libbb: factor out common code from mpstat/iostat

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

include/libbb.h

@@ -1479,6 +1479,8 @@ procps_status_t* procps_scan(procps_status_t* sp, int flags) FAST_FUNC;
 void read_cmdline(char *buf, int size, unsigned pid, const char *comm) FAST_FUNC;
 pid_t *find_pid_by_name(const char* procName) FAST_FUNC;
 pid_t *pidlist_reverse(pid_t *pidList) FAST_FUNC;
+int starts_with_cpu(const char *str) FAST_FUNC;
+unsigned get_cpu_count(void) FAST_FUNC;
 
 
 extern const char bb_uuenc_tbl_base64[];

libbb/Kbuild.src

@@ -157,6 +157,9 @@ lib-$(CONFIG_MOUNT) += find_mount_point.o
 lib-$(CONFIG_HWCLOCK) += rtc.o
 lib-$(CONFIG_RTCWAKE) += rtc.o
 
+lib-$(CONFIG_IOSTAT) += get_cpu_count.o
+lib-$(CONFIG_MPSTAT) += get_cpu_count.o
+
 # We shouldn't build xregcomp.c if we don't need it - this ensures we don't
 # require regex.h to be in the include dir even if we don't need it thereby
 # allowing us to build busybox even if uclibc regex support is disabled.

libbb/get_cpu_count.c

@@ -0,0 +1,47 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Factored out of mpstat/iostat.
+ *
+ * Copyright (C) 2010 Marek Polacek <mmpolacek@gmail.com>
+ *
+ * Licensed under GPLv2, see file License in this tarball for details.
+ */
+#include "libbb.h"
+
+/* Does str start with "cpu"? */
+int FAST_FUNC starts_with_cpu(const char *str)
+{
+	return ((str[0] - 'c') | (str[1] - 'p') | (str[2] - 'u')) == 0;
+}
+
+/*
+ * Get number of processors. Uses /proc/stat.
+ * Return value 0 means one CPU and non SMP kernel.
+ * Otherwise N means N processor(s) and SMP kernel.
+ */
+unsigned FAST_FUNC get_cpu_count(void)
+{
+	FILE *fp;
+	char line[256];
+	int proc_nr = -1;
+
+	fp = xfopen_for_read("/proc/stat");
+	while (fgets(line, sizeof(line), fp)) {
+		if (!starts_with_cpu(line)) {
+			if (proc_nr >= 0)
+				break; /* we are past "cpuN..." lines */
+			continue;
+		}
+		if (line[3] != ' ') { /* "cpuN" */
+			int num_proc;
+			if (sscanf(line + 3, "%u", &num_proc) == 1
+			 && num_proc > proc_nr
+			) {
+				proc_nr = num_proc;
+			}
+		}
+	}
+
+	fclose(fp);
+	return proc_nr + 1;
+}

procps/iostat.c

@@ -114,26 +114,6 @@ static void print_header(void)
 			buf, uts.machine, G.total_cpus);
 }
 
-static int get_number_of_cpus(void)
-{
-#ifdef _SC_NPROCESSORS_CONF
-	return sysconf(_SC_NPROCESSORS_CONF);
-#else
-	char buf[128];
-	int n = 0;
-	FILE *fp;
-
-	fp = xfopen_for_read("/proc/cpuinfo");
-
-	while (fgets(buf, sizeof(buf), fp))
-		if (strncmp(buf, "processor\t:", 11) == 0)
-			n++;
-
-	fclose(fp);
-	return n;
-#endif
-}
-
 static void get_localtime(struct tm *ptm)
 {
 	time_t timer;
@@ -148,12 +128,6 @@ static void print_timestamp(void)
 	printf("%s\n", buf);
 }
 
-/* Does str start with "cpu"? */
-static int starts_with_cpu(const char *str)
-{
-	return ((str[0] - 'c') | (str[1] - 'p') | (str[2] - 'u')) == 0;
-}
-
 /* Fetch CPU statistics from /proc/stat */
 static void get_cpu_statistics(struct stats_cpu *sc)
 {
@@ -509,7 +483,9 @@ int iostat_main(int argc, char **argv)
 	G.clk_tck = get_user_hz();
 
 	/* Determine number of CPUs */
-	G.total_cpus = get_number_of_cpus();
+	G.total_cpus = get_cpu_count();
+	if (G.total_cpus == 0)
+		G.total_cpus = 1;
 
 	/* Parse and process arguments */
 	/* -k and -m are mutually exclusive */

procps/mpstat.c

@@ -119,12 +119,6 @@ enum {
 };
 
 
-/* Does str start with "cpu"? */
-static int starts_with_cpu(const char *str)
-{
-	return !((str[0] - 'c') | (str[1] - 'p') | (str[2] - 'u'));
-}
-
 /* Is option on? */
 static ALWAYS_INLINE int display_opt(int opt)
 {
@@ -815,38 +809,6 @@ static void print_header(struct tm *t)
 		uts.sysname, uts.release, uts.nodename, cur_date, uts.machine, G.cpu_nr);
 }
 
-/*
- * Get number of processors in /proc/stat
- * Return value '0' means one CPU and non SMP kernel.
- * Otherwise N means N processor(s) and SMP kernel.
- */
-static int get_cpu_nr(void)
-{
-	FILE *fp;
-	char line[256];
-	int proc_nr = -1;
-
-	fp = xfopen_for_read(PROCFS_STAT);
-	while (fgets(line, sizeof(line), fp)) {
-		if (!starts_with_cpu(line)) {
-			if (proc_nr >= 0)
-				break; /* we are past "cpuN..." lines */
-			continue;
-		}
-		if (line[3] != ' ') { /* "cpuN" */
-			int num_proc;
-			if (sscanf(line + 3, "%u", &num_proc) == 1
-			 && num_proc > proc_nr
-			) {
-				proc_nr = num_proc;
-			}
-		}
-	}
-
-	fclose(fp);
-	return proc_nr + 1;
-}
-
 /*
  * Get number of interrupts available per processor
  */
@@ -910,7 +872,7 @@ int mpstat_main(int UNUSED_PARAM argc, char **argv)
 	G.interval = -1;
 
 	/* Get number of processors */
-	G.cpu_nr = get_cpu_nr();
+	G.cpu_nr = get_cpu_count();
 
 	/* Get number of clock ticks per sec */
 	G.hz = get_hz();