linux/scripts/kconfig
Ingo Molnar b0fe551000 kconfig: improve seed in randconfig
'make randconfig' uses glibc's rand function, and the seed of
that PRNG is set via:

			srand(time(NULL));

But 'time()' only increases once every second - freezing the
randconfig result within a single second.

My Nehalem testbox does randconfig much faster than 1 second
 and i have a few scripts that do 'randconfig until condition X'
loops.

Those scripts currently waste a lot of CPU time due to randconfig
changing its seed only once per second currently.

Change the seed to be micrseconds based. (I checked the statistical
spread of the seed - the now.tv_sec*now.tv_usec multiplication
there further improves it.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Roman Zippel <zippel@linux-m68k.org>
[sam: fix for systems where usec is zero - noticed by Geert Uytterhoeven]
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2009-03-15 23:02:07 +01:00
..
lxdialog
.gitignore
check.sh
conf.c
confdata.c
expr.c
expr.h
gconf.c
gconf.glade
images.c
kconfig_load.c
kxgettext.c
lex.zconf.c_shipped
lkc_proto.h
lkc.h
Makefile
mconf.c
menu.c
POTFILES.in
qconf.cc
qconf.h
symbol.c
util.c
zconf.gperf
zconf.hash.c_shipped
zconf.l
zconf.tab.c_shipped
zconf.y