linux-brain/include
Peter Zijlstra 5b1e4fc298 kthread: Extract KTHREAD_IS_PER_CPU
[ Upstream commit ac687e6e8c26181a33270efd1a2e2241377924b0 ]

There is a need to distinguish geniune per-cpu kthreads from kthreads
that happen to have a single CPU affinity.

Geniune per-cpu kthreads are kthreads that are CPU affine for
correctness, these will obviously have PF_KTHREAD set, but must also
have PF_NO_SETAFFINITY set, lest userspace modify their affinity and
ruins things.

However, these two things are not sufficient, PF_NO_SETAFFINITY is
also set on other tasks that have their affinities controlled through
other means, like for instance workqueues.

Therefore another bit is needed; it turns out kthread_create_per_cpu()
already has such a bit: KTHREAD_IS_PER_CPU, which is used to make
kthread_park()/kthread_unpark() work correctly.

Expose this flag and remove the implicit setting of it from
kthread_create_on_cpu(); the io_uring usage of it seems dubious at
best.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103506.557620262@infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-02-07 15:35:49 +01:00
..
acpi PM: ACPI: PCI: Drop acpi_pm_set_bridge_wakeup() 2020-12-30 11:51:32 +01:00
asm-generic arm64: make atomic helpers __always_inline 2021-01-27 11:47:44 +01:00
clocksource
crypto crypto: algif_aead - Only wake up when ctx->more is zero 2020-08-21 13:05:30 +02:00
drm iommu/vt-d: Move intel_iommu_gfx_mapped to Intel IOMMU header 2020-11-24 13:29:17 +01:00
dt-bindings clk: imx8mn: Fix incorrect clock defines 2020-03-18 07:17:55 +01:00
keys KEYS: Don't write out to userspace while holding key semaphore 2020-04-23 10:36:45 +02:00
kvm
linux kthread: Extract KTHREAD_IS_PER_CPU 2021-02-07 15:35:49 +01:00
math-emu
media media: v4l2-fwnode: Return -EINVAL for invalid bus-type 2020-12-30 11:51:08 +01:00
misc
net tcp: make TCP_USER_TIMEOUT accurate for zero window probes 2021-02-07 15:35:47 +01:00
pcmcia
ras
rdma RDMA/umem: Fix signature of stub ib_umem_find_best_pgsz() 2020-10-29 09:57:47 +01:00
scsi scsi: libiscsi: Fix NOP race condition 2020-12-02 08:49:49 +01:00
soc irqchip/eznps: Fix build error for !ARC700 builds 2020-09-17 13:47:47 +02:00
sound ALSA: hda: fix jack detection with Realtek codecs when in D3 2020-10-29 09:57:25 +01:00
target scsi: target: fix hang when multiple threads try to destroy the same iscsi session 2020-04-21 09:05:04 +02:00
trace writeback: Drop I_DIRTY_TIME_EXPIRE 2021-01-30 13:54:11 +01:00
uapi ICMPv6: Add ICMPv6 Parameter Problem, code 3 definition 2021-02-03 23:25:55 +01:00
vdso
video
xen xen: Fix event channel callback via INTX/GSI 2021-01-27 11:47:44 +01:00