Messages in this thread | | | Date | Fri, 29 Jan 2010 09:52:13 -0500 | From | Masami Hiramatsu <> | Subject | Re: [PATCH tracing/kprobes] kprobes: Disable booster when CONFIG_PREEMPT=y |
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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.
Thank you,
-- Masami Hiramatsu
Software Engineer Hitachi Computer Products (America), Inc. Software Solutions Division
e-mail: mhiramat@redhat.com
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