Hi Andy,
Le 25/04/2012 07:33, Andy Fleming a écrit :
The MAKEALL script cleverly runs make with the appropriate options
to use all of the cores on the system, but your average U-Boot build
can't make much use of more than a few cores. If you happen to have
a many-core server, your builds will leave most of the system idle.
In order to make full use of such a system, we need to build multiple
targets in parallel, and this requires directing make output into
multiple directories. We add a BUILD_NBUILDS variable, which allows
users to specify how many builds to run in parallel.
When BUILD_NBUILDS is set greater than 1, we redefine BUILD_DIR for
each build to be ${BUILD_DIR}/${target}. Also, we make "./build" the
default BUILD_DIR when BUILD_NBUILDS is greater than 1.
MAKEALL now tracks which builds are still running, and when one
finishes, it starts a new build.
Once each build finishes, we run "make tidy" on its directory, to reduce
the footprint.
As a result, we are left with a build directory with all of the built
targets still there for use, which means anyone who wanted to use
MAKEALL as part of a test harness can now do so.
Signed-off-by: Andy Fleming<aflem...@freescale.com>
---
v2: - Update to keep BUILD_NBUILDS builds in flight, rather than batching
- Clean up style things
- Defer error output until build completion to make output *slightly*
more readable
v3: - Add BUILD_MANY variable to clarify logic
- Added comment for done/skip prefixes, and renamed for clarity
- Changed CURRENT_COUNT to CURRENT_CNT to match TOTAL_CNT
- Put build wait logic into its own manage_build function
- Used wildcards to delete build management files
- Fixed a bug where error-less builds printed an error
For ./MAKEALL arm, using cs2011-09, 7 builds 1 cpu on a 8 thread machine:
real 29m20.272s
user 95m59.708s
sys 10m17.383s
without the patch, and
real 20m26.480s
user 100m1.155s
sys 8m34.988s
with it, so there is definitely a benefit.
*However*, two boards build without and do not build clean with: scpu
and pndb3.
Also, the final report is not displayed as the same with and without the
patch -- with it, unclean boards are listed one per line, without it,
they are listed in a single line.
Last: breaking during a parallel build then trying a git clean -xfd
causes errors such as files missing.
Amicalement,
--
Albert.
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