Date: Fri, 29 Jan 2010 10:21:35 +0100
From: Ingo Molnar <mingo@elte.hu>
To: Masami Hiramatsu <mhiramat@redhat.com>,
       Thomas Gleixner <tglx@linutronix.de>,
       Peter Zijlstra <a.p.zijlstra@chello.nl>,
       Fr??d??ric Weisbecker <fweisbec@gmail.com>,
       Steven Rostedt <rostedt@goodmis.org>
Cc: lkml <linux-kernel@vger.kernel.org>,
       systemtap <systemtap@sources.redhat.com>,
       DLE <dle-develop@lists.sourceforge.net>,
       Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
       Frederic Weisbecker <fweisbec@gmail.com>,
       Jim Keniston <jkenisto@us.ibm.com>,
       Mathieu Desnoyers <compudj@krystal.dyndns.org>,
       Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH tracing/kprobes] kprobes: Disable booster when
 CONFIG_PREEMPT=y
Message-ID: <20100129092135.GE10878@elte.hu>
References: <4B5E476C.9030303@redhat.com>
 <20100127215531.24775.26807.stgit@dhcp-100-2-132.bos.redhat.com>
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* 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?

	Ingo
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