From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755421AbaD1Bcz (ORCPT ); Sun, 27 Apr 2014 21:32:55 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:42874 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752503AbaD1B3V (ORCPT ); Sun, 27 Apr 2014 21:29:21 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Haiyang Zhang" , "K. Y. Srinivasan" , "H. Peter Anvin" , "Jason Wang" Date: Mon, 28 Apr 2014 02:11:22 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 60/94] x86, hyperv: Bypass the timer_irq_works() check In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.58-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jason Wang commit ca3ba2a2f4a49a308e7d78c784d51b2332064f15 upstream. This patch bypass the timer_irq_works() check for hyperv guest since: - It was guaranteed to work. - timer_irq_works() may fail sometime due to the lpj calibration were inaccurate in a hyperv guest or a buggy host. In the future, we should get the tsc frequency from hypervisor and use preset lpj instead. [ hpa: I would prefer to not defer things to "the future" in the future... ] Cc: K. Y. Srinivasan Cc: Haiyang Zhang Acked-by: K. Y. Srinivasan Signed-off-by: Jason Wang Link: http://lkml.kernel.org/r/1393558229-14755-1-git-send-email-jasowang@redhat.com Signed-off-by: H. Peter Anvin [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- arch/x86/kernel/cpu/mshyperv.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -18,6 +18,7 @@ #include #include #include +#include struct ms_hyperv_info ms_hyperv; EXPORT_SYMBOL_GPL(ms_hyperv); @@ -70,6 +71,11 @@ static void __init ms_hyperv_init_platfo if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE) clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100); + +#ifdef CONFIG_X86_IO_APIC + no_timer_check = 1; +#endif + } const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {