From e6a2f4cc5a47d3022bdf5ca2cacbaa5a8c5baf7a Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Thu, 21 Apr 2016 16:26:30 +0200 Subject: libbb: make bb_common_bufsiz1 1 kbyte, add capability to use bss tail for it The config item is FEATURE_USE_BSS_TAIL. When it is off (default): function old new delta read_config 210 228 +18 doCommands 2279 2294 +15 ipneigh_list_or_flush 763 772 +9 ipaddr_list_or_flush 1256 1261 +5 display_process_list 1301 1306 +5 conspy_main 1378 1383 +5 do_lzo_compress 352 355 +3 do_lzo_decompress 565 567 +2 push 46 44 -2 inetd_main 2136 2134 -2 uevent_main 421 418 -3 addLines 97 92 -5 bb_common_bufsiz1 8193 1024 -7169 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 8/5 up/down: 62/-7181) Total: -7119 bytes text data bss dec hex filename 829850 4086 9080 843016 cdd08 busybox_old 829901 4086 1904 835891 cc133 busybox_unstripped FEATURE_USE_BSS_TAIL=y: read_config 210 228 +18 doCommands 2279 2294 +15 ipneigh_list_or_flush 763 772 +9 ipaddr_list_or_flush 1256 1261 +5 display_process_list 1301 1306 +5 conspy_main 1378 1383 +5 do_lzo_compress 352 355 +3 do_lzo_decompress 565 567 +2 inetd_main 2136 2134 -2 bb_common_bufsiz1 8193 - -8193 ------------------------------------------------------------------------------ (add/remove: 0/1 grow/shrink: 8/1 up/down: 62/-8195) Total: -8133 bytes text data bss dec hex filename 829850 4086 9080 843016 cdd08 busybox_old 829911 4086 880 834877 cbd3d busybox_unstripped FIXME: setup_common_bufsiz() calls are missing. Signed-off-by: Denys Vlasenko --- include/libbb.h | 4 ---- 1 file changed, 4 deletions(-) (limited to 'include') diff --git a/include/libbb.h b/include/libbb.h index 111dd66e0..fd40ef74c 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -1827,10 +1827,6 @@ extern const char bb_PATH_root_path[] ALIGN1; /* "PATH=/sbin:/usr/sbin:/bin:/usr extern const int const_int_0; //extern const int const_int_1; - -/* Providing hard guarantee on minimum size (think of BUFSIZ == 128) */ -enum { COMMON_BUFSIZE = (BUFSIZ >= 256*sizeof(void*) ? BUFSIZ+1 : 256*sizeof(void*)) }; -extern char bb_common_bufsiz1[COMMON_BUFSIZE]; /* This struct is deliberately not defined. */ /* See docs/keep_data_small.txt */ struct globals; -- cgit v1.2.3-55-g6feb From 4c8fa34417fd2ccdda6a8ea508a3f1e7fb1d4ceb Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sun, 24 Apr 2016 14:13:35 +0200 Subject: generate_BUFSIZ.sh: yet another tweak Signed-off-by: Denys Vlasenko --- include/.gitignore | 1 + scripts/generate_BUFSIZ.sh | 54 +++++++++++++++++++++++++++++++++++----------- 2 files changed, 42 insertions(+), 13 deletions(-) (limited to 'include') diff --git a/include/.gitignore b/include/.gitignore index 9d9b6c499..75afff9ca 100644 --- a/include/.gitignore +++ b/include/.gitignore @@ -8,3 +8,4 @@ /NUM_APPLETS.h /usage_compressed.h /usage.h +/common_bufsiz.h* diff --git a/scripts/generate_BUFSIZ.sh b/scripts/generate_BUFSIZ.sh index 750fedbef..844261906 100755 --- a/scripts/generate_BUFSIZ.sh +++ b/scripts/generate_BUFSIZ.sh @@ -6,6 +6,7 @@ . ./.config || exit 1 debug=false +#debug=true postcompile=false test x"$1" = x"--post" && { postcompile=true; shift; } @@ -62,6 +63,11 @@ generate_malloc_and_exit() { $exitcmd } +round_down_COMMON_BUFSIZE() { + COMMON_BUFSIZE=$(( ($1-32) & 0xfffffe0 )) + COMMON_BUFSIZE=$(( COMMON_BUFSIZE < 1024 ? 