X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;ds=inline;f=miscutils%2Ftaskset.c;h=77fc8643d5eba73bca5a613de9bb09db1eae80ba;hb=c13ee8c0f32fa816e12f1ac0c55a800066dc1560;hp=cd8ffc8400d5a3739b6b2a7862576ed638afeecf;hpb=b6adbf1be29841501cc49917249e85f273e1df7c;p=oweals%2Fbusybox.git

diff --git a/miscutils/taskset.c b/miscutils/taskset.c
index cd8ffc840..77fc8643d 100644
--- a/miscutils/taskset.c
+++ b/miscutils/taskset.c
@@ -1,99 +1,154 @@
 /* vi: set sw=4 ts=4: */
 /*
  * taskset - retrieve or set a processes' CPU affinity
- * Copyright (c) 2006 Bernhard Fischer
+ * Copyright (c) 2006 Bernhard Reutner-Fischer
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
+//usage:#define taskset_trivial_usage
+//usage:       "[-p] [MASK] [PID | PROG ARGS]"
+//usage:#define taskset_full_usage "\n\n"
+//usage:       "Set or get CPU affinity\n"
+//usage:     "\nOptions:"
+//usage:     "\n	-p	Operate on an existing PID"
+//usage:
+//usage:#define taskset_example_usage
+//usage:       "$ taskset 0x7 ./dgemm_test&\n"
+//usage:       "$ taskset -p 0x1 $!\n"
+//usage:       "pid 4790's current affinity mask: 7\n"
+//usage:       "pid 4790's new affinity mask: 1\n"
+//usage:       "$ taskset 0x7 /bin/sh -c './taskset -p 0x1 $$'\n"
+//usage:       "pid 6671's current affinity mask: 1\n"
+//usage:       "pid 6671's new affinity mask: 1\n"
+//usage:       "$ taskset -p 1\n"
+//usage:       "pid 1's current affinity mask: 3\n"
+
 #include <sched.h>
-#include <getopt.h> /* optind */
 #include "libbb.h"
 
 #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)
+static char *from_cpuset(cpu_set_t *mask)
 {
 	int i;
-	char *ret = 0, *str = xzalloc(9);
+	char *ret = NULL;
+	char *str = xzalloc((CPU_SETSIZE / 4) + 1); /* we will leak it */
 
 	for (i = CPU_SETSIZE - 4; i >= 0; i -= 4) {
-		char val = 0;
+		int val = 0;
 		int off;
 		for (off = 0; off <= 3; ++off)
-			if (CPU_ISSET(i+off, mask))
-				val |= 1<<off;
-
+			if (CPU_ISSET(i + off, mask))
+				val |= 1 << off;
 		if (!ret && val)
 			ret = str;
-		*str++ = (val-'0'<=9) ? (val+48) : (val+87);
+		*str++ = bb_hexdigits_upcase[val] | 0x20;
 	}
 	return ret;
 }
 #else
-#define TASKSET_PRINTF_MASK "%x"
-/* (void*) cast is for battling gcc: */
-/* "dereferencing type-punned pointer will break strict-aliasing rules" */
-#define from_cpuset(mask) (*(unsigned*)(void*)&(mask))
+#define TASKSET_PRINTF_MASK "%llx"
+static unsigned long long from_cpuset(cpu_set_t *mask)
+{
+	struct BUG_CPU_SETSIZE_is_too_small {
+		char BUG_CPU_SETSIZE_is_too_small[
+			CPU_SETSIZE < sizeof(int) ? -1 : 1];
+	};
+	char *p = (void*)mask;
+
+	/* Take the least significant bits. Careful!
+	 * Consider both CPU_SETSIZE=4 and CPU_SETSIZE=1024 cases
+	 */
+#if BB_BIG_ENDIAN
+	/* For big endian, it means LAST bits */
+	if (CPU_SETSIZE < sizeof(long))
+		p += CPU_SETSIZE - sizeof(int);
+	else if (CPU_SETSIZE < sizeof(long long))
+		p += CPU_SETSIZE - sizeof(long);
+	else
+		p += CPU_SETSIZE - sizeof(long long);
+#endif
+	if (CPU_SETSIZE < sizeof(long))
+		return *(unsigned*)p;
+	if (CPU_SETSIZE < sizeof(long long))
+		return *(unsigned long*)p;
+	return *(unsigned long long*)p;
+}
 #endif
 
