From: Ingo Molnar <mingo@elte.hu>
To: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
Fr??d??ric Weisbecker <fweisbec@gmail.com>,
Stephen Rothwell <sfr@canb.auug.org.au>,
linux-next@vger.kernel.org, linux-kernel@vger.kernel.org,
Mike Galbraith <efault@gmx.de>,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH 1/4 tip/sched/core] sched: rename preempt_notifier to sched_notifier and always enable it
Date: Fri, 27 Nov 2009 06:46:21 +0100 [thread overview]
Message-ID: <20091127054621.GA25672@elte.hu> (raw)
In-Reply-To: <4B0F65DD.1090707@kernel.org>
* Tejun Heo <tj@kernel.org> wrote:
> Hello,
>
> 11/27/2009 01:52 PM, Ingo Molnar wrote:
> > Btw., longer term it will be faster than a mask check and a
> > default-untaken conditional: there's ongoign work to offer runtime
> > instruction patching features for tracing callbacks. There's the
> > jump patching optimization and also the immediate values patching
> > optimization.
>
> Scheduler callbacks won't benefit much from it. There will always be
> workqueues and thus conditional branch will always be necessary.
Other code will benefit from it though, such as the page fault callbacks
i already mentioned.
My position on this is rather clear: i want no new callbacks and no
changes to callbacks in the scheduler until this situation is cleaned
up. Five callback sites are _way_ too much - so if you want to add
callbacks or change them, please clean it up and improve it first.
Ingo
next prev parent reply other threads:[~2009-11-27 5:46 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-26 8:00 linux-next: manual merge of the workqueues tree with the tip tree Stephen Rothwell
2009-11-26 8:12 ` Ingo Molnar
2009-11-26 9:15 ` Tejun Heo
2009-11-26 9:26 ` Ingo Molnar
2009-11-26 9:48 ` Tejun Heo
2009-11-26 9:51 ` Ingo Molnar
2009-11-26 10:11 ` [PATCH 1/4 tip/sched/core] sched: rename preempt_notifier to sched_notifier and always enable it Tejun Heo
2009-11-26 10:29 ` Ingo Molnar
2009-11-26 10:32 ` Peter Zijlstra
2009-11-26 11:23 ` Peter Zijlstra
2009-11-26 11:56 ` Ingo Molnar
2009-11-26 12:40 ` Peter Zijlstra
2009-11-27 2:11 ` Tejun Heo
2009-11-27 4:52 ` Ingo Molnar
2009-11-27 5:38 ` Tejun Heo
2009-11-27 5:46 ` Ingo Molnar [this message]
2009-11-27 6:01 ` Tejun Heo
2009-11-27 6:13 ` Ingo Molnar
2009-11-27 6:16 ` Tejun Heo
2009-11-27 6:21 ` Ingo Molnar
2009-11-27 6:38 ` Tejun Heo
2009-11-27 7:02 ` Ingo Molnar
2009-11-26 10:44 ` Tejun Heo
2009-11-27 3:33 ` Paul Mackerras
2009-11-27 4:54 ` Ingo Molnar
2009-11-26 10:13 ` [PATCH 2/4 tip/sched/core] sched: update sched_notifier and add wakeup/sleep notifications Tejun Heo
2009-11-26 10:13 ` [PATCH 3/4 tip/sched/core] sched: refactor try_to_wake_up() and implement try_to_wake_up_local() Tejun Heo
2009-11-26 10:14 ` [PATCH 4/4 tip/sched/core] sched: implement force_cpus_allowed() Tejun Heo
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