Am 02.11.2011 07:54, schrieb Wolfgang Denk:
U-Boot Makefiles contain a number of tests for compiler features etc. which so far are executed again and again. On some architectures (especially ARM) this results in a large number of calls to gcc.
This patch makes sure to run such tests only once, thus largely reducing the number of "execve" system calls.
Example: number of "execve" system calls for building the "P2020DS" (Power Architecture) and "qong" (ARM) boards, measured as: -> strace -f -e trace=execve -o /tmp/foo ./MAKEALL<board> -> grep execve /tmp/foo | wc -l
Before: After: Reduction:
P2020DS 20555 15205 -26% qong 31692 14490 -54%
As a result, built times are significantly reduced, typically by 30...50%.
Signed-off-by: Wolfgang Denkwd@denx.de Cc: Andy Flemingafleming@gmail.com Cc: Kumar Galagalak@kernel.crashing.org Cc: Albert Aribaudalbert.aribaud@free.fr cc: Graeme Russgraeme.russ@gmail.com cc: Mike Frysingervapier@gentoo.org
Nice. Some additional numbers:
zmx25: make ----------- real 1m47.546s 0m57.213s -53% user 1m39.698s 0m54.831s sys 0m24.798s 0m9.509s
zmx25: make -j2 --------------- real 0m56.791s 0m32.187s -57% user 1m38.478s 0m55.571s sys 0m24.522s 0m9.513s
Tested-by: Matthias Weisser weisserm@arcor.de
Matthias