From patchwork Fri Aug 21 22:29:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anchal Agarwal X-Patchwork-Id: 11730729 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 127BC913 for ; Fri, 21 Aug 2020 22:31:04 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E2C5C20738 for ; Fri, 21 Aug 2020 22:31:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="YzjobU6B" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E2C5C20738 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=amazon.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1k9FYC-0005ZW-EU; Fri, 21 Aug 2020 22:30:20 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1k9FYA-0005ZM-RZ for xen-devel@lists.xenproject.org; Fri, 21 Aug 2020 22:30:18 +0000 X-Inumbo-ID: 2ecafaa9-ea2a-4e85-a078-770b6872555c Received: from smtp-fw-4101.amazon.com (unknown [72.21.198.25]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 2ecafaa9-ea2a-4e85-a078-770b6872555c; Fri, 21 Aug 2020 22:30:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1598049019; x=1629585019; h=date:from:to:subject:message-id:references:mime-version: in-reply-to; bh=YPGbk1ro99+2byQqY7wPsPaRaSmgzuUay7e4tUoB1AM=; b=YzjobU6BS6IEvpIpm3kje97G0GOU5Te5Jvm6te0kuOORu0B+fPfD6X+H ajL61SJpP4mxYq+GrYd3XDMeUi8bYT5mapYahLiniWNpQB5+uEHtf6BVc sGvbXJvzSGk0fGdrADrg5w4Sw0iLov4YCwkEBshUfvrMMGfmeNLXsRwbo E=; X-IronPort-AV: E=Sophos;i="5.76,338,1592870400"; d="scan'208";a="49403800" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-1d-5dd976cd.us-east-1.amazon.com) ([10.43.8.6]) by smtp-border-fw-out-4101.iad4.amazon.com with ESMTP; 21 Aug 2020 22:30:19 +0000 Received: from EX13MTAUWC001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan2.iad.amazon.com [10.40.159.162]) by email-inbound-relay-1d-5dd976cd.us-east-1.amazon.com (Postfix) with ESMTPS id 06E32A2486; Fri, 21 Aug 2020 22:30:11 +0000 (UTC) Received: from EX13D05UWC003.ant.amazon.com (10.43.162.226) by EX13MTAUWC001.ant.amazon.com (10.43.162.135) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Fri, 21 Aug 2020 22:29:55 +0000 Received: from EX13MTAUWC001.ant.amazon.com (10.43.162.135) by EX13D05UWC003.ant.amazon.com (10.43.162.226) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Fri, 21 Aug 2020 22:29:55 +0000 Received: from dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (172.22.96.68) by mail-relay.amazon.com (10.43.162.232) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Fri, 21 Aug 2020 22:29:54 +0000 Received: by dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (Postfix, from userid 4335130) id 3480C40362; Fri, 21 Aug 2020 22:29:55 +0000 (UTC) Date: Fri, 21 Aug 2020 22:29:55 +0000 From: Anchal Agarwal To: , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v3 08/11] x86/xen: save and restore steal clock during PM hibernation Message-ID: <5c3be5c7519b1f63a51b08abc388c33bd6f66661.1598042152.git.anchalag@amazon.com> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Precedence: Bulk X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Save/restore steal times in syscore suspend/resume during PM hibernation. Commit '5e25f5db6abb9: ("xen/time: do not decrease steal time after live migration on xen")' fixes xen guest steal time handling during migration. A similar issue is seen during PM hibernation. Currently, steal time accounting code in scheduler expects steal clock callback to provide monotonically increasing value. If the accounting code receives a smaller value than previous one, it uses a negative value to calculate steal time and results in incorrectly updated idle and steal time accounting. This breaks userspace tools which read /proc/stat. top - 08:05:35 up 2:12, 3 users, load average: 0.00, 0.07, 0.23 Tasks: 80 total, 1 running, 79 sleeping, 0 stopped, 0 zombie Cpu(s): 0.0%us, 0.0%sy, 0.0%ni,30100.0%id, 0.0%wa, 0.0%hi, 0.0%si,-1253874204672.0%st This can actually happen when a Xen PVHVM guest gets restored from hibernation, because such a restored guest is just a fresh domain from Xen perspective and the time information in runstate info starts over from scratch. Changelog: v1->v2: Removed patches that introduced new function calls for saving/restoring sched clock offset and using existing ones that are used during LM Signed-off-by: Anchal Agarwal --- arch/x86/xen/suspend.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c index 550aa0fc9465..b12db6966af6 100644 --- a/arch/x86/xen/suspend.c +++ b/arch/x86/xen/suspend.c @@ -99,6 +99,7 @@ static int xen_syscore_suspend(void) gnttab_suspend(); + xen_manage_runstate_time(-1); xrfp.domid = DOMID_SELF; xrfp.gpfn = __pa(HYPERVISOR_shared_info) >> PAGE_SHIFT; @@ -119,7 +120,7 @@ static void xen_syscore_resume(void) xen_hvm_map_shared_info(); pvclock_resume(); - + xen_manage_runstate_time(0); gnttab_resume(); }