From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751854Ab1LBFtG (ORCPT ); Fri, 2 Dec 2011 00:49:06 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:46134 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751176Ab1LBFtE (ORCPT ); Fri, 2 Dec 2011 00:49:04 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Fri, 2 Dec 2011 14:47:48 +0900 From: KAMEZAWA Hiroyuki To: Mike Galbraith Cc: Jason Baron , "linux-kernel@vger.kernel.org" , Peter Zijlstra , Jeremy Fitzhardinge , rostedt@goodmis.org Subject: Re: [PATCH] jump_label: jump_label for boot options. Message-Id: <20111202144748.7fa32a57.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <1322804045.4755.13.camel@marge.simson.net> References: <20111201115353.563f79fc.kamezawa.hiroyu@jp.fujitsu.com> <20111201154036.GA2443@redhat.com> <20111202092837.58e11827.kamezawa.hiroyu@jp.fujitsu.com> <1322804045.4755.13.camel@marge.simson.net> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 3.1.1 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 02 Dec 2011 06:34:05 +0100 Mike Galbraith wrote: > On Fri, 2011-12-02 at 09:28 +0900, KAMEZAWA Hiroyuki wrote: > > On Thu, 1 Dec 2011 10:40:36 -0500 > > Jason Baron wrote: > > > > > On Thu, Dec 01, 2011 at 11:53:53AM +0900, KAMEZAWA Hiroyuki wrote: > > > > I tried to use jump_label for handling memcg's boot options which sets > > > > global variable true/false and never changes after boot. And found jump_table > > > > is larger than expected. This patch is a trial to allow to place jump_table > > > > in .init section. How do you think ? > > > > > > > > > > Remeber too, that 'static_branch()' is inherently biased. That is, the > > > 'false' path is assumed to be the the most likely path. Thus, the 'true' > > > path is move out-of-line. Thus, if the 'true' branch is potentially > > > used all the time, we would want to make sure that the savings of not > > > having to check a variable is still worth it. I should probably rename > > > static_branch() -> 'static_branch_default_false()' to make that clear. > > > > > Thank you for pointing out. > > > > My assumption is that it's disabled at boot by few people because sane > > people will not config memcg if they don't want. Most of distro users > > will not turn off it... > > I think that's a bad assumption. I see a lot of cgroup_disable=memory > command lines, and _always_ add it to grub when installing "everything > plus the kitchen sink" distro kernels on my boxen. > Ok, I stop this work. Thanks, -Kame