From owner-freebsd-current@FreeBSD.ORG Wed Jul 18 00:22:33 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 2B29316A400 for ; Wed, 18 Jul 2007 00:22:33 +0000 (UTC) (envelope-from davidch@broadcom.com) Received: from mms1.broadcom.com (mms1.broadcom.com [216.31.210.17]) by mx1.freebsd.org (Postfix) with ESMTP id 027EC13C49D for ; Wed, 18 Jul 2007 00:22:32 +0000 (UTC) (envelope-from davidch@broadcom.com) Received: from [10.10.64.154] by mms1.broadcom.com with ESMTP (Broadcom SMTP Relay (Email Firewall v6.3.1)); Tue, 17 Jul 2007 17:22:21 -0700 X-Server-Uuid: 6B5CFB92-F616-4477-B110-55F967A57302 Received: by mail-irva-10.broadcom.com (Postfix, from userid 47) id CDEB72AF; Tue, 17 Jul 2007 17:22:21 -0700 (PDT) Received: from mail-irva-8.broadcom.com (mail-irva-8 [10.10.64.221]) by mail-irva-10.broadcom.com (Postfix) with ESMTP id B9CAC2AE; Tue, 17 Jul 2007 17:22:21 -0700 (PDT) Received: from mail-irva-12.broadcom.com (mail-irva-12.broadcom.com [10.10.64.146]) by mail-irva-8.broadcom.com (MOS 3.7.5a-GA) with ESMTP id FMC91037; Tue, 17 Jul 2007 17:22:21 -0700 (PDT) Received: from NT-IRVA-0750.brcm.ad.broadcom.com ( nt-irva-0750.brcm.ad.broadcom.com [10.8.194.64]) by mail-irva-12.broadcom.com (Postfix) with ESMTP id 5747869CA4; Tue, 17 Jul 2007 17:22:21 -0700 (PDT) Content-class: urn:content-classes:message MIME-Version: 1.0 X-MimeOLE: Produced By Microsoft Exchange V6.5 Date: Tue, 17 Jul 2007 17:22:17 -0700 Message-ID: <09BFF2FA5EAB4A45B6655E151BBDD9030483F17F@NT-IRVA-0750.brcm.ad.broadcom.com> In-Reply-To: <2E0C9A04-678B-4C44-9D2E-5500F2C08FE7@mac.com> Thread-Topic: Getting/Forcing Greater than 4KB Buffer Allocations Thread-Index: AcfI0KmJUoA0MDVZTse/aR62BFIKAwAAJm+A References: <09BFF2FA5EAB4A45B6655E151BBDD9030483F161@NT-IRVA-0750.brcm.ad.broadcom.com> <2E0C9A04-678B-4C44-9D2E-5500F2C08FE7@mac.com> From: "David Christensen" To: "Chuck Swiger" X-WSS-ID: 6A8382B71S86947261-01-01 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable 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 00:22:33 -0000 > > I'm investigating a problem with my bce driver which occurs=20 > when I ask > > for a jumbo mbuf cluster (through m_cljget()). When I map the =20 > > memory for DMA I > > normally get 3 memory segments (4KB + 4KB + 1KB) on my system, but =20 > > 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 =20 > > involved? The > > system is a Xeon dual-core processor and has 8GB of RAM,=20 > running an =20 > > AMD64 version of > > the kernel. >=20 > Hi, Dave-- >=20 > Is "sysctl hw.pagesize" different on the two systems? It sure looks =20 > like the first machine is using a 4KB pagesize, whereas the second =20 > machine is using an 8KB pagesize... >=20 That was one of my first questions but they are identical, 4096 bytes. Dave