From patchwork Tue May 17 17:29:34 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Bader X-Patchwork-Id: 96002 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from chlorine.canonical.com (chlorine.canonical.com [91.189.94.204]) by ozlabs.org (Postfix) with ESMTP id 60248B6EDF for ; Wed, 18 May 2011 03:29:52 +1000 (EST) Received: from localhost ([127.0.0.1] helo=chlorine.canonical.com) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1QMO5R-0000L2-H0; Tue, 17 May 2011 17:29:37 +0000 Received: from adelie.canonical.com ([91.189.90.139]) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1QMO5P-0000Kx-JK for kernel-team@lists.ubuntu.com; Tue, 17 May 2011 17:29:35 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by adelie.canonical.com with esmtp (Exim 4.71 #1 (Debian)) id 1QMO5P-0002TF-A7 for ; Tue, 17 May 2011 17:29:35 +0000 Received: from p5b2e397a.dip.t-dialin.net ([91.46.57.122] helo=canonical.com) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1QMO5P-0008Ep-5N for kernel-team@lists.ubuntu.com; Tue, 17 May 2011 17:29:35 +0000 From: Stefan Bader To: kernel-team@lists.ubuntu.com Subject: [Lucid-ec2] SRU: XEN: Do not force sched_clock_stable Date: Tue, 17 May 2011 19:29:34 +0200 Message-Id: <1305653374-2163-1-git-send-email-stefan.bader@canonical.com> X-Mailer: git-send-email 1.7.0.4 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: kernel-team-bounces@lists.ubuntu.com Errors-To: kernel-team-bounces@lists.ubuntu.com SRU Justification Impact: When applying the Xen patchset one endif seems to have gone to the wrong place. So instead of not setting sched_clock_stable it is done all the time. Fix: Move endif so the whole code segment is covered. Testcase: Can cause various effects and depends on CPU (see below). Incorrect CPU time but likely also causing the unexplainable process gets stuck or clone/fork issues. Acked-by: Leann Ogasawara Acked-by: John Johansen --- From 5f1bda076198807960d023c4d1551485c8d77ef5 Mon Sep 17 00:00:00 2001 From: Stefan Bader Date: Tue, 17 May 2011 19:16:30 +0200 Subject: [PATCH] UBUNTU: SAUCE: XEN: Do not force sched_clock_stable BugLink: http://bugs.launchpad.net/bugs/727459 This is part of the changes that have been found while syncing up the patchsets. Apparently when applying the endif went into the wrong place and causes the clock to be assumed always stable. Which causes problems on certain CPUs (probably the fork/clone hang as well as processes getting stuck for a longer time). Signed-off-by: Stefan Bader --- arch/x86/kernel/cpu/intel.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 0aad121..f582b21 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -97,8 +97,8 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c) set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC); #ifndef CONFIG_XEN if (!check_tsc_unstable()) -#endif sched_clock_stable = 1; +#endif } /*