199c0d542

Denis Vlasenko

2007-05-30

FAILED Duration: 10s

Subject

nmeter: stop using data/bss; reduce amount of reads from /proc # size */*/nmeter.o text data bss dec hex filename 4366 80 16 4462 116e busybox.t0/miscutils/nmeter.o 4386 0 0 4386 1122 busybox.t2/miscutils/nmeter.o

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

miscutils/nmeter.c +89 -48

miscutils/nmeter.c+89 -48

@@ -17,33 +17,67 @@

	typedef unsigned long long ullong;

-	enum { proc_file_size = 4096 };
+	enum { PROC_FILE_SIZE = 4096 };

	typedef struct proc_file {
-	const char *name;
-	int gen;
	char *file;
+	//const char *name;
+	smallint last_gen;
	} proc_file;

-	static proc_file proc_stat = { "/proc/stat", -1 };
-	static proc_file proc_loadavg = { "/proc/loadavg", -1 };
-	static proc_file proc_net_dev = { "/proc/net/dev", -1 };
-	static proc_file proc_meminfo = { "/proc/meminfo", -1 };
-	static proc_file proc_diskstats = { "/proc/diskstats", -1 };
-	// Sample #
-	static int gen = -1;
-	// Linux 2.6? (otherwise assumes 2.4)
-	static int is26 = 0;
-	static struct timeval tv;
-	static int delta = 1000000;
-	static int deltanz = 1000000;
-	static int need_seconds = 0;
-	static const char *final_str = "\n";
+	static const char *const proc_name[] = {
+	"stat", // Must match the order of proc_file's!
+	"loadavg",
+	"net/dev",
+	"meminfo",
+	"diskstats",
+	"sys/fs/file-nr",
+	};
+
+	struct globals {
+	// Sample generation flip-flop
+	smallint gen;
+	// Linux 2.6? (otherwise assumes 2.4)
+	smallint is26;
+	// 1 if sample delay is not an integer fraction of a second
+	smallint need_seconds;
+	char *cur_outbuf;
+	const char *final_str;
+	int delta;
+	int deltanz;
+	struct timeval tv;
+	#define first_proc_file proc_stat
+	proc_file proc_stat; // Must match the order of proc_name's!
+	proc_file proc_loadavg;
+	proc_file proc_net_dev;
+	proc_file proc_meminfo;
+	proc_file proc_diskstats;
+	proc_file proc_sys_fs_filenr;
+	};
+	#define G (*ptr_to_globals)
+	#define gen (G.gen )
+	#define is26 (G.is26 )
+	#define need_seconds (G.need_seconds )
+	#define cur_outbuf (G.cur_outbuf )
+	#define final_str (G.final_str )
+	#define delta (G.delta )
+	#define deltanz (G.deltanz )
+	#define tv (G.tv )
+	#define proc_stat (G.proc_stat )
+	#define proc_loadavg (G.proc_loadavg )
+	#define proc_net_dev (G.proc_net_dev )
+	#define proc_meminfo (G.proc_meminfo )
+	#define proc_diskstats (G.proc_diskstats )
+	#define proc_sys_fs_filenr (G.proc_sys_fs_filenr)

	// We depend on this being a char[], not char* - we take sizeof() of it
	#define outbuf bb_common_bufsiz1
-	static char *cur_outbuf = outbuf;

+	#define INIT_G() do { \
+	cur_outbuf = outbuf; \
+	final_str = "\n"; \
+	deltanz = delta = 1000000; \
+	} while (0)

	static inline void reset_outbuf(void)
	{
@@ -85,27 +119,31 @@ static void put_question_marks(int count)
	put_c('?');
	}

-	static int readfile_z(char buf, int sz, const char fname)
+	static void readfile_z(char buf, int sz, const char fname)
	{
-	sz = open_read_close(fname, buf, sz-1);
-	if (sz < 0) {
-	buf[0] = '\0';
-	return 1;
+	// open_read_close() will do two reads in order to be sure we are at EOF,
+	// and we don't need/want that.
+	// sz = open_read_close(fname, buf, sz-1);
+
+	int fd = xopen(fname, O_RDONLY);
+	buf[0] = '\0';
+	if (fd >= 0) {
+	sz = read(fd, buf, sz-1);
+	if (sz > 0) buf[sz] = '\0';
+	close(fd);
	}
-	buf[sz] = '\0';
-	return 0;
	}

	static const char* get_file(proc_file *pf)
	{
-	if (pf->gen != gen) {
-	pf->gen = gen;
-	// We allocate proc_file_size bytes. This wastes memory,
+	if (pf->last_gen != gen) {
+	pf->last_gen = gen;
+	// We allocate PROC_FILE_SIZE bytes. This wastes memory,
	// but allows us to allocate only once (at first sample)
	// per proc file, and reuse buffer for each sample
	if (!pf->file)
-	pf->file = xmalloc(proc_file_size);
-	readfile_z(pf->file, proc_file_size, pf->name);
+	pf->file = xmalloc(PROC_FILE_SIZE);
+	readfile_z(pf->file, PROC_FILE_SIZE, proc_name[pf - &first_proc_file]);
	}
	return pf->file;
	}
@@ -242,10 +280,10 @@ static s_stat* init_literal(void)

	static s_stat* init_delay(const char *param)
	{
-	delta = strtol(param, NULL, 0)*1000;
+	delta = bb_strtoi(param, NULL, 0) * 1000;
	deltanz = delta > 0 ? delta : 1;
	need_seconds = (1000000%deltanz) != 0;
-	return (s_stat*)0;
+	return NULL;
	}

	static s_stat* init_cr(const char *param)
@@ -281,7 +319,7 @@ static void collect_cpu(cpu_stat *s)
	return;
	}

