From owner-freebsd-bugs@FreeBSD.ORG Tue May 17 18:50:21 2005 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3C1F216A4CE for ; Tue, 17 May 2005 18:50:21 +0000 (GMT) Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1ACB343D72 for ; Tue, 17 May 2005 18:50:21 +0000 (GMT) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.13.3/8.13.3) with ESMTP id j4HIo4gk033864 for ; Tue, 17 May 2005 18:50:04 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.13.3/8.13.1/Submit) id j4HIo4is033862; Tue, 17 May 2005 18:50:04 GMT (envelope-from gnats) Date: Tue, 17 May 2005 18:50:04 GMT Message-Id: <200505171850.j4HIo4is033862@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org From: Ernie Smallis Subject: Re: kern/78968: FreeBSD freezes on mbufs exhaustion (network interface independent) X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: Ernie Smallis List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 May 2005 18:50:21 -0000 The following reply was made to PR kern/78968; it has been noted by GNATS. From: Ernie Smallis To: bug-followup@freebsd.org, acid@gemius.pl Cc: Subject: Re: kern/78968: FreeBSD freezes on mbufs exhaustion (network interface independent) Date: Tue, 17 May 2005 11:41:47 -0700 I am seeing this too: The fxp driver is receiving a return of ENOBUFS from m_getcl() (no surprise there). However, since there are no clusters available and the fxp driver has frames to DMA from its FIFO; it keeps calling for clusters which never happens successfully. It appears the system is hung but; in fact, it is in a tight loop. I believe BSD 4.x had a patch that fixed a panic for the exhaustion situation since the code would be de-referencing a NULL pointer. So, now we have a test for NULL and the return of ENOBUFS. That's one way of not seeing the current problem ;-) Another way is to fix this. The test for NULL is certainly appropriate however, what happens next isn't. I am looking to contact the relevant committer(s) for a discussion as to how to resolve this problem. Regards, Ernie ;-)