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From: Masami Hiramatsu on 29 Jan 2010 10:00
Ingo Molnar wrote:
>
> * Masami Hiramatsu <mhiramat(a)redhat.com> wrote:
>
>> Disable kprobe booster when CONFIG_PREEMPT=y, because it can't ensure that
>> all kernel threads preempted on kprobe's boosted slot run out from the slot
>> even using freeze_processes().
>
> hm, this really sucks as it makes preemptible kernels perform worse. Is there
> no better solution?
>
>> The booster on preemptive kernel will be resumed if synchronize_tasks() or
>> something like that is introduced.
>
> such as this one?

Yes, I think this synchronize_tasks(), which just (sleeping) wait until
all currently preempted tasks are wake up and scheduled, can ensure safety.

Thank you,

--
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division

e-mail: mhiramat(a)redhat.com

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Prev: USB mass storage and ARM cache coherency
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