Commit Graph

5 Commits

Author SHA1 Message Date
Denys Vlasenko
ca9c4653a9 libbb: add sanity check in bb_arg_max()
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2014-12-24 01:46:29 +01:00
Denys Vlasenko
04c1417602 libbb: use ARG_MAX for bb_arg_max() only if it's 60k+
Sometimes ARG_MAX is small (like 32k) yet sysconf(_SC_ARG_MAX)
is big, and people prefer using the bigger value.

OTOH, with sufficiently large ARG_MAX, further wins from
sysconf(_SC_ARG_MAX) being bigger are exponentially smaller:
you can see 4 times fewer fork+execs when you run find, but
when each execed process already takes a thousand parameters
it's likely execution time is dominated by what that process
does with each parameter.

Thus, with this change ARG_MAX is used if it's sufficiently big,
otherwise sysconf(_SC_ARG_MAX) is used.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2014-11-26 15:17:59 +01:00
Denys Vlasenko
5aeae36e2b libbb: fix compile failure if both ARG_MAX and _SC_ARG_MAX are defined
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2014-06-25 15:39:27 +02:00
Bartosz Golaszewski
5d2e409ef8 libbb: use a wrapper around sysconf(_SC_CLK_TCK) to save a few bytes
function                                             old     new   delta
bb_sc_clk_tck                                          -      10     +10
timescmd                                             118     113      -5
print_route                                         1763    1758      -5
mpstat_main                                         1288    1283      -5
iostat_main                                         1947    1942      -5
INET_setroute                                        879     871      -8
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/5 up/down: 10/-28)            Total: -18 bytes
Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2014-06-22 14:01:13 +02:00
Denys Vlasenko
f92f1d0181 find: use sysconf(_SC_ARG_MAX) to determine the command-line size limit
The find utility uses a hardcoded value of 32 * 1024 as the limit of
the command-line length when calling 'find -exec ... {} +'. This results
in over 4 times more execve() calls than in coreutils' find.

This patch uses the limit defined in system headers.

Based on the patch by  Bartosz Golaszewski <bartekgola@gmail.com>.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2014-06-22 13:54:40 +02:00