From owner-freebsd-arch@freebsd.org Fri Jun 3 14:28:33 2016 Return-Path: Delivered-To: freebsd-arch@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 502F7B6856E for ; Fri, 3 Jun 2016 14:28:33 +0000 (UTC) (envelope-from sobomax@sippysoft.com) Received: from mail-oi0-x22f.google.com (mail-oi0-x22f.google.com [IPv6:2607:f8b0:4003:c06::22f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 146731AB0 for ; Fri, 3 Jun 2016 14:28:33 +0000 (UTC) (envelope-from sobomax@sippysoft.com) Received: by mail-oi0-x22f.google.com with SMTP id j1so128993982oih.3 for ; Fri, 03 Jun 2016 07:28:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sippysoft-com.20150623.gappssmtp.com; s=20150623; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=/R1r4y9qtKUG1dHzy0HWyVDbah0Oa/cO79CxNqLFass=; b=x279AAiC/I/Tnt/vlSykudYqoId3KDJnLN5N64dcBjybxaYicygHPAUQKlfU+XhtSp aYhkB/ZbVO8Ipc+u4kIANOl1fMs3QZH0MrGYpVzL5runJ5AF/uC7UD98TDg8+L95CwAA YlF+4Lru9l1OSOEmCXYgdE/MwWK3O5IQJ3weBYI3dKpwEiz1Kfvf+guniqyEAnBsrgs5 x+unrPYfDeNk4BQ+RQf+yYb9y1fB2PaAkRxmjgZjHxvDXZBn3qi0oVH+uhXbeYoWhjaz BgNiW/60SjOysNd8EljJEqG6myMfTxgiFcxYz2nkLXEQlwYmfVySzUspF9B+m/zc625O ga2w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=/R1r4y9qtKUG1dHzy0HWyVDbah0Oa/cO79CxNqLFass=; b=V+IXA+wR5UysSgXv73En/9eYtKaAZZJIyWrqc8DIQx4mgfft9iPd9Pn/AB5tm+cugT sIptAl+JjLh793g1KN3Yi6080yms66vVf6tfl2ObZy8Zzbsgr+fcHkuQdxN7NhJi7a4m YyqkqHzoBeMAP16pe0gdNqqDFPJeMF9oad2mq4Ft5WtOib58jyrN7xzBK+1QMW0GE90b 0cZ9RgpB13+KMJCQnJgwybl5gtSm88pbSqyyBj5haBImiBGVf1k62EOyMCuS9uuJ9J+X 25+lam/1DBJDZvd5263Nr1EA68gMqGTlI/046Qg0Xerh16OxoUU6FTqO6B8BxCLbs8Mq o6DQ== X-Gm-Message-State: ALyK8tLshLF6Ov0WJA1QmgJ2wswOhQ4zFokG69dZbzmmPfQqtg3l1rd4B1aMW+s2ff8QDCbxKrRMkss19cCsg/j9 X-Received: by 10.157.31.78 with SMTP id x14mr2143800otx.15.1464964112288; Fri, 03 Jun 2016 07:28:32 -0700 (PDT) MIME-Version: 1.0 Sender: sobomax@sippysoft.com Received: by 10.157.56.70 with HTTP; Fri, 3 Jun 2016 07:28:31 -0700 (PDT) In-Reply-To: References: From: Maxim Sobolev Date: Fri, 3 Jun 2016 07:28:31 -0700 X-Google-Sender-Auth: _Ht2eSLKxKB2HEHmY-rA1U04kUI Message-ID: Subject: Re: CLOCK_MONOTONIC / CLOCK_UPTIME is not really monotonic between threads To: Adrian Chadd Cc: FreeBSD Current , freebsd-threads@freebsd.org, FreeBSD Questions , "freebsd-arch@freebsd.org" Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.22 X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Jun 2016 14:28:33 -0000 a. multiple cores. b. makes no difference c. yes, I believe so kern.timecounter.tsc_shift: 1 kern.timecounter.smp_tsc_adjust: 0 kern.timecounter.smp_tsc: 1 kern.timecounter.invariant_tsc: 1 machdep.tsc_freq: 2658118740 machdep.disable_tsc_calibration: 0 machdep.disable_tsc: 0 d. no, single socket Intel Q6700. I've also seen this problem on core i7-4770 running virtualbox 5.x. I have a hints that this also happens on our bigger production boxes, but I have no specifics yet. On Thu, Jun 2, 2016 at 10:05 PM, Adrian Chadd wrote: > [snip] > > a) is it on one core, or multiple cores? > b) CLOCK_MONOTONIC_FAST? > c) is it on a system that /has/ invariant-TSC ? > d) is this a multi-socket system? > > > > -adrian > >