On Thu, Sep 17, 2015 at 11:52:45AM -0400, Tejun Heo wrote:

Hello,

On Thu, Sep 17, 2015 at 05:10:49PM +0200, Peter Zijlstra wrote:

quoted

Subject: sched: Refuse to unplug a CPU if this will violate user task affinity

Its bad policy to allow unplugging a CPU for which a user set explicit
affinity, either strictly on this CPU or in case this was the last
online CPU in its mask.

Either would end up forcing the thread on a random other CPU, violating
the sys_sched_setaffinity() constraint.

Shouldn't this at least handle suspend differently?  Otherwise any
userland task would be able to block suspend.

It does, it will allow suspend.