-	for (i=0; i<CPU_FIELDCNT; i++) {
+	for (i = 0; i < CPU_FIELDCNT; i++) {
	ullong old = s->old[i];
	if (data[i] < old) old = data[i]; //sanitize
	s->old[i] = data[i];
@@ -289,7 +327,7 @@ static void collect_cpu(cpu_stat *s)
	}

	if (all) {
-	for (i=0; i<CPU_FIELDCNT; i++) {
+	for (i = 0; i < CPU_FIELDCNT; i++) {
	ullong t = bar_sz * data[i];
	norm_all += data[i] = t / all;
	frac[i] = t % all;
@@ -298,7 +336,7 @@ static void collect_cpu(cpu_stat *s)
	while (norm_all < bar_sz) {
	unsigned max = frac[0];
	int pos = 0;
-	for (i=1; i<CPU_FIELDCNT; i++) {
+	for (i = 1; i < CPU_FIELDCNT; i++) {
	if (frac[i] > max) max = frac[i], pos = i;
	}
	frac[pos] = 0; //avoid bumping up same value twice
@@ -640,11 +678,9 @@ S_STAT_END(fd_stat)

	static void collect_fd(fd_stat *s)
	{
-	char file[4096];
	ullong data[2];

-	readfile_z(file, sizeof(file), "/proc/sys/fs/file-nr");
-	if (rdval(file, "", data, 1, 2)) {
+	if (rdval(get_file(&proc_sys_fs_filenr), "", data, 1, 2)) {
	put_question_marks(4);
	return;
	}
@@ -702,7 +738,7 @@ static s_stat* init_time(const char *param)

	static void collect_info(s_stat *s)
	{
-	gen++;
+	gen ^= 1;
	while (s) {
	put(s->label);
	s->collect(s);
@@ -714,7 +750,7 @@ static void collect_info(s_stat *s)
	typedef s_stat* init_func(const char *param);

	static const char options[] = "ncmsfixptbdr";
-	static init_func* init_functions[] = {
+	static init_func *const init_functions[] = {
	init_if,
	init_cpu,
	init_mem,
@@ -738,10 +774,15 @@ int nmeter_main(int argc, char **argv)
	s_stat *s;
	char cur, prev;

+	PTR_TO_GLOBALS = xzalloc(sizeof(G));
+	INIT_G();
+
+	xchdir("/proc");
+
	if (argc != 2)
	bb_show_usage();

-	if (open_read_close("/proc/version", buf, sizeof(buf)) > 0)
+	if (open_read_close("version", buf, sizeof(buf)) > 0)
	is26 = (strstr(buf, " 2.4.")==NULL);

	// Can use argv[1] directly, but this will mess up
@@ -750,11 +791,11 @@ int nmeter_main(int argc, char **argv)
	while (1) {
	char param, p;
	prev = cur;
-	again:
+	again:
	cur = strchr(cur, '%');
	if (!cur)
	break;
-	if (cur[1]=='%') { // %%
+	if (cur[1] == '%') { // %%
	strcpy(cur, cur+1);
	cur++;
	goto again;
@@ -813,12 +854,12 @@ again:
	collect_info(first);
	reset_outbuf();
	if (delta >= 0) {
-	gettimeofday(&tv, 0);
+	gettimeofday(&tv, NULL);
	usleep(delta > 1000000 ? 1000000 : delta - tv.tv_usec%deltanz);
	}

	while (1) {
-	gettimeofday(&tv, 0);
+	gettimeofday(&tv, NULL);
	collect_info(first);
	put(final_str);
	print_outbuf();
@@ -831,9 +872,9 @@ again:
	if (delta >= 0) {
	int rem;
	// can be commented out, will sacrifice sleep time precision a bit
-	gettimeofday(&tv, 0);
+	gettimeofday(&tv, NULL);
	if (need_seconds)
-	rem = delta - ((ullong)tv.tv_sec*1000000+tv.tv_usec)%deltanz;
+	rem = delta - ((ullong)tv.tv_sec*1000000 + tv.tv_usec) % deltanz;
	else
	rem = delta - tv.tv_usec%deltanz;
	// Sometimes kernel wakes us up just a tiny bit earlier than asked
@@ -845,5 +886,5 @@ again:
	}
	}

-	return 0;
+	/return 0;/
	}