From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <479F85F9.3040104@sgi.com> Date: Tue, 29 Jan 2008 12:00:57 -0800 From: Mike Travis MIME-Version: 1.0 Subject: Re: [PATCH 0/3] percpu: Optimize percpu accesses References: <20080123044924.508382000@sgi.com> <20080124224613.GA24855@elte.hu> In-Reply-To: <20080124224613.GA24855@elte.hu> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Ingo Molnar Cc: Andrew Morton , Andi Kleen , Christoph Lameter , jeremy@goop.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: Ingo Molnar wrote: ... > > tried it on x86.git and 1/3 did not build and 2/3 causes a boot hang > with the attached .config. > > Ingo > I've tracked down the failure to an early printk that when CONFIG_PRINTK_TIME is enabled, any early printks cause cpu_clock to be called, which accesses cpu_rq which is defined as: 595 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) Since the zero-based patch is changing the offset from one based on __per_cpu_start to zero, it's causing the function to access a different area. I'm working on a fix now. Thanks, Mike -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org