From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752654Ab0JPCmg (ORCPT ); Fri, 15 Oct 2010 22:42:36 -0400 Received: from smtp.srv.ualberta.ca ([129.128.5.19]:55443 "EHLO mail7.srv.ualberta.ca" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752355Ab0JPCmf (ORCPT ); Fri, 15 Oct 2010 22:42:35 -0400 Date: Fri, 15 Oct 2010 20:42:35 -0600 (Mountain Daylight Time) From: Marc Aurele La France Reply-To: linux-kernel@vger.kernel.org, tsi@ualberta.ca To: linux-kernel@vger.kernel.org, Len Brown Subject: Re: x86_64 2.6.35.* kernels and Intel Xeon X5550 In-Reply-To: Message-ID: References: User-Agent: Alpine 1.10 (WNT 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 7 Oct 2010, Marc Aurele La France wrote: > I administer a cluster composed of a mixture of various Opteron models and > Intel Xeon X5550's. The 2.6.34.*, and prior, kernels run fine on all of > them. The 2.6.35 series also runs fine on the Opterons, but not on the > Xeon's. All of these are CONFIG_GENERIC_CPU kernels. > On the Xeon's, 2.6.35 hangs early on, upon the first test of trace events > (in kernel/trace/trace_events.c:event_trace_self_tests()). When disabling > all tracing, debugging, etc., it still hangs but slightly later. The > megaraid_sas module is loaded, detects the adapter, but never gets around to > registering it with the SCSI layer. > Core2-specific kernels also hang the same way, as do UP kernels. I've tried > backing out certain commits that seemed likely candidates, but have yet to > stumble upon the one (or more) that is causing this. > Does anyone have any ideas? This is due to "CONFIG_INTEL_IDLE=y". "m" or "n", the hang doesn't occur. Of the kernels I've tested, INTEL_IDLE first appears in 2.6.34-git15. So, technically, this is not a regression against 2.6.34. This does, however, amount to a vote of non-confidence against intel_idle.c. Marc. +----------------------------------+----------------------------------+ | Marc Aurele La France | work: 1-780-492-9310 | | Academic Information and | fax: 1-780-492-1729 | | Communications Technologies | email: tsi@ualberta.ca | | 352 General Services Building +----------------------------------+ | University of Alberta | | | Edmonton, Alberta | Standard disclaimers apply | | T6G 2H1 | | | CANADA | | +----------------------------------+----------------------------------+