From owner-svn-src-head@FreeBSD.ORG Sun Aug 2 19:58:16 2009 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D8E39106566B; Sun, 2 Aug 2009 19:58:16 +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 ABB0A8FC0C; Sun, 2 Aug 2009 19:58:16 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from [192.168.2.101] (host81-155-13-237.range81-155.btcentralplus.com [81.155.13.237]) by cyrus.watson.org (Postfix) with ESMTPSA id 89F4D46B2E; Sun, 2 Aug 2009 15:58:15 -0400 (EDT) Message-Id: <134A728D-F2F4-4951-81D8-704CC2DB6F9F@FreeBSD.org> From: "Robert N. M. Watson" To: Alfred Perlstein In-Reply-To: <20090802192902.GS47463@elvis.mu.org> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v935.3) Date: Sun, 2 Aug 2009 20:58:14 +0100 References: <200907300014.n6U0EZ77086341@svn.freebsd.org> <20090731212140.GK47463@elvis.mu.org> <200908010615.02972.hselasky@c2i.net> <20090802192902.GS47463@elvis.mu.org> X-Mailer: Apple Mail (2.935.3) Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, Navdeep Parhar , Hans Petter Selasky Subject: Re: svn commit: r195960 - in head/sys/dev/usb: . controller input X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 02 Aug 2009 19:58:17 -0000 On 2 Aug 2009, at 20:29, Alfred Perlstein wrote: > * Robert Watson [090801 15:15] wrote: >> >> On Sat, 1 Aug 2009, Hans Petter Selasky wrote: >> >>>>> This has slowed down core dumps very significantly. What used >>>>> to take >>>>> 10-15s on my system now takes around 3 minutes. A simple test >>>>> is to >>>>> break into ddb and "call doadump" with or without this rev. I >>>>> have a >>>>> serial console on this machine and so I can use ddb whether the >>>>> attached >>>>> USB keyboard works or not. >>> >>> It's because there is a DELAY(1000) in the UKBD's polling routine >>> so that >>> key- repeating will work, no magic. >> >> Given a