-#define OPT_p 1
 
-int taskset_main(int argc, char** argv);
-int taskset_main(int argc, char** argv)
+int taskset_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int taskset_main(int argc UNUSED_PARAM, char **argv)
 {
-	cpu_set_t mask, new_mask;
+	cpu_set_t mask;
 	pid_t pid = 0;
-	unsigned opt;
-	const char *state = "current\0new";
-	char *p_opt = NULL, *aff = NULL;
+	unsigned opt_p;
+	const char *current_new;
+	char *pid_str;
+	char *aff = aff; /* for compiler */
 
-	opt = getopt32(argc, argv, "+p:", &p_opt);
+	/* NB: we mimic util-linux's taskset: -p does not take
+	 * an argument, i.e., "-pN" is NOT valid, only "-p N"!
+	 * Indeed, util-linux-2.13-pre7 uses:
+	 * getopt_long(argc, argv, "+pchV", ...), not "...p:..." */
 
-	if (opt & 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, 0, 1, LONG_MAX);
-
-		CPU_ZERO(&new_mask);
-		while (i < CPU_SETSIZE && l >= (1<<i)) {
-			if ((1<<i) & l)
-				CPU_SET(i, &new_mask);
-			++i;
+	opt_complementary = "-1"; /* at least 1 arg */
+	opt_p = getopt32(argv, "+p");
+	argv += optind;
+
+	if (opt_p) {
+		pid_str = *argv++;
+		if (*argv) { /* "-p <aff> <pid> ...rest.is.ignored..." */
+			aff = pid_str;
+			pid_str = *argv; /* NB: *argv != NULL in this case */
 		}
+		/* else it was just "-p <pid>", and *argv == NULL */
+		pid = xatoul_range(pid_str, 1, ((unsigned)(pid_t)ULONG_MAX) >> 1);
+	} else {
+		aff = *argv++; /* <aff> <cmd...> */
+		if (!*argv)
+			bb_show_usage();
 	}
 
-	if (opt & OPT_p) {
+	current_new = "current\0new";
+	if (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_perror_msg_and_die("can't %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. */
+				pid, current_new, from_cpuset(&mask));
+		if (!*argv) {
+			/* Either it was just "-p <pid>",
+			 * or it was "-p <aff> <pid>" and we came here
+			 * for the second time (see goto below) */
 			return EXIT_SUCCESS;
+		}
+		*argv = NULL;
+		current_new += 8; /* "new" */
 	}
 
-	if (sched_setaffinity(pid, sizeof(new_mask), &new_mask))
-		bb_perror_msg_and_die("failed to %cet pid %d's affinity", 's', pid);
-	if (opt & OPT_p) {
-		state += 8;
-		++argv;
-		goto print_aff;
+	{ /* Affinity was specified, translate it into cpu_set_t */
+		unsigned i;
+		/* Do not allow zero mask: */
+		unsigned long long m = xstrtoull_range(aff, 0, 1, ULLONG_MAX);
+		enum { CNT_BIT = CPU_SETSIZE < sizeof(m)*8 ? CPU_SETSIZE : sizeof(m)*8 };
+
+		CPU_ZERO(&mask);
+		for (i = 0; i < CNT_BIT; i++) {
+			unsigned long long bit = (1ULL << i);
+			if (bit & m)
+				CPU_SET(i, &mask);
+		}
 	}
-	++argv;
-	BB_EXECVP(*argv, argv);
-	bb_perror_msg_and_die("%s", *argv);
+
+	/* Set pid's or our own (pid==0) affinity */
+	if (sched_setaffinity(pid, sizeof(mask), &mask))
+		bb_perror_msg_and_die("can't %cet pid %d's affinity", 's', pid);
+
+	if (!argv[0]) /* "-p <aff> <pid> [...ignored...]" */
+		goto print_aff; /* print new affinity and exit */
+
+	BB_EXECVP_or_die(argv);
 }
-#undef OPT_p
-#undef TASKSET_PRINTF_MASK
-#undef from_cpuset