From owner-freebsd-current@freebsd.org Mon Sep 9 21:17:00 2019 Return-Path: Delivered-To: freebsd-current@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id CFD29E19A5 for ; Mon, 9 Sep 2019 21:17:00 +0000 (UTC) (envelope-from ian@freebsd.org) Received: from outbound3d.ore.mailhop.org (outbound3d.ore.mailhop.org [54.186.57.195]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 46S1FS33sJz4fxD for ; Mon, 9 Sep 2019 21:17:00 +0000 (UTC) (envelope-from ian@freebsd.org) ARC-Seal: i=1; a=rsa-sha256; t=1568063818; cv=none; d=outbound.mailhop.org; s=arc-outbound20181012; b=AvOJBCLAJm/BOLWBjnzW9nIxnLi6q5W1nY5M3K4flQmsDdoESPci2bzqKcXrOZ8Tm/WkRMoQQf5KZ rETrMwP4x3kj5g1oO8RPoQGSDYQFvUpT06tWqrkX02BwdHcmLJCv6/YHHZxaWNJVzQMENNGKspFilp GqZjhoaNB4KmaTac1wTfYpp+xn6hhJfu7XgqVqixq4VmHr+1sczc/7Qu2i+ELWJ39V1oQPiNIC4AxI ml0kPhZU/vdIAy/HiCq0fM7TVW21XsA11FQeQKZwDk8uSAbgcjvjspyZ6qAFGZKknVtiqq8WceyIRL g/gYGCcCa9jy6AimlbNlIMzkQd528PA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=outbound.mailhop.org; s=arc-outbound20181012; h=content-transfer-encoding:mime-version:content-type:references:in-reply-to: date:cc:to:from:subject:message-id:dkim-signature:from; bh=K8JlJv5D8SqwpQDVvyqkrrgFFVQ7wa3mT+zv7Vk5bJA=; b=qvp/zU3IOmsNoHmKWO2o8njhO0tyYRGMo+Sn7dSMjuwNQ/4x2giW++gGC7g2jjD47RYxVUifI5Gej K0jMvQk1lfyi5VNItepTA5pUWQMCSlbQVF2ianGeQ2voLgzvSSpc1rF/NzKQus4vpsRTkrM5p8mUq6 FGOulReOhupzWekwXN1/XJm9ZW7ivfRaOkywHC4IK9VpV8kq155GocvRp8XA/rY95dBa1wrb/Qcr2z tQqzkrOPhaa9YMQqizLsr9hWd2qC3DlnxLAC2py3NCVDKPO8qMz/wcKIQFc7J0KDQwaz4pWV+CSgAJ +bxaDFqdwPCwdKEXPEOD783ArsuWCog== ARC-Authentication-Results: i=1; outbound3.ore.mailhop.org; spf=softfail smtp.mailfrom=freebsd.org smtp.remote-ip=67.177.211.60; dmarc=none header.from=freebsd.org; arc=none header.oldest-pass=0; DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=outbound.mailhop.org; s=dkim-high; h=content-transfer-encoding:mime-version:content-type:references:in-reply-to: date:cc:to:from:subject:message-id:from; bh=K8JlJv5D8SqwpQDVvyqkrrgFFVQ7wa3mT+zv7Vk5bJA=; b=V5Xxjj01rwxohA69FqToybtkzl5syv4IfWI7y5ph9eg53Tc0c5g7cQFUSaZkCWsj+04MZo5kQHNHQ pbv+IC9+0x6demgpZW+7C1Tuoa45bDmDpKjoXcKAXoCQTTiwiaX/iZUaRvJExAzUyHQCovHqaLYGyy X8rByfL0+CbaQeD2H4PPQ36Qzw5lH6qPYDhrYvLRMQPeV9VwYtnmZt7YphaD/LFvOC4IKHZYbaSPN/ khCevnF9R4TYO9Ja23NX0bC5+yK3lIkmiPCXsCv0h9uT+Nmhuw4X52pJT9bFbIPlLM+JMvInLH/CpS 8h1FMcF27Y4lzOBXuCDEUX3QeGG/duw== X-MHO-RoutePath: aGlwcGll X-MHO-User: 24b2fc5f-d347-11e9-b67d-cdd75d6ce7a8 X-Report-Abuse-To: https://support.duocircle.com/support/solutions/articles/5000540958-duocircle-standard-smtp-abuse-information X-Originating-IP: 67.177.211.60 X-Mail-Handler: DuoCircle Outbound SMTP Received: from ilsoft.org (unknown [67.177.211.60]) by outbound3.ore.mailhop.org (Halon) with ESMTPSA id 24b2fc5f-d347-11e9-b67d-cdd75d6ce7a8; Mon, 09 Sep 2019 21:16:57 +0000 (UTC) Received: from rev (rev [172.22.42.240]) by ilsoft.org (8.15.2/8.15.2) with ESMTP id x89LGqjV063776; Mon, 9 Sep 2019 15:16:52 -0600 (MDT) (envelope-from ian@freebsd.org) Message-ID: Subject: Re: ntpd segfaults on start From: Ian Lepore To: Cy Schubert , Konstantin Belousov Cc: "Rodney W. Grimes" , Harlan Stenn , Vladimir Zakharov , freebsd-current@freebsd.org Date: Mon, 09 Sep 2019 15:16:52 -0600 In-Reply-To: <201909091928.x89JSZMm062482@slippy.cwsent.com> References: <201909091630.x89GUjGX044288@gndrsh.dnsmgr.net> <20190909184446.GU2559@kib.kiev.ua> <201909091928.x89JSZMm062482@slippy.cwsent.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 FreeBSD GNOME Team Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 46S1FS33sJz4fxD X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-2.00 / 15.00]; local_wl_from(0.00)[freebsd.org]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; TAGGED_RCPT(0.00)[]; ASN(0.00)[asn:16509, ipnet:54.186.0.0/15, country:US] X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 09 Sep 2019 21:17:00 -0000 On Mon, 2019-09-09 at 12:28 -0700, Cy Schubert wrote: > > > > On the other hand, the code execution times are not predictable if the > > process's pages can be paged out. Under severe load next instruction > > might take several seconds or even minutes to start. It is quite unlike > > the scheduler delays. That introduces a jitter in the local time > > measurements and their usage as done in userspace. Wouldn't this affect > > the accuracy ? > > IMO it would and would be unacceptable when used as a stratum N server or > with some OLTP or database applications. Locking a few megabytes is a small > cost. What I proposed was changing the default to not lock all of ntpd into memory, because I think that would work well for most users. Admins running stratum 1 or 2 servers are probably a bit more savvy about ntp configuration than the average user, and would use the rlimit command in ntp.conf. -- Ian