Messages in this thread |  | | | Date | Fri, 29 Jan 2010 12:08:17 -0500 | | From | Mathieu Desnoyers <> | | Subject | Re: [PATCH tracing/kprobes] kprobes: Disable booster when CONFIG_PREEMPT=y |
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* Masami Hiramatsu (mhiramat@redhat.com) wrote: > Ingo Molnar wrote: > > > > * Masami Hiramatsu <mhiramat@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
If a task is set as stopped, and the preempted before calling schedule, can this result in a preempted task staying in that state for an arbitrary long period of time ? Or is there some mechanism prohibiting that in the scheduler ?
Thanks,
Mathieu
> > Thank you, > > -- > Masami Hiramatsu > > Software Engineer > Hitachi Computer Products (America), Inc. > Software Solutions Division > > e-mail: mhiramat@redhat.com >
-- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
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