Commit Graph

20 Commits

Author SHA1 Message Date
Denys Vlasenko
dd02a05e08 build system: finer-grained selection of search speedup table.
KNOWN_APPNAME_OFFSETS=8 versus KNOWN_APPNAME_OFFSETS=0:

function                                             old     new   delta
find_applet_by_name                                   55     136     +81
applet_nameofs                                         -      14     +14
run_applet_and_exit                                  757     758      +1

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2016-04-02 15:18:26 +02:00
Ron Yorston
610c4c385b applet_tables: save space by removing applet name offsets
The array applet_nameofs consumes two bytes per applet.  It encodes

   nofork/noexec flags
   suid flags
   the offset of the applet name in the applet_name string

Change the applet_table build tool to store the flags in two separate
arrays (applet_flags and applet_suid).  Replace applet_nameofs[] with a
smaller version that only stores a limited number of offsets.

This requires changes to the macros APPLET_IS_NOFORK, APPLET_IS_NOEXEC
and APPLET_SUID.

   According to Valgrind the original find_applet_by_name required
   353 cycles per call, averaged over all names.  Adjusting the number
   of known offsets allows space to be traded off against execution time:

      KNOWN_OFFSETS     cycles     bytes (wrt KNOWN_OFFSETS = 0)

           0             9057        -
           2             4604       32
           4             2407       75
           8             1342       98
          16              908      130
          32              884      194

   This patch uses KNOWN_OFFSETS = 8.

v2:
   Remove some dead code from the applet_table tool;
   Treat the applet in the middle of the table as a special case.

v3:
   Use the middle applet to adjust the start of the linear search as
   well as the last applet found.

v4:
   Use an augmented linear search in find_applet_by_name.
   Drop the special treatment of the middle name from get_applet_name:
   most of the advantage now derives from the last stored value.

v5:
   Don't store index in applet_nameofs, it can be calculated.

v6:
   Tweaks by Denys

function                                             old     new   delta
find_applet_by_name                                   25     125    +100
applet_suid                                            -      92     +92
run_applet_no_and_exit                               452     460      +8
run_applet_and_exit                                  695     697      +2
applet_name_compare                                   31       -     -31
applet_nameofs                                       734      14    -720
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 3/1 up/down: 202/-751)         Total: -549 bytes
   text       data        bss        dec        hex    filename
 925464        906      17160     943530      e65aa    busybox_old
 924915        906      17160     942981      e6385    busybox_unstripped

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2016-03-30 00:44:11 +02:00
Denys Vlasenko
cd7a38a87d false: make "false --help" exit with 1
function                                             old     new   delta
run_applet_no_and_exit                               447     445      -2

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2014-09-18 00:47:05 +02:00
Denys Vlasenko
924a179cb7 build system: do not generate MAX_APPLET_NAME_LEN (unused)
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2013-11-26 12:03:24 +01:00
Denys Vlasenko
78a3b6739c Fix one-applet build for tcpsvd
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2012-03-19 04:38:00 +01:00
Denys Vlasenko
6d2d652cd3 applet_tables: fix single applet build failure. Closes 4009
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2011-09-16 14:28:32 +02:00
Denys Vlasenko
6ec1510f71 applet_tables: do not include libbb.h, that header ir for target builds
...and applets/applet_tables.c is built on *host*.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2011-03-28 01:23:38 +02:00
Denys Vlasenko
0ef64bdb40 *: make GNU licensing statement forms more regular
This change retains "or later" state! No licensing _changes_ here,
only form is adjusted (article, space between "GPL" and "v2" and so on).

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-08-16 20:14:46 +02:00
Denys Vlasenko
9768a82eb0 *: fix "see file License ..." - the file is named LICENSE (in uppercase)
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-08-16 03:04:14 +02:00
Denys Vlasenko
1fcbff2fac build system: do not rebuild ash and hush on any change to any .c file
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-06-26 02:40:08 +02:00
Denys Vlasenko
1497484839 ash,hush: make it possible to build them individually
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-03-23 01:08:26 +01:00
Denys Vlasenko
acabf8fcb8 Update documentation generator so that it sucks less
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2009-10-02 01:10:32 +02:00
Denis Vlasenko
79cedcb2c0 Avoid linking in printf/bsearch if possible. -20k for static bbox with
"basename", "true" and "false" only.

function                                             old     new   delta
full_write2_str                                        -      25     +25
bb_show_usage                                        183     202     +19
main                                                 883     898     +15
run_applet_and_exit                                  501     507      +6
2008-04-08 21:13:28 +00:00
Denis Vlasenko
468aea2d88 shells: do not frocibly enable test, echo and kill _applets_,
just build relevant source and use xxx_main functions.
build system: add a special case when we have exactly one applet enabled
(makes "true", "false", "basename" REALLY tiny).
getopt32: do not use stdio.

function                                             old     new   delta
getopt32                                            1385    1412     +27
make_device                                         1187    1200     +13
basename_main                                        120     127      +7
tcpudpsvd_main                                      1922    1926      +4
testcmd                                                5       -      -5
echocmd                                                5       -      -5
fuser_main                                          1243    1231     -12
------------------------------------------------------------------------------
(add/remove: 0/2 grow/shrink: 4/1 up/down: 51/-22)             Total: 29 bytes
2008-04-01 14:47:57 +00:00
Denis Vlasenko
32b2a9fd6a small code readability and typo fixes 2008-02-22 22:43:22 +00:00
Denis Vlasenko
5fee2e1a79 ps: add conditional support for -o [e]time 2008-01-05 03:26:41 +00:00
Denis Vlasenko
9cd30d30a0 Makefile.help: removing allbareconfig target from help
applet_tables: fix allnoconfig
2008-01-04 20:10:51 +00:00
Denis Vlasenko
f7be20e70c nameif: extended matching (Nico Erfurth <masta@perlgolf.de>)
*: whitespace fixes

function                                             old     new   delta
prepend_new_eth_table                                  -     304    +304
nameif_main                                          620     684     +64
cc_macaddr                                            51       -     -51
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 1/0 up/down: 368/-51)           Total: 317 bytes
2007-12-24 14:09:19 +00:00
Denis Vlasenko
745cd17926 Further optimize applet tables; prettify build output
text    data     bss     dec     hex filename
 775923     929    9100  785952   bfe20 busybox_old
 775565     929    9100  785594   bfcba busybox_unstripped
2007-11-29 03:31:20 +00:00
Denis Vlasenko
41f5add965 forgotten part of previous commit 2007-11-28 06:49:42 +00:00