twx-linux/include
Andrea Parri dbb92f8864 workqueue: Document (some) memory-ordering properties of {queue,schedule}_work()
It's desirable to be able to rely on the following property:  All stores
preceding (in program order) a call to a successful queue_work() will be
visible from the CPU which will execute the queued work by the time such
work executes, e.g.,

  { x is initially 0 }

    CPU0                              CPU1

    WRITE_ONCE(x, 1);                 [ "work" is being executed ]
    r0 = queue_work(wq, work);          r1 = READ_ONCE(x);

  Forbids: r0 == true && r1 == 0

The current implementation of queue_work() provides such memory-ordering
property:

  - In __queue_work(), the ->lock spinlock is acquired.

  - On the other side, in worker_thread(), this same ->lock is held
    when dequeueing work.

So the locking ordering makes things work out.

Add this property to the DocBook headers of {queue,schedule}_work().

Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-02-12 15:59:40 -05:00
..
acpi
asm-generic Microblaze patches for 5.6-rc1 2020-02-04 11:58:07 +00:00
clocksource
crypto
drm
dt-bindings ARM: SoC: late updates 2020-02-08 14:17:27 -08:00
keys
kunit
kvm
linux workqueue: Document (some) memory-ordering properties of {queue,schedule}_work() 2020-02-12 15:59:40 -05:00
math-emu
media
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net bonding/alb: properly access headers in bond_alb_xmit() 2020-02-05 14:28:09 +01:00
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rdma RDMA/core: Make the entire API tree static 2020-01-30 16:28:52 -04:00
scsi
soc ARM: SoC-related driver updates 2020-02-08 14:04:19 -08:00
sound ARM: Device-tree updates 2020-02-08 13:58:44 -08:00
target
trace ARM: SoC-related driver updates 2020-02-08 14:04:19 -08:00
uapi fs: New zonefs file system 2020-02-09 15:51:46 -08:00
vdso
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xen xen: branch for v5.6-rc1 2020-02-05 17:44:14 +00:00