From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: linux-next: build failure after merge of the tip tree Date: Sat, 18 Jan 2014 11:14:57 -0800 Message-ID: <52DAD2B1.2050401@zytor.com> References: <20140116145829.5e4fcab103b1c5c77501ee77@canb.auug.org.au> <20140116121955.GQ31570@twins.programming.kicks-ass.net> <20140117074628.88698f59939c9002b7c12968@canb.auug.org.au> <20140116222536.GX30183@twins.programming.kicks-ass.net> <20140117093426.ee8e3d1bb2e95c9f67ec625b@canb.auug.org.au> <52D8625C.1000902@zytor.com> <20140117144518.231fa4bccb16a8d7edd36662@canb.auug.org.au> <1390038366.5676.10.camel@marge.simpson.net> <20140118124451.GA30183@twins.programming.kicks-ass.net> <1390058494.5439.3.camel@marge.simpson.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from terminus.zytor.com ([198.137.202.10]:46488 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751347AbaARTQ2 (ORCPT ); Sat, 18 Jan 2014 14:16:28 -0500 In-Reply-To: <1390058494.5439.3.camel@marge.simpson.net> Sender: linux-next-owner@vger.kernel.org List-ID: To: Mike Galbraith , Peter Zijlstra Cc: Stephen Rothwell , Thomas Gleixner , Ingo Molnar , Len Brown , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org Archived-At: List-Archive: List-Post: On 01/18/2014 07:21 AM, Mike Galbraith wrote: > On Sat, 2014-01-18 at 13:44 +0100, Peter Zijlstra wrote: >> On Sat, Jan 18, 2014 at 10:46:06AM +0100, Mike Galbraith wrote: >>> >>> I hope it doesn't look quite like that, next-20140117 is -ENOBOOT on >>> Q6600 box. See below for an alternative. >> >> Urgh, I see, we call the idle arch_cpu_idle() callback with irqs >> disabled. >> >> Could something like this work? >> >> local_irq_enable(); >> mwait_idle_with_hints(0,0); >> >> The interrupt enable window is slightly larger, but I'm not immediately >> seeing a problem with that. > > Yup, works just fine. Less is more. > > Nice to see a _progression_ in the pipe too btw. > This means an interrupt window is open and we can take an interrupt between checking need_resched and the MWAIT, which couldn't happen with __sti_mwait(). Are we sure that is actually safe? -hpa