Hi Chris,
On Oct 23, 2012, at 11:39 PM, Chris Tapp opensou...@keylevel.com wrote:
On 23 Oct 2012, at 19:45, Elvis Dowson wrote:
I noticed that between commits
http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=0260bb5c6978839c068007fcff2f704937805faf
and
http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=a3d5e9e6b7729319c518dcaf25bbe0643bfb25db
the build time has improved by around 7 minutes for my machine
configuration, for building a core-image-minimal rootfs for the Xilinx
ZC-702 FPGA with dual ARM Cortex A-9 CPUs.
commit id 0260bb5c6978839c068007fcff2f704937805faftook 29 minutes
commit id a3d5e9e6b7729319c518dcaf25bbe0643bfb25db took 22 minutes
The machine configuration is an Intel i7 3770K over-clocked to 4.2GHz, with
16GB RAM at 1600Mhz, two 120GB SSDs configured into a striped disk array
(Intel 330 series SSDs) with a write performance of 838MB/s and read
performance of around 600MB/s, in RAID0 configuration, with a Corsair HT100
liquid CPU cooler keeping the CPU cool at around 52 degree centigrade during
the build process. The motherboard is a gigabyte GA-Z77X-UP5TH
http://www.gigabyte.com/products/product-page.aspx?pid=4279#ov
This motherboard has a thunderbolt display port, so I can re-use my existing
Apple Thunderbolt display. I've run Ubuntu 12.04.1 LTS and Ubuntu 12.10, and
it appears to work after a few tweaks.
The only curious thing that I've noticed is that I don't see a large
performance improvement using a standard 3TB Seagate Barracuda 7200 RPM HDD,
and the two Intel Series 330 SSDs in a striped RAID0 configuration. The read
(600MB/s) / write (838MB/s) figures are impressive, although I expected the
read performance to be higher than write performance, as is normally with a
single SSD. I'm using the motherboard's hardware RAID support on a 6GB/s
SATA 3 port.
The 3TB HDD took the approximately 2 or 3 minutes longer than the 120GB x 2
RAID0 SSD configuration for commit id
0260bb5c6978839c068007fcff2f704937805faf (31 minutes vs. 29 minutes).
My local.conf parallelism settings were set to 6 threads for bitbake and
make, for the quad-core (virtual 8 cpu cores)system.
Has anyone tried yocto builds with a 6-core, 8-core or 10-core Xeon
processor system? How do those figures fare? I'm thinking my current
bottleneck might be the CPU and not the HDD (?!), for the yocto build
workloads, which I find curious and would like to confirm.
I did quite a bit of experimenting with this a while back (similar spec, but
with nearly 1000MB/s read/write SDD array). CPU was quad core with
hyper-threading, so 8 virtual cores. I generally run with 16 threads, 16
parallel make as I find that the main performance hit is running out of stuff
to keep all the cores busy.
Most of the time all 8 cores are maxed out, but around when the kernel gets
built (and cross tools needed for it) I see the total CPU use drop to about
25%. This isn't because the system is I/O bound; it simply doesn't have
enough tasks ready to run at that point in time.
I estimate that my 55 min build times would come down by 10 to 15 minutes if
I could keep the CPUs busy (still, much better than the 10 hour build times
on my previous system!).
With the poky/master branch commit 33440ee70623394d06a4b214c2be10788cba6d08,
which is the tip master branch, I tried two builds
01. parallelism set to 16, which took 23 minutes 21 seconds.
02. parallelism set to 6, which took less time at 22 minutes 13 seconds.
Therefore, for a quad core machine (Intel i7-3770K @ 4.2GHz over-clocked, 16GB
1600MHz RAM), setting the parallelism parameters to 6 appears to be better than
setting it to 16.
Run # 01
BB_NUMBER_THREADS = 16
PARALLEL_MAKE = -j 16
Build Configuration:
BB_VERSION= 1.16.0
TARGET_ARCH = arm
TARGET_OS = linux-gnueabi
MACHINE = zynq-zc702
DISTRO= poky
DISTRO_VERSION= 1.3+snapshot-20121025
TUNE_FEATURES = armv7a vfp neon cortexa9
TARGET_FPU= vfp-neon
meta
meta-yocto= master:33440ee70623394d06a4b214c2be10788cba6d08
toolchain-layer = master:55855cd569fbff7182974ca08b1de8435bf0f597
meta-zynq-balister =
master-xilinx-zc702-gcc-4.7:d168cea411034d1f1530e4eacf6eb3ce4affd1c8
NOTE: Resolving any missing task queue dependencies
NOTE: Preparing runqueue
NOTE: Executing SetScene Tasks
NOTE: Executing RunQueue Tasks
NOTE: validating kernel configuration
cat: meta/cfg/standard/zynq-zc702/specified.cfg: No such file or directory
cat: meta/cfg/standard/zynq-zc702/specified.cfg: No such file or directory
** NOTE: There were 0 required options requested that do not
have a corresponding value present in the final .config file.
This is a violation of the policy defined by the higher level config
The full list can be found in your kernel src dir at:
meta/cfg/standard/zynq-zc702/missing_required.cfg