1024 : COMMON_BUFSIZE )) +} + # User does not want any funky stuff? test x"$CONFIG_FEATURE_USE_BSS_TAIL" = x"y" || generate_std_and_exit @@ -102,22 +108,43 @@ if $postcompile; then # How much space between _end[] and next page? PAGE_MASK=$((PAGE_SIZE-1)) - COMMON_BUFSIZE=$(( (-END) & PAGE_MASK )) - echo "COMMON_BUFSIZE = $COMMON_BUFSIZE bytes" + TAIL_SIZE=$(( (-END) & PAGE_MASK )) + $debug && echo "TAIL_SIZE:$TAIL_SIZE bytes" - if test x"$method" != x"malloc"; then - if test $COMMON_BUFSIZE -lt 1024; then + if test x"$method" = x"1k" || test x"$method" = x"big"; then + if test $TAIL_SIZE -lt 1024; then # _end[] has no enough space for bb_common_bufsiz1[] + echo "Warning! Space in _end[] is too small ($TAIL_SIZE bytes)!" + echo "Rerun make to build a binary which doesn't use it!" rm -- "$common_bufsiz_h.1k.OK" 2>/dev/null { md5sum <.config | cut -d' ' -f1; stat -c "%Y" .config; } >"$common_bufsiz_h.1k.FAIL" - echo "Warning! Space in _end[] is too small ($COMMON_BUFSIZE bytes)!" - echo "Rerun make to build a binary which doesn't use it!" - rm busybox_unstripped busybox + rm busybox_unstripped busybox 2>/dev/null +# Note: here we can do either a "malloc" or "std" build. +# "malloc" gives a bit bigger code: +# text bss filename +# 804355 5385 busybox.std +# 804618 4361 busybox.malloc +# but may have a smaller .bss (not guaranteed!). Use "pmap -x" to verify. exitcmd="exit 1" + generate_malloc_and_exit else + PREV_SIZE=1024 + test x"$method" = x"big" && PREV_SIZE=`cat -- "$common_bufsiz_h.1k.OK"` + round_down_COMMON_BUFSIZE $PREV_SIZE + PREV_BUFSIZE=$COMMON_BUFSIZE + rm -- "$common_bufsiz_h.1k.FAIL" 2>/dev/null - echo $COMMON_BUFSIZE >"$common_bufsiz_h.1k.OK" - test $COMMON_BUFSIZE -gt $((1024+32)) && echo "Rerun make to use larger COMMON_BUFSIZE" + echo $TAIL_SIZE >"$common_bufsiz_h.1k.OK" + round_down_COMMON_BUFSIZE $TAIL_SIZE + # emit message only if COMMON_BUFSIZE is indeed larger + test $COMMON_BUFSIZE -gt $PREV_BUFSIZE \ + && echo "Rerun make to use larger COMMON_BUFSIZE ($COMMON_BUFSIZE)" +#TODO: test $PREV_BUFSIZE -lt $TAIL_SIZE && PANIC!!! +#Code size with COMMON_BUFSIZE > 1024 may be bigger than code with COMMON_BUFSIZE = 1024! +#(currently we just hope "-32 and round down to 32" saves us) + + test $COMMON_BUFSIZE = 1024 && generate_1k_and_exit + generate_big_and_exit $COMMON_BUFSIZE "big" fi fi fi @@ -127,13 +154,12 @@ fi if test -f "$common_bufsiz_h.1k.OK"; then # Previous build succeeded fitting 1k into _end[]. # Try bigger COMMON_BUFSIZE if possible. - COMMON_BUFSIZE=`cat -- "$common_bufsiz_h.1k.OK"` - # Round down a bit - COMMON_BUFSIZE=$(( (COMMON_BUFSIZE-32) & 0xfffffe0 )) - COMMON_BUFSIZE=$(( COMMON_BUFSIZE < 1024 ? 1024 : COMMON_BUFSIZE )) + TAIL_SIZE=`cat -- "$common_bufsiz_h.1k.OK"` + round_down_COMMON_BUFSIZE $TAIL_SIZE test $COMMON_BUFSIZE = 1024 && generate_1k_and_exit generate_big_and_exit $COMMON_BUFSIZE "big" fi + if test -f "$common_bufsiz_h.1k.FAIL"; then # Previous build FAILED to fit 1k into _end[]. # Was it with same .config? @@ -142,6 +168,7 @@ if test -f "$common_bufsiz_h.1k.FAIL"; then # If yes, then build a "malloced" version if test x"$oldcfg" = x"$curcfg"; then echo "Will not try 1k build, it failed before. Touch .config to override" +# Note: here we can do either a "malloc" or "std" build. generate_malloc_and_exit fi # else: try 1k version @@ -149,5 +176,6 @@ if test -f "$common_bufsiz_h.1k.FAIL"; then rm -- "$common_bufsiz_h.1k.FAIL" generate_1k_and_exit fi + # There was no 1k build yet. Try it. generate_1k_and_exit -- cgit v1.2.3-55-g6feb