Received: by 2002:ac0:a581:0:0:0:0:0 with SMTP id m1-v6csp65506imm; Tue, 3 Jul 2018 14:02:57 -0700 (PDT) X-Google-Smtp-Source: ADUXVKLZs8BLe1EQTqX9+b81j1q+UKBE4mvGTP5lM/FTGR1r8Vd0jZlV+eymrvMy8gc8T6gybJOq X-Received: by 2002:a65:5144:: with SMTP id g4-v6mr26910374pgq.21.1530651777777; Tue, 03 Jul 2018 14:02:57 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1530651777; cv=none; d=google.com; s=arc-20160816; b=jVq4+cXRi50xmTYmIBGaaRYZvy89UQUM6xWrBcLT1gy0Jsy6z2RVsJp34j3Cz5+6rS SNwcMQj27KepKx24RiWv2WtPQEKL3DoD+uks6pEBsTswovjPnJWZxDq1oYQqcIxMee8z weL3qSOy8Jn7a5nwpBqXCwONTxEUQRTHLP+EJv0CWaZF9pjCYWx0y1ehzAFzqCCgi1JD sQq0nyYtXdSrjT19VltrrBqh6ag28mooTZgnu68XCoIXLQKk3UkTJ1zwfpfF9tA89niG r+VknYm0bqyrb43l81XICRM9c1QD/YcM+4uhSeO8KsSZwJdEZsylwKEyjq46vClo0BX4 +/gA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:mime-version:user-agent:references :message-id:in-reply-to:subject:cc:to:from:date :arc-authentication-results; bh=+1/EBdE1/qKGAI79g3aOgXvDanmaCrseK1cb+deFexc=; b=Xd2hcKmkTcn+kMW3zL9zAM0rj9v6OdWhveHhif7qSY4e3dpO3Nl3Mtj8au6v5SS4Og J95JYUgjn6K29ffnUAuJePKlwjlTmWg5RWo7e4LEjMbTeOswXEUWfDl2YuLdA1LEmDjw aEaXpi3erpOfaU5hYHFP/crtmm9xOBGBljxiyIPfmlSkjJReudJT+ZSiCcEE01BsdbRL 4j8cInzeSWE+5P/mHSDac9KL40c+g0o+JCv/64it9QDzzqDAMCn9iTWzV6KHg1yBDVBm 6g0TXpQR5U7pYiY7SVjlUUJOXkT0IMyv9oKCxZvCnvK4QXIs2tOZLUZi28k4EUVLvHnm zshg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id w11-v6si1697006pgt.596.2018.07.03.14.02.37; Tue, 03 Jul 2018 14:02:57 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753366AbeGCVA3 (ORCPT + 99 others); Tue, 3 Jul 2018 17:00:29 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:45493 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752862AbeGCVA1 (ORCPT ); Tue, 3 Jul 2018 17:00:27 -0400 Received: from p4fea482e.dip0.t-ipconnect.de ([79.234.72.46] helo=nanos) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1faSOa-0002iO-3a; Tue, 03 Jul 2018 22:59:32 +0200 Date: Tue, 3 Jul 2018 22:59:31 +0200 (CEST) From: Thomas Gleixner To: Pavel Tatashin cc: Steven Sistare , Daniel Jordan , linux@armlinux.org.uk, Martin Schwidefsky , Heiko Carstens , John Stultz , sboyd@codeaurora.org, x86@kernel.org, LKML , mingo@redhat.com, "H. Peter Anvin" , douly.fnst@cn.fujitsu.com, Peter Zijlstra , Prarit Bhargava , feng.tang@intel.com, Petr Mladek , gnomes@lxorguk.ukuu.org.uk, linux-s390@vger.kernel.org, andriy.shevchenko@linux.intel.com, boris.ostrovsky@oracle.com, pbonzini@redhat.com Subject: Re: [PATCH v12 09/11] x86/tsc: prepare for early sched_clock In-Reply-To: <20180629085752.zkbxlwc2rzlm63lk@xakep.localdomain> Message-ID: References: <20180629085752.zkbxlwc2rzlm63lk@xakep.localdomain> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 29 Jun 2018, Pavel Tatashin wrote: > On 18-06-29 09:30:10, Thomas Gleixner wrote: > For now, in my series, I would like check in tsc_early_init() if we are > running xen, and set tsc_khz to 0 if so. Later in tsc_init() we will get > a proper calibration. The question is how to make this check least > intrusive. By not having it at all. Talk to the XEN folks (IIRC there are a few coworkers of you involved with XEN). Thanks, tglx