From owner-freebsd-current@FreeBSD.ORG Fri Mar 6 09:25:40 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9C48D106564A for ; Fri, 6 Mar 2009 09:25:40 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id 553FD8FC0C for ; Fri, 6 Mar 2009 09:25:40 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [65.122.17.41]) by cyrus.watson.org (Postfix) with ESMTPS id CE1E846B46; Fri, 6 Mar 2009 04:25:39 -0500 (EST) Date: Fri, 6 Mar 2009 09:25:39 +0000 (GMT) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: "Wilkinson, Alex" In-Reply-To: <20090306002750.GN94275@stlux503.dsto.defence.gov.au> Message-ID: References: <49AFB9DA.7030105@dva.dyndns.org> <20090305230639.GA21057@jnz.sqrt.ca> <20090306002750.GN94275@stlux503.dsto.defence.gov.au> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-current@freebsd.org Subject: Re: pflogd eats 100% cpu now, updated -current from Feb-4 to Mar-4 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: Fri, 06 Mar 2009 09:25:41 -0000 On Fri, 6 Mar 2009, Wilkinson, Alex wrote: > 0n Thu, Mar 05, 2009 at 05:06:39PM -0600, Christian Peron wrote: > > >We recently turned on zerocopy so it can see some exposure. I will > >look into this. > > Can anyone explain what this actually means ? > > net.bpf.zerocopy_enable: Enable new zero-copy BPF buffer sessions BPF now supports a shared memory buffering scheme between userspace and kernel; when the sysctl is enabled, newly opened /dev/bpf devices will permit configuration of the zero-copy scheme. The sysctl doesn't turn zero-copy on and off per se, since existing configured sessions will continue to use it, but no new zero-copy sessions will be permitted when the sysctl is disabled. However, it sounds like there's some interaction between pflogd and the zero-copy code that requires some debugging... Robert N M Watson Computer Laboratory University of Cambridge