did you run YAFU task in the past and got totally P.O. because it took over your whole host?
now with the new updated beta version of boinc, the app_config.xml will let you max out the number of cpu/cores/threads that an mt task will take over. missing deadline on gpu task, ST tasks running high Pri. not letting your mt tasks run?
I've been testing this out for a few days now and it is working for me. YMMV.
it works for other projects also on their MT tasks..
I was never able to get it to work before this version of boinc.


download boinc version 7.2.39, it's beta but works..
install.
create the following app_config.xml in the yafu directory. use text editor
this will over ride using up all of the cores.in this case it limits the number of threads to 2. so it does not keep your gpu projects apps from running or other ST apps from other projects that are getting close to deadline...
it also lets you run more than one yafu task at a time.
I did not come up with this, found it over on MW@H, a great big thank you to the person that posted it over on MW@H.. after you create the app_config.xml you will need to stop the BOINC client and restart for it to take effect...

<!-- YAFU -->
<app_config>
<!-- YAFU -->
<!-- YAFU -->
<app_version>
<app_name>yafu</app_name>
<plan_class>mt</plan_class>
<avg_ncpus>2</avg_ncpus>
<cmdline>--nthreads 2</cmdline>
</app_version>
</app_config>

and in case your wondering if you change that app_config.xml to the following it will run like a ST task. just remember that when the yafu-x64-13401.exe is running ( that is on a 64 bit windows host) it will still try and use all of the cores, but that is for very short times, the avg_ncups and --nthreads part control the number of copies of the ecm and gnfs that it will start..

<!-- YAFU -->
<app_config>
<!-- YAFU -->
<!-- YAFU -->
<app_version>
<app_name>yafu</app_name>
<plan_class>mt</plan_class>
<avg_ncpus>1</avg_ncpus>
<cmdline>--nthreads 1</cmdline>
</app_version>
</app_config>