From owner-freebsd-hackers@FreeBSD.ORG Mon Sep 12 21:53:41 2011 Return-Path: Delivered-To: hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A5E4D106566B for ; Mon, 12 Sep 2011 21:53:41 +0000 (UTC) (envelope-from brett@lariat.net) Received: from lariat.net (lariat.net [66.62.230.51]) by mx1.freebsd.org (Postfix) with ESMTP id 60F4D8FC13 for ; Mon, 12 Sep 2011 21:53:41 +0000 (UTC) Received: from WildRover.lariat.net (IDENT:ppp1000.lariat.net@lariat.net [66.119.58.2] (may be forged)) by lariat.net (8.9.3/8.9.3) with ESMTP id PAA20860 for ; Mon, 12 Sep 2011 15:53:38 -0600 (MDT) Message-Id: <201109122153.PAA20860@lariat.net> X-Mailer: QUALCOMM Windows Eudora Version 7.1.0.9 Date: Mon, 12 Sep 2011 15:53:39 -0600 To: hackers@freebsd.org From: Brett Glass In-Reply-To: <14112_1315854090_4E6E570A_14112_184_1_D9B37353831173459FDA A836D3B43499C803FA06@WADPMBXV0.waddell.com> References: <201109111852.MAA08146@lariat.net> <14112_1315854090_4E6E570A_14112_184_1_D9B37353831173459FDAA836D3B43499C803FA06@WADPMBXV0.waddell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed X-Mailman-Approved-At: Mon, 12 Sep 2011 23:24:17 +0000 Cc: Subject: RE: Negative ping times with FreeBSD 8.1-RELEASE on older Celeron system X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 12 Sep 2011 21:53:41 -0000 More information regarding the odd behavior I'm seeing. Turns out that packets do not even need to leave the machine for it to report large negative ping times, on the order of more than half a second. (See below.) Clearly something is odd about timekeeping in this system (SiS motherboard chipset, PII-generation Celeron but still effectively a "686") which was not a problem when it was running FreeBSD 4.11-RELEASE (as it was before). Any ideas? --Brett Glass # ping localhost PING localhost (127.0.0.1): 56 data bytes 64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=-0.148 ms 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=-0.151 ms 64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=-686.111 ms 64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=-0.180 ms 64 bytes from 127.0.0.1: icmp_seq=4 ttl=64 time=0.110 ms 64 bytes from 127.0.0.1: icmp_seq=5 ttl=64 time=686.351 ms 64 bytes from 127.0.0.1: icmp_seq=6 ttl=64 time=-686.376 ms 64 bytes from 127.0.0.1: icmp_seq=7 ttl=64 time=0.121 ms 64 bytes from 127.0.0.1: icmp_seq=8 ttl=64 time=-686.402 ms 64 bytes from 127.0.0.1: icmp_seq=9 ttl=64 time=-686.105 ms 64 bytes from 127.0.0.1: icmp_seq=10 ttl=64 time=686.623 ms 64 bytes from 127.0.0.1: icmp_seq=11 ttl=64 time=0.107 ms 64 bytes from 127.0.0.1: icmp_seq=12 ttl=64 time=0.119 ms 64 bytes from 127.0.0.1: icmp_seq=13 ttl=64 time=0.418 ms 64 bytes from 127.0.0.1: icmp_seq=14 ttl=64 time=0.401 ms 64 bytes from 127.0.0.1: icmp_seq=15 ttl=64 time=-0.169 ms 64 bytes from 127.0.0.1: icmp_seq=16 ttl=64 time=0.113 ms 64 bytes from 127.0.0.1: icmp_seq=17 ttl=64 time=0.401 ms 64 bytes from 127.0.0.1: icmp_seq=18 ttl=64 time=-686.117 ms 64 bytes from 127.0.0.1: icmp_seq=19 ttl=64 time=0.115 ms 64 bytes from 127.0.0.1: icmp_seq=20 ttl=64 time=0.111 ms