Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965355Ab1C3Vqr (ORCPT ); Wed, 30 Mar 2011 17:46:47 -0400 Received: from mga09.intel.com ([134.134.136.24]:61722 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964845Ab1C3VHo (ORCPT ); Wed, 30 Mar 2011 17:07:44 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.63,270,1299484800"; d="scan'208";a="621237219" From: Andi Kleen References: <20110330203.501921634@firstfloor.org> In-Reply-To: <20110330203.501921634@firstfloor.org> To: jeremy.fitzhardinge@citrix.com, mingo@elte.hu, gregkh@suse.de, ak@linux.intel.com, linux-kernel@vger.kernel.org, stable@kernel.org, tim.bird@am.sony.com Subject: [PATCH] [116/275] x86/pvclock: Zero last_value on resume Message-Id: <20110330210555.CAAD03E1A05@tassilo.jf.intel.com> Date: Wed, 30 Mar 2011 14:05:55 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2576 Lines: 70 2.6.35-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Jeremy Fitzhardinge commit e7a3481c0246c8e45e79c629efd63b168e91fcda upstream. If the guest domain has been suspend/resumed or migrated, then the system clock backing the pvclock clocksource may revert to a smaller value (ie, can be non-monotonic across the migration/save-restore). Make sure we zero last_value in that case so that the domain continues to see clock updates. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen --- arch/x86/include/asm/pvclock.h | 1 + arch/x86/kernel/pvclock.c | 5 +++++ arch/x86/xen/time.c | 2 ++ 3 files changed, 8 insertions(+) Index: linux-2.6.35.y/arch/x86/include/asm/pvclock.h =================================================================== --- linux-2.6.35.y.orig/arch/x86/include/asm/pvclock.h 2011-03-29 22:51:22.108157477 -0700 +++ linux-2.6.35.y/arch/x86/include/asm/pvclock.h 2011-03-29 23:03:00.598284861 -0700 @@ -11,5 +11,6 @@ void pvclock_read_wallclock(struct pvclock_wall_clock *wall, struct pvclock_vcpu_time_info *vcpu, struct timespec *ts); +void pvclock_resume(void); #endif /* _ASM_X86_PVCLOCK_H */ Index: linux-2.6.35.y/arch/x86/kernel/pvclock.c =================================================================== --- linux-2.6.35.y.orig/arch/x86/kernel/pvclock.c 2011-03-29 22:51:22.108157477 -0700 +++ linux-2.6.35.y/arch/x86/kernel/pvclock.c 2011-03-29 23:03:00.598284861 -0700 @@ -120,6 +120,11 @@ static atomic64_t last_value = ATOMIC64_INIT(0); +void pvclock_resume(void) +{ + atomic64_set(&last_value, 0); +} + cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src) { struct pvclock_shadow_time shadow; Index: linux-2.6.35.y/arch/x86/xen/time.c =================================================================== --- linux-2.6.35.y.orig/arch/x86/xen/time.c 2011-03-29 22:51:22.109157451 -0700 +++ linux-2.6.35.y/arch/x86/xen/time.c 2011-03-29 23:03:00.629284080 -0700 @@ -425,6 +425,8 @@ { int cpu; + pvclock_resume(); + if (xen_clockevent != &xen_vcpuop_clockevent) return; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/