The BIOS is now up to date:
sworddragon@ubuntu:~$ sudo dmidecode -s bios-version && sudo dmidecode -s
bios-release-date
P1.40
10/02/2013
But the bug still exists on Ubuntu 14.04 dev with linux-image-generic
3.12.0.3.5. I have also updated the testcase: It is now written in C to exclude
Python as the source of problems (compiling with "gcc -o threads ./threads.c
-lpthread") and instead of creating 2 threads it is creating the number of
online cpu cores * 2 as threads (on my processor with 6 cores 12 threads are
created) as the overhead gets much higher with more threads.
Here are the results:
Calling ./test will result in a cpu usage of ~185%/600%.
Calling taskset -c 0 ./threads will result in a cpu usage of ~30%/600%.
** Changed in: linux (Ubuntu)
Status: Incomplete => New
** Tags removed: bios-outdated-1.40
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https://bugs.launchpad.net/bugs/1073148
Title:
High cpu overhead on using multiple cores
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