From owner-freebsd-current@FreeBSD.ORG Wed Jul 18 00:14:37 2007 Return-Path: X-Original-To: current@freebsd.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 9B7B616A401 for ; Wed, 18 Jul 2007 00:14:37 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from mail-out3.apple.com (mail-out3.apple.com [17.254.13.22]) by mx1.freebsd.org (Postfix) with ESMTP id 80DB213C491 for ; Wed, 18 Jul 2007 00:14:37 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from relay5.apple.com (relay5.apple.com [17.128.113.35]) by mail-out3.apple.com (Postfix) with ESMTP id 635D1C00664; Tue, 17 Jul 2007 17:14:37 -0700 (PDT) Received: from relay5.apple.com (unknown [127.0.0.1]) by relay5.apple.com (Symantec Mail Security) with ESMTP id 3F3D729C003; Tue, 17 Jul 2007 17:14:37 -0700 (PDT) X-AuditID: 11807123-a7f42bb000000b34-95-469d5b6d8290 Received: from [17.214.13.96] (cswiger1.apple.com [17.214.13.96]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by relay5.apple.com (Apple SCV relay) with ESMTP id 2B5E830400C; Tue, 17 Jul 2007 17:14:37 -0700 (PDT) In-Reply-To: <09BFF2FA5EAB4A45B6655E151BBDD9030483F161@NT-IRVA-0750.brcm.ad.broadcom.com> References: <09BFF2FA5EAB4A45B6655E151BBDD9030483F161@NT-IRVA-0750.brcm.ad.broadcom.com> Mime-Version: 1.0 (Apple Message framework v752.2) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: <2E0C9A04-678B-4C44-9D2E-5500F2C08FE7@mac.com> Content-Transfer-Encoding: 7bit From: Chuck Swiger Date: Tue, 17 Jul 2007 17:14:36 -0700 To: David Christensen X-Mailer: Apple Mail (2.752.2) X-Brightmail-Tracker: AAAAAA== Cc: current@freebsd.org Subject: Re: Getting/Forcing Greater than 4KB Buffer Allocations X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 18 Jul 2007 00:14:37 -0000 On Jul 17, 2007, at 4:54 PM, David Christensen wrote: > I'm investigating a problem with my bce driver which occurs when I ask > for a jumbo mbuf cluster (through m_cljget()). When I map the > memory for DMA I > normally get 3 memory segments (4KB + 4KB + 1KB) on my system, but > on another > user's system he's seeing 2 memory segments (8KB + 1KB). Is there a > configurationoption that allows this or some other tuning variable > involved? The > system is a Xeon dual-core processor and has 8GB of RAM, running an > AMD64 version of > the kernel. Hi, Dave-- Is "sysctl hw.pagesize" different on the two systems? It sure looks like the first machine is using a 4KB pagesize, whereas the second machine is using an 8KB pagesize... -- -Chuck