From owner-freebsd-current Mon Dec 20 16:19:15 1999 Delivered-To: freebsd-current@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [216.240.41.2]) by hub.freebsd.org (Postfix) with ESMTP id 112EE1502D for ; Mon, 20 Dec 1999 16:19:14 -0800 (PST) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id QAA62510; Mon, 20 Dec 1999 16:19:06 -0800 (PST) (envelope-from dillon) Date: Mon, 20 Dec 1999 16:19:06 -0800 (PST) From: Matthew Dillon Message-Id: <199912210019.QAA62510@apollo.backplane.com> To: Greg Lehey Cc: FreeBSD current users Subject: Re: Recent current hangs frequently for 1 to 2 seconds. References: <19991219143759.C465@freebie.lemis.com> <199912190416.UAA01125@apollo.backplane.com> <19991221095213.L440@freebie.lemis.com> Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :Thanks. I've put in the patch, but I'm still seeing the problems. It :seems to be related to SCSI activity (I'm currently performing a :backup on a DLT drive, and apart from that very little disk I/O). Any :other ideas? It seems to me as if the whole system freezes :(keystrokes don't echo, for example), so possibly something is going :into splhigh for too long. : :Greg No, this is very odd. Certainly reading from disk should not cause any blockages. But DLT & SCSI -- there are lots of possiblities there. Is the DLT device sharing the same SCSI bus as the disks? I've historically had bad luck with a shared arrangement and now always put SCSI tape units on their own SCSI bus. If the SCSI bus is hanging something should show up in the kernel logs or dmesg output. Another possibility is that the SCSI operation is causing a hangup or bringing out a bug in the networking somewhere. A lockup for a second or two could be an indication of packet loss. Haven't there been a couple of mbuf-related commits recently? It would be something to look review, anyway. -Matt Matthew Dillon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message