c7b858ff8

Denys Vlasenko

2020-12-14

SUCCESS Duration: 150s

Subject

libbb: add and use infrastructure for fixed page size optimization

No binary (build failed)

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

—

(log yok)

archival/rpm.c+6 -4

@@ -83,7 +83,9 @@ struct globals {
	void *map;
	rpm_index *mytags;
	int tagcount;
-	unsigned mapsize, pagesize;
+	unsigned mapsize;
+	IF_VARIABLE_ARCH_PAGESIZE(unsigned pagesize;)
+	#define G_pagesize cached_pagesize(G.pagesize)
	} FIX_ALIASING;
	#define G ((struct globals)bb_common_bufsiz1)
	#define INIT_G() do { setup_common_bufsiz(); } while (0)
@@ -141,7 +143,7 @@ static int rpm_gettags(const char *filename)
	G.mytags = tags;

	/* Map the store */
-	storepos = (storepos + G.pagesize) & -(int)G.pagesize;
+	storepos = (storepos + G_pagesize) & -(int)G_pagesize;
	/* remember size for munmap */
	G.mapsize = storepos;
	/* some NOMMU systems prefer MAP_PRIVATE over MAP_SHARED */
@@ -356,7 +358,7 @@ int rpm_main(int argc, char **argv)
	int opt, func = 0;

	INIT_G();
-	G.pagesize = getpagesize();
+	INIT_PAGESIZE(G.pagesize);

	while ((opt = getopt(argc, argv, "iqpldc")) != -1) {
	switch (opt) {
@@ -523,7 +525,7 @@ int rpm2cpio_main(int argc UNUSED_PARAM, char **argv)
	int rpm_fd;

	INIT_G();
-	G.pagesize = getpagesize();
+	INIT_PAGESIZE(G.pagesize);

	rpm_fd = rpm_gettags(argv[1]);

include/libbb.h+18 -0

@@ -391,6 +391,24 @@ void *mmap_read(int fd, size_t size) FAST_FUNC;
	void *mmap_anon(size_t size) FAST_FUNC;
	void *xmmap_anon(size_t size) FAST_FUNC;

+	#if defined(__x86_64__) \|\| defined(i386)
+	# define BB_ARCH_FIXED_PAGESIZE 4096
+	#else /* if defined(ARCH) */
+	/* add you favorite arch today! */
+	#endif
+
+	#if defined BB_ARCH_FIXED_PAGESIZE
+	# define IF_VARIABLE_ARCH_PAGESIZE(...) /nothing/
+	# define bb_getpagesize() BB_ARCH_FIXED_PAGESIZE
+	# define INIT_PAGESIZE(var) ((void)0)
+	# define cached_pagesize(var) BB_ARCH_FIXED_PAGESIZE
+	#else
+	# define IF_VARIABLE_ARCH_PAGESIZE(...) __VA_ARGS__
+	# define bb_getpagesize() getpagesize()
+	# define INIT_PAGESIZE(var) ((var) = getpagesize())
+	# define cached_pagesize(var) (var)
+	#endif
+

	//TODO: supply a pointer to char[11] buffer (avoid statics)?
	extern const char *bb_mode_string(mode_t mode) FAST_FUNC;

libbb/procps.c+2 -2

@@ -94,15 +94,15 @@ static int read_to_buf(const char filename, void buf)

	static procps_status_t* FAST_FUNC alloc_procps_scan(void)
	{
-	unsigned n = getpagesize();
	procps_status_t* sp = xzalloc(sizeof(procps_status_t));
-	sp->dir = xopendir("/proc");
+	unsigned n = bb_getpagesize();
	while (1) {
	n >>= 1;
	if (!n) break;
	sp->shift_pages_to_bytes++;
	}
	sp->shift_pages_to_kb = sp->shift_pages_to_bytes - 10;
+	sp->dir = xopendir("/proc");
	return sp;
	}

miscutils/devmem.c+1 -1

@@ -75,7 +75,7 @@ int devmem_main(int argc UNUSED_PARAM, char **argv)
	bb_show_usage(); /* one of bb_strtouXX failed */

	fd = xopen("/dev/mem", argv[3] ? (O_RDWR \| O_SYNC) : (O_RDONLY \| O_SYNC));
-	mapped_size = page_size = getpagesize();
+	mapped_size = page_size = bb_getpagesize();
	offset_in_page = (unsigned)target & (page_size - 1);
	if (offset_in_page + width > page_size) {
	/* This access spans pages.

miscutils/hexedit.c+3 -11

@@ -31,7 +31,8 @@ struct globals {
	int fd;
	unsigned height;
	unsigned row;
-	unsigned pagesize;
+	IF_VARIABLE_ARCH_PAGESIZE(unsigned pagesize;)
+	#define G_pagesize cached_pagesize(G.pagesize)
	uint8_t *baseaddr;
	uint8_t *current_byte;
	uint8_t *eof_byte;
@@ -46,15 +47,6 @@ struct globals {
	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
	} while (0)

-	//TODO: move to libbb
-	#if defined(__x86_64__) \|\| defined(i386)
-	# define G_pagesize 4096
-	# define INIT_PAGESIZE() ((void)0)
-	#else
-	# define G_pagesize (G.pagesize)
-	# define INIT_PAGESIZE() ((void)(G.pagesize = getpagesize()))
-	#endif
-
	/* hopefully there aren't arches with PAGE_SIZE > 64k */
	#define G_mapsize (64*1024)

@@ -262,7 +254,7 @@ int hexedit_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
	int hexedit_main(int argc UNUSED_PARAM, char **argv)
	{
	INIT_G();
-	INIT_PAGESIZE();
+	INIT_PAGESIZE(G.pagesize);

	get_terminal_width_height(-1, NULL, &G.height);
	if (1) {

miscutils/time.c+6 -1

@@ -111,6 +111,10 @@ static void printargv(char const argv)
	This is funky since the pagesize could be less than 1K.
	Note: Some machines express getrusage statistics in terms of K,
	others in terms of pages. */
+	#ifdef BB_ARCH_FIXED_PAGESIZE
+	# define pagesize BB_ARCH_FIXED_PAGESIZE
+	# define ptok(pagesize, pages) ptok(pages)
+	#endif
	static unsigned long ptok(const unsigned pagesize, const unsigned long pages)
	{
	unsigned long tmp;
@@ -124,6 +128,7 @@ static unsigned long ptok(const unsigned pagesize, const unsigned long pages)
	tmp = pages * pagesize; /* Larger first, */
	return tmp / 1024; /* then smaller. */
	}
+	#undef pagesize

	/* summarize: Report on the system use of a command.

@@ -177,7 +182,7 @@ static void summarize(const char fmt, char command, resource_t resp)
	{
	unsigned vv_ms; /* Elapsed virtual (CPU) milliseconds */
	unsigned cpu_ticks; /* Same, in "CPU ticks" */
-	unsigned pagesize = getpagesize();
+	unsigned pagesize = bb_getpagesize();

	/* Impossible: we do not use WUNTRACED flag in wait()...
	if (WIFSTOPPED(resp->waitstatus))

util-linux/mkswap.c+1 -1

@@ -128,7 +128,7 @@ int mkswap_main(int argc UNUSED_PARAM, char **argv)

	/* Figure out how big the device is */
	len = get_volume_size_in_bytes(fd, argv[1], 1024, /extend:/ 1);
-	pagesize = getpagesize();
+	pagesize = bb_getpagesize();
	len -= pagesize;

	/* Announce our intentions */