From: Peter Zijlstra <peterz@infradead.org>
To: Mathieu Desnoyers <compudj@krystal.dyndns.org>
Cc: Masami Hiramatsu <mhiramat@redhat.com>,
Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
Fr??d??ric Weisbecker <fweisbec@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
lkml <linux-kernel@vger.kernel.org>,
systemtap <systemtap@sources.redhat.com>,
DLE <dle-develop@lists.sourceforge.net>,
Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
Jim Keniston <jkenisto@us.ibm.com>
Subject: Re: [PATCH tracing/kprobes] kprobes: Disable booster when CONFIG_PREEMPT=y
Date: Fri, 29 Jan 2010 18:15:38 +0100 [thread overview]
Message-ID: <1264785338.24455.14.camel@laptop> (raw)
In-Reply-To: <20100129170817.GA2283@Krystal>
On Fri, 2010-01-29 at 12:08 -0500, Mathieu Desnoyers wrote:
>
> 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 ?
PREEMPT_ACTIVE does that:
preempt_schedule()
add_preempt_count(PREEMPT_ACTIVE);
schedule();
schedule()
if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
if (unlikely(signal_pending_state(prev->state, prev)))
prev->state = TASK_RUNNING;
else
deactivate_task(rq, prev, 1);
switch_count = &prev->nvcsw;
}
next prev parent reply other threads:[~2010-01-29 17:16 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-22 1:16 [RFC PATCH 00/10] Ftrace functions hashlist Frederic Weisbecker
2010-01-22 1:16 ` [RFC PATCH 01/10] ftrace: Generalize the function hashlist from function profiler Frederic Weisbecker
2010-01-22 1:16 ` [RFC PATCH 02/10] ftrace: Ensure tracing has really stopped before leaving unregister_ftrace_graph Frederic Weisbecker
2010-01-22 1:51 ` Steven Rostedt
2010-01-22 2:04 ` Frederic Weisbecker
2010-01-22 1:16 ` [RFC PATCH 03/10] ftrace: Drop the ftrace_profile_enabled checks in tracing hot path Frederic Weisbecker
2010-01-22 2:05 ` Steven Rostedt
2010-01-22 2:28 ` Mathieu Desnoyers
2010-01-22 3:12 ` Steven Rostedt
2010-01-22 4:09 ` Mathieu Desnoyers
2010-01-22 4:52 ` Steven Rostedt
2010-01-22 12:34 ` Mathieu Desnoyers
2010-01-22 14:54 ` Masami Hiramatsu
2010-01-25 20:58 ` Frederic Weisbecker
2010-01-25 22:14 ` Masami Hiramatsu
2010-01-26 0:41 ` Frederic Weisbecker
2010-01-26 1:13 ` Mathieu Desnoyers
2010-01-26 1:37 ` Masami Hiramatsu
2010-01-27 21:55 ` [PATCH tracing/kprobes] kprobes: Disable booster when CONFIG_PREEMPT=y Masami Hiramatsu
2010-01-28 1:08 ` Mathieu Desnoyers
2010-01-28 4:21 ` Ananth N Mavinakayanahalli
2010-01-29 9:21 ` Ingo Molnar
2010-01-29 11:30 ` Peter Zijlstra
2010-01-29 14:52 ` Masami Hiramatsu
2010-01-29 17:08 ` Mathieu Desnoyers
2010-01-29 17:15 ` Peter Zijlstra [this message]
2010-01-29 17:27 ` Mathieu Desnoyers
2010-01-29 17:32 ` Masami Hiramatsu
2010-01-22 2:43 ` [RFC PATCH 03/10] ftrace: Drop the ftrace_profile_enabled checks in tracing hot path Frederic Weisbecker
2010-01-22 3:05 ` Steven Rostedt
2010-01-25 20:52 ` Frederic Weisbecker
2010-01-22 1:16 ` [RFC PATCH 04/10] ftrace: Ensure buffers are visibles to tracing callbacks right away Frederic Weisbecker
2010-01-22 1:16 ` [RFC PATCH 05/10] ftrace: Drop buffer check in function profiler callbacks Frederic Weisbecker
2010-01-25 6:17 ` Lai Jiangshan
2010-01-30 20:47 ` Frederic Weisbecker
2010-01-22 1:16 ` [RFC PATCH 06/10] ftrace: Release the function hlist if we don't need it anymore Frederic Weisbecker
2010-01-25 6:41 ` Lai Jiangshan
2010-01-30 21:14 ` Frederic Weisbecker
2010-01-22 1:16 ` [RFC PATCH 07/10] ftrace: Make the function hashlist concurrently usable Frederic Weisbecker
2010-01-22 1:16 ` [PATCH 08/10] tracing: Simplify test for function_graph tracing Frederic Weisbecker
2010-01-22 1:16 ` [RFC PATCH 09/10] tracing: Use the hashlist for graph function Frederic Weisbecker
2010-01-25 8:50 ` Lai Jiangshan
2010-01-30 21:19 ` Frederic Weisbecker
2010-01-22 1:16 ` [RFC PATCH 10/10] ftrace: Factorize search and insertion in the function hashlist Frederic Weisbecker
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