Hi Andy / Tom,
On Wed, Oct 31, 2012 at 9:17 PM, Andy Fleming afleming@gmail.com wrote:
On Wed, Oct 31, 2012 at 8:18 PM, Tom Rini trini@ti.com wrote:
On Wed, Oct 31, 2012 at 05:11:51PM -0700, Simon Glass wrote:
[snip]
Also rather than running with 'make -j40' or whatever, it uses 'make -j1' but with 40 threads. This increases CPU utilisation quite substantially (almost 50%) - I think this was discussed some time ago,
MAKEALL supports this, but doesn't default to it, today. I'm wondering if we ought to make it the default for all non-single board builds. The winning point is right around boards-to-build == `grep -c processor /proc/cpuinfo` and I think is right around setting NBUILDS to that value, both on consumer multicore and heavy-duty 32/64 core boxes.
Yeah, I usually set BUILD_NBUILDS to 24-50 on my 24-thread system, and then set BUILD_NCPUS to 1-4. It's nice to offer a little bit of parallelism on the individual builds, sometimes. I did a bunch of tests, but not in a scientific fashion. Enough to agree with you that maxing out builds seems to win for u-boot.
As a bit of an unscientific test, what sort of time does it take to build all 1000-or-so boards on your systems?
Andy
Regards, Simon