From owner-freebsd-hackers Fri Nov 15 8:36:31 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 365C337B404 for ; Fri, 15 Nov 2002 08:36:30 -0800 (PST) Received: from web.cs.ndsu.nodak.edu (web.cs.ndsu.NoDak.edu [134.129.125.7]) by mx1.FreeBSD.org (Postfix) with ESMTP id 799B643E6E for ; Fri, 15 Nov 2002 08:36:29 -0800 (PST) (envelope-from tinguely@web.cs.ndsu.nodak.edu) Received: (from tinguely@localhost) by web.cs.ndsu.nodak.edu (8.11.4/8.11.4) id gAFGaIP16259; Fri, 15 Nov 2002 10:36:18 -0600 (CST) (envelope-from tinguely) Date: Fri, 15 Nov 2002 10:36:18 -0600 (CST) From: mark tinguely Message-Id: <200211151636.gAFGaIP16259@web.cs.ndsu.nodak.edu> To: chuck_tuffli@agilent.com, freebsd-hackers@FreeBSD.ORG Subject: Re: bus_dmamem_alloc failing In-Reply-To: <20021115141048.GA367@thegrail.rose.agilent.com> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG since the allocated space is larger that a physical page (65536 > 4096), bus_dmamem_alloc() allocates physical contiguous memory. After repeated allocations and frees, the physical memory pages will fragment and the allocation will fail. You may need to rethink your allocation strategy, such as hold some memory allocations static between unloads and loads if your device can take non-physical contiguous memory chunks, use another allocation technique or other imaginative tricks. --Mark Tinguely. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message