From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EC13BC282C2 for ; Wed, 23 Jan 2019 11:56:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B96CE21841 for ; Wed, 23 Jan 2019 11:56:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726168AbfAWL4m (ORCPT ); Wed, 23 Jan 2019 06:56:42 -0500 Received: from mx2.suse.de ([195.135.220.15]:34038 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726228AbfAWL4l (ORCPT ); Wed, 23 Jan 2019 06:56:41 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 941A4B0EC; Wed, 23 Jan 2019 11:56:40 +0000 (UTC) From: Juergen Gross To: stable@vger.kernel.org Cc: Juergen Gross , Pavel Tatashin , Thomas Gleixner Subject: [Patch-for-stable-4.14 5/6] x86/xen/time: Output xen sched_clock time from 0 Date: Wed, 23 Jan 2019 12:56:35 +0100 Message-Id: <20190123115636.19710-6-jgross@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20190123115636.19710-1-jgross@suse.com> References: <20190123115636.19710-1-jgross@suse.com> Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org It is expected for sched_clock() to output data from 0, when system boots. Add an offset xen_sched_clock_offset (similarly how it is done in other hypervisors i.e. kvm_sched_clock_offset) to count sched_clock() from 0, when time is first initialized. Signed-off-by: Pavel Tatashin Signed-off-by: Thomas Gleixner Signed-off-by: Juergen Gross --- This is upstream commit 38669ba205d178d2d38bfd194a196d65a44d5af2. Needed for upstream commit 867cefb4cb1012f42cada1c7d1f35ac8dd276071. --- arch/x86/xen/time.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index efa81e736f43..8c0b2beb3f46 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -31,6 +31,8 @@ /* Xen may fire a timer up to this many ns early */ #define TIMER_SLOP 100000 +static u64 xen_sched_clock_offset __read_mostly; + /* Get the TSC speed from Xen */ static unsigned long xen_tsc_khz(void) { @@ -57,6 +59,11 @@ static u64 xen_clocksource_get_cycles(struct clocksource *cs) return xen_clocksource_read(); } +static u64 xen_sched_clock(void) +{ + return xen_clocksource_read() - xen_sched_clock_offset; +} + static void xen_read_wallclock(struct timespec *ts) { struct shared_info *s = HYPERVISOR_shared_info; @@ -367,7 +374,7 @@ void xen_timer_resume(void) } static const struct pv_time_ops xen_time_ops __initconst = { - .sched_clock = xen_clocksource_read, + .sched_clock = xen_sched_clock, .steal_clock = xen_steal_clock, }; @@ -505,6 +512,7 @@ static void __init xen_time_init(void) void __ref xen_init_time_ops(void) { + xen_sched_clock_offset = xen_clocksource_read(); pv_time_ops = xen_time_ops; x86_init.timers.timer_init = xen_time_init; @@ -547,6 +555,7 @@ void __init xen_hvm_init_time_ops(void) return; } + xen_sched_clock_offset = xen_clocksource_read(); pv_time_ops = xen_time_ops; x86_init.timers.setup_percpu_clockev = xen_time_init; x86_cpuinit.setup_percpu_clockev = xen_hvm_setup_cpu_clockevents; -- 2.16.4