path: root/kernel/cpu.c
diff options
authorPeter Zijlstra (Intel) <peterz@infradead.org>2016-03-10 12:54:08 +0100
committerThomas Gleixner <tglx@linutronix.de>2016-05-06 14:58:22 +0200
commite9d867a67fd03ccc07248ca4e9c2f74fed494d5b (patch)
treebd1e01ee5b5581203d3fa8397fd863c400cea2bc /kernel/cpu.c
parent04974df8049fc4240d22759a91e035082ccd18b4 (diff)
sched: Allow per-cpu kernel threads to run on online && !active
In order to enable symmetric hotplug, we must mirror the online && !active state of cpu-down on the cpu-up side. However, to retain sanity, limit this state to per-cpu kthreads. Aside from the change to set_cpus_allowed_ptr(), which allow moving the per-cpu kthreads on, the other critical piece is the cpu selection for pinned tasks in select_task_rq(). This avoids dropping into select_fallback_rq(). select_fallback_rq() cannot be allowed to select !active cpus because its used to migrate user tasks away. And we do not want to move user tasks onto cpus that are in transition. Requested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Thomas Gleixner <tglx@linutronix.de> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Jan H. Schönherr <jschoenh@amazon.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160301152303.GV6356@twins.programming.kicks-ass.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/cpu.c')
0 files changed, 0 insertions, 0 deletions