linux/include
Thomas Gleixner 1cf12e08bc sched/hotplug: Consolidate task migration on CPU unplug
With the new mechanism which kicks tasks off the outgoing CPU at the end of
schedule() the situation on an outgoing CPU right before the stopper thread
brings it down completely is:

 - All user tasks and all unbound kernel threads have either been migrated
   away or are not running and the next wakeup will move them to a online CPU.

 - All per CPU kernel threads, except cpu hotplug thread and the stopper
   thread have either been unbound or parked by the responsible CPU hotplug
   callback.

That means that at the last step before the stopper thread is invoked the
cpu hotplug thread is the last legitimate running task on the outgoing
CPU.

Add a final wait step right before the stopper thread is kicked which
ensures that any still running tasks on the way to park or on the way to
kick themself of the CPU are either sleeping or gone.

This allows to remove the migrate_tasks() crutch in sched_cpu_dying(). If
sched_cpu_dying() detects that there is still another running task aside of
the stopper thread then it will explode with the appropriate fireworks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102346.547163969@infradead.org
2020-11-10 18:38:58 +01:00
..
acpi pci-v5.10-changes 2020-10-22 12:41:00 -07:00
asm-generic vmlinux.lds.h: Keep .ctors.* with .ctors 2020-10-27 11:13:41 -07:00
clocksource
crypto
drm sound updates for 5.10 2020-10-15 11:07:44 -07:00
dt-bindings ARM: Devicetree updates 2020-10-24 10:44:18 -07:00
keys
kunit treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
kvm ARM: 2020-10-23 11:17:56 -07:00
linux sched/hotplug: Consolidate task migration on CPU unplug 2020-11-10 18:38:58 +01:00
math-emu
media ARM: SoC platform updates 2020-10-24 10:33:08 -07:00
memory
misc
net Fixes for 5.10-rc1 from the networking tree: 2020-10-23 12:05:49 -07:00
pcmcia
ras mm,hwpoison: introduce MF_MSG_UNSPLIT_THP 2020-10-16 11:11:17 -07:00
rdma RDMA: Explicitly pass in the dma_device to ib_register_device 2020-10-16 13:53:46 -03:00
scsi SCSI misc on 20201023 2020-10-23 16:19:02 -07:00
soc ARM: SoC-related driver updates 2020-10-24 10:39:22 -07:00
sound
target
trace treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
uapi A single fix to compute the field offset of the SNOOPX bit in the data 2020-10-25 11:22:59 -07:00
vdso
video
xen xen: branch for v5.10-rc1c 2020-10-25 10:55:35 -07:00