public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Andi Kleen <andi@firstfloor.org>
To: paulmck@linux.vnet.ibm.com
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu,
	laijs@cn.fujitsu.com, dipankar@in.ibm.com,
	akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca,
	josh@joshtriplett.org, dvhltc@us.ibm.com, niv@us.ibm.com,
	tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org,
	Valdis.Kletnieks@vt.edu, dhowells@redhat.com
Subject: Re: [PATCH RFC tip/core/rcu] accelerate grace period if last non-dynticked CPU
Date: Tue, 26 Jan 2010 22:30:57 +0100	[thread overview]
Message-ID: <873a1sft9q.fsf@basil.nowhere.org> (raw)
In-Reply-To: <20100125034816.GA14043@linux.vnet.ibm.com> (Paul E. McKenney's message of "Sun, 24 Jan 2010 19:48:16 -0800")

"Paul E. McKenney" <paulmck@linux.vnet.ibm.com> writes:

Kind of offtopic to the original patch, but I couldn't 
resist...

> +config RCU_FAST_NO_HZ
> +	bool "Accelerate last non-dyntick-idle CPU's grace periods"
> +	depends on TREE_RCU && NO_HZ && SMP

Having such a thing as a config option doesn't really make 
any sense to me. Who would want to recompile their kernel
to enable/disable this? If anything it should be runtime, or better
just unconditionally on.

In general RCU could probably reduce its number of "weird"
Kconfig options.

While I think I have a better understanding of RCU than a lot
of normal users I often have no clue what to set there when
building a kernel.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only.

  parent reply	other threads:[~2010-01-26 21:31 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-25  3:48 [PATCH RFC tip/core/rcu] accelerate grace period if last non-dynticked CPU Paul E. McKenney
2010-01-25 12:28 ` Lai Jiangshan
2010-01-25 12:35   ` Peter Zijlstra
2010-01-25 15:08   ` Steven Rostedt
2010-01-27  5:17   ` Paul E. McKenney
2010-01-25 15:12 ` Steven Rostedt
2010-01-27 14:11   ` Paul E. McKenney
2010-01-27 14:52     ` Steven Rostedt
2010-01-26 21:30 ` Andi Kleen [this message]
2010-01-26 23:55   ` Mathieu Desnoyers
2010-01-27  5:21     ` Paul E. McKenney
2010-01-27  5:20   ` Paul E. McKenney
2010-01-27  9:43     ` Andi Kleen
2010-01-27  9:50       ` Peter Zijlstra
2010-01-27 10:00         ` Andi Kleen
2010-01-27 10:04         ` Paul E. McKenney
2010-01-27 11:39           ` Nick Piggin
2010-01-27 11:59             ` Paul E. McKenney
2010-01-27 10:01       ` Paul E. McKenney
2010-01-27 10:13         ` Andi Kleen
2010-01-27 11:44           ` Paul E. McKenney
2010-01-27 12:11             ` Andi Kleen
2010-01-27 13:23               ` Paul E. McKenney

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=873a1sft9q.fsf@basil.nowhere.org \
    --to=andi@firstfloor.org \
    --cc=Valdis.Kletnieks@vt.edu \
    --cc=akpm@linux-foundation.org \
    --cc=dhowells@redhat.com \
    --cc=dipankar@in.ibm.com \
    --cc=dvhltc@us.ibm.com \
    --cc=josh@joshtriplett.org \
    --cc=laijs@cn.fujitsu.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mathieu.desnoyers@polymtl.ca \
    --cc=mingo@elte.hu \
    --cc=niv@us.ibm.com \
    --cc=paulmck@linux.vnet.ibm.com \
    --cc=peterz@infradead.org \
    --cc=rostedt@goodmis.org \
    --cc=tglx@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox