From owner-freebsd-stable Fri Dec 31 16:44: 1 1999 Delivered-To: freebsd-stable@freebsd.org Received: from mass.cdrom.com (castles511.castles.com [208.214.165.75]) by hub.freebsd.org (Postfix) with ESMTP id 33AFC14E95; Fri, 31 Dec 1999 16:43:58 -0800 (PST) (envelope-from msmith@mass.cdrom.com) Received: from mass.cdrom.com (localhost [127.0.0.1]) by mass.cdrom.com (8.9.3/8.9.3) with ESMTP id QAA03440; Fri, 31 Dec 1999 16:49:08 -0800 (PST) (envelope-from msmith@mass.cdrom.com) Message-Id: <200001010049.QAA03440@mass.cdrom.com> X-Mailer: exmh version 2.1.1 10/15/1999 To: Charles Youse Cc: Warner Losh , Mike Smith , Mikhail Teterin , stable@FreeBSD.ORG Subject: Re: Panic: Out of mbuf clusters In-reply-to: Your message of "Fri, 31 Dec 1999 23:53:05 EST." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 31 Dec 1999 16:49:08 -0800 From: Mike Smith Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > Perhaps, then, it would be best to monitor the number of free clusters > and when it hits a low watermark, to allocate more - perhaps by flagging > an AST to obviate allocating clusters from within an interrupt context. This sounds nice until I ask you how you plan to deal with an interrupt storm. 8( At some point, you need to decide what to do when you run out of resources. Just "allocating from a larger pool" has other, massive shortcomings; it allows the networking stack to tie up resources that may be needed by other parts of the system (look at the current discussion inre: massive resource overconsumption by the softupdates code for a contrasting example). Right now, the mbuf management code simply bails out when things get too hard, and most of the code that calls it doesn't deal with that very well. Improving the state of play is a slow process that doesn't lend itself well to 10-minute back-of-the-envelope suggestions (no offence meant). -- \\ Give a man a fish, and you feed him for a day. \\ Mike Smith \\ Tell him he should learn how to fish himself, \\ msmith@freebsd.org \\ and he'll hate you for a lifetime. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message