From owner-freebsd-bugs@FreeBSD.ORG Wed Feb 4 13:40:03 2009 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B2C9A106564A for ; Wed, 4 Feb 2009 13:40:03 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id A0FC08FC13 for ; Wed, 4 Feb 2009 13:40:03 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.14.3/8.14.3) with ESMTP id n14De3BO091899 for ; Wed, 4 Feb 2009 13:40:03 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.3/8.14.3/Submit) id n14De3Cs091891; Wed, 4 Feb 2009 13:40:03 GMT (envelope-from gnats) Date: Wed, 4 Feb 2009 13:40:03 GMT Message-Id: <200902041340.n14De3Cs091891@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org From: Martin Birgmeier Cc: Subject: Re: kern/131360: [nfs] poor scaling behavior of the NFS server under load X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Martin Birgmeier List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 04 Feb 2009 13:40:03 -0000 The following reply was made to PR kern/131360; it has been noted by GNATS. From: Martin Birgmeier To: bug-followup@FreeBSD.org Cc: Subject: Re: kern/131360: [nfs] poor scaling behavior of the NFS server under load Date: Wed, 4 Feb 2009 14:38:06 +0100 (CET) I just realized that there might also be an interaction with pppoa2 (from /usr/ports/net/pppoa). The excessive load seems to happen more likely if at the same time I have heavy traffic through my ADSL connection, which goes through an Alcatel ADSL modem, pppoa2, and user-mode ppp. Syslog will continually show the following message: Feb 4 13:56:59 gandalf pppoa2[1491]: write_dest: 11800 ENOBUFS errors Feb 4 13:57:03 gandalf pppoa2[1491]: write_dest: 11900 ENOBUFS errors Feb 4 13:57:08 gandalf pppoa2[1491]: write_dest: 12000 ENOBUFS errors Feb 4 13:57:11 gandalf pppoa2[1491]: write_dest: 12100 ENOBUFS errors Feb 4 13:57:15 gandalf pppoa2[1491]: write_dest: 12200 ENOBUFS errors At the same time, netstat -m shows the following: # netstat -m 233/412/645 mbufs in use (current/cache/total) 207/241/448/25600 mbuf clusters in use (current/cache/total/max) 204/180 mbuf+clusters out of packet secondary zone in use (current/cache) 1/19/20/12800 4k (page size) jumbo clusters in use (current/cache/total/max) 0/0/0/6400 9k jumbo clusters in use (current/cache/total/max) 0/0/0/3200 16k jumbo clusters in use (current/cache/total/max) 476K/661K/1137K bytes allocated to network (current/cache/total) 0/0/0 requests for mbufs denied (mbufs/clusters/mbuf+clusters) 0/0/0 requests for jumbo clusters denied (4k/9k/16k) 0/5/6656 sfbufs in use (current/peak/max) 0 requests for sfbufs denied 0 requests for sfbufs delayed 15 requests for I/O initiated by sendfile 0 calls to protocol drain routines