemm_test&\n" \
+        "$ taskset -p 0x1 $!\n" \
+        "pid 4790's current affinity mask: 7\n" \
+        "pid 4790's new affinity mask: 1\n" \
+        "$ taskset 0x7 /bin/sh -c './taskset -p 0x1 $$'\n" \
+        "pid 6671's current affinity mask: 1\n" \
+        "pid 6671's new affinity mask: 1\n" \
+        "$ taskset -p 1\n"
+        "pid 1's current affinity mask: 3\n"
+
 #define tee_trivial_usage \
 	"[OPTION]... [FILE]..."
 #define tee_full_usage \

miscutils/Config.in

@@ -340,6 +340,16 @@ config TASKSET
 	default n
 	help
 	  Retrieve or set a processes's CPU affinity.
+	  This requires sched_{g,s}etaffinity support in your libc.
+
+config FEATURE_TASKSET_FANCY
+	bool "fancy output"
+	default y
+	depends on TASKSET
+	help
+	  Add code for fancy output. This merely silences a compiler-warning
+	  and adds about 135 Bytes. May be needed for machines with alot
+	  of CPUs.
 
 config TIME
 	bool "time"

miscutils/Kbuild

@@ -25,5 +25,6 @@ lib-$(CONFIG_RUNLEVEL)    += runlevel.o
 lib-$(CONFIG_RX)          += rx.o
 lib-$(CONFIG_SETSID)      += setsid.o
 lib-$(CONFIG_STRINGS)     += strings.o
+lib-$(CONFIG_TASKSET)     += taskset.o
 lib-$(CONFIG_TIME)        += time.o
 lib-$(CONFIG_WATCHDOG)    += watchdog.o

miscutils/taskset.c

@@ -0,0 +1,96 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * taskset - retrieve or set a processes' 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 */
+
+#if ENABLE_FEATURE_TASKSET_FANCY
+#define TASKSET_PRINTF_MASK "%s"
+#define from_cpuset(x) __from_cpuset(&x)
+/* craft a string from the mask */
+static char *__from_cpuset(cpu_set_t *mask) {
+	int i;
+	char *ret = 0, *str = xzalloc(9);
+
+	for (i = CPU_SETSIZE - 4; i >= 0; i -= 4) {
+		char val = 0;
+		int off;
+		for (off = 0; off <= 3; ++off)
+			if (CPU_ISSET(i+off, mask))
+				val |= 1<<off;
+
+		if (!ret && val)
+			ret = str;
+		*str++ = (val-'0'<=9) ? (val+48) : (val+87);
+	}
+	return ret;
+}
+#else
+#define TASKSET_PRINTF_MASK "%x"
+#define from_cpuset(mask) mask
+#endif
+
+#define TASKSET_OPT_p (1)
+
+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 = getopt32(argc, argv, "+p:", &p_opt);
+
+	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 = xatoul_range(p_opt, 1, ULONG_MAX); /* -p <pid> */
+	} else
+		aff = *++argv; /* <aff> <cmd...> */
+	if (aff) {
+		unsigned i = 0;
+		unsigned long l = xstrtol_range(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);
+		printf("pid %d's %s affinity mask: "TASKSET_PRINTF_MASK"\n",
+				pid, state, from_cpuset(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);
+}
+#undef TASKSET_OPT_p
+#undef TASKSET_PRINTF_MASK
+#undef from_cpuset