On Wed, Nov 2, 2011 at 7:49 AM, Premi, Sanjeev premi@ti.com wrote:
-----Original Message----- From: u-boot-bounces@lists.denx.de [mailto:u-boot-bounces@lists.denx.de] On Behalf Of Wolfgang Denk Sent: Wednesday, November 02, 2011 12:24 PM To: u-boot@lists.denx.de Cc: Graeme Russ; Kumar Gala; Albert Aribaud; Andy Fleming Subject: [U-Boot] [PATCH] Reduce build times
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 Denk wd@denx.de Cc: Andy Fleming afleming@gmail.com Cc: Kumar Gala galak@kernel.crashing.org Cc: Albert Aribaud albert.aribaud@free.fr cc: Graeme Russ graeme.russ@gmail.com cc: Mike Frysinger vapier@gentoo.org
Results for OMAP3EVM. (Tried 5 times just to be sure as I see >50% reduction.)
Before After ------ ------ real 109.03 49.78 user 71.43 29.06 sys 26.83 7.66
Over here omap3_evm wall-clock time on make -j12 goes from 27sec to 10sec.