Re: +work_on_cpu-rewrite-it-to-create-a-kernel-thread-on-demand.patchadded to -mm tree

[Ingo Molnar]

* akpm@xxxxxxxxxxxxxxxxxxxx <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:

> ------------------------------------------------------
> Subject: work_on_cpu(): rewrite it to create a kernel thread on demand
> From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> 
> The various implemetnations and proposed implemetnations of work_on_cpu()
> are vulnerable to various deadlocks because they all used queues of some
> form.
> 
> Unrelated pieces of kernel code thus gained dependencies wherein if one
> work_on_cpu() caller holds a lock which some other work_on_cpu() callback
> also takes, the kernel could rarely deadlock.
> 
> Fix this by creating a short-lived kernel thread for each work_on_cpu()
> invokation.
> 
> This is not terribly fast, but the only current caller of work_on_cpu() is
> pci_call_probe().

hm, it's quite ugly as well, and wasteful with resources.

	Ingo
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