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=-2.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, T_DKIMWL_WL_HIGH,UNPARSEABLE_RELAY,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 08E5BC43A1D for ; Thu, 12 Jul 2018 00:08:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B822B20BEC for ; Thu, 12 Jul 2018 00:08:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="Dkkf07km" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B822B20BEC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388798AbeGLAOx (ORCPT ); Wed, 11 Jul 2018 20:14:53 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:44540 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390903AbeGLANI (ORCPT ); Wed, 11 Jul 2018 20:13:08 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w6C04tGL148215; Thu, 12 Jul 2018 00:04:55 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : subject : date : message-id : in-reply-to : references; s=corp-2018-07-02; bh=Bm1hL3z8KtKQZK7Ksi8zPH4LHPDtf/936zlUb2rvrFk=; b=Dkkf07kmjeaefdG3PVbojyMNbGEiVvLRUZ+RelLiBan3k1C4P7oSt6waxVUt4VcaQF0t lB80COj5GWldGde/EsGeCdtkQbu+1pfJPlyCUk7/eeX+qtmohupWycPCvkv+oOfnLC0b LMdbTjVZMXPetzdK6vnKoBZUtjZxs0jOz+UxCEqfL5u6Kf9cWNHZ1G2uXUsII4bT6Exu Y5K8C7LCEBiNFymv8myvduECu/7n2PhsEIYaYU6LQYo6xUDI1WuxotAwsafNRqNz15dJ XltVp334D8E7/ClCIBfCIqSCigsmDlAx/cdJgCKL595R3Ih2XFFQQnGDBPcqVjR3Kq/r rQ== Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by userp2130.oracle.com with ESMTP id 2k2p768ae8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 12 Jul 2018 00:04:55 +0000 Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w6C04sAl000754 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 12 Jul 2018 00:04:54 GMT Received: from abhmp0003.oracle.com (abhmp0003.oracle.com [141.146.116.9]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id w6C04r1G004663; Thu, 12 Jul 2018 00:04:53 GMT Received: from localhost.localdomain (/73.69.118.222) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 11 Jul 2018 17:04:53 -0700 From: Pavel Tatashin To: steven.sistare@oracle.com, daniel.m.jordan@oracle.com, linux@armlinux.org.uk, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, john.stultz@linaro.org, sboyd@codeaurora.org, x86@kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, hpa@zytor.com, douly.fnst@cn.fujitsu.com, peterz@infradead.org, prarit@redhat.com, feng.tang@intel.com, pmladek@suse.com, gnomes@lxorguk.ukuu.org.uk, linux-s390@vger.kernel.org, pasha.tatashin@oracle.com, boris.ostrovsky@oracle.com, jgross@suse.com Subject: [PATCH v13 15/18] x86/tsc: use tsc early Date: Wed, 11 Jul 2018 20:04:16 -0400 Message-Id: <20180712000419.5165-16-pasha.tatashin@oracle.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180712000419.5165-1-pasha.tatashin@oracle.com> References: <20180712000419.5165-1-pasha.tatashin@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8951 signatures=668706 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=949 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1806210000 definitions=main-1807110252 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org get timestamps and high resultion clock available to us as early as possible. native_sched_clock() outputs time based either on tsc after tsc_init() is called later in boot, or using jiffies when clock interrupts are enabled, which is also happens later in boot. On the other hand, tsc frequency is known from as early as when tsc_early_init() is called. Use the early tsc calibration to output timestamps early. Signed-off-by: Pavel Tatashin --- arch/x86/kernel/tsc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 0b1abe7fdd8e..39ff2881f622 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -1408,6 +1408,7 @@ void __init tsc_early_init(void) /* Sanitize TSC ADJUST before cyc2ns gets initialized */ tsc_store_and_check_tsc_adjust(true); cyc2ns_init_boot_cpu(); + static_branch_enable(&__use_tsc); } void __init tsc_init(void) -- 2.18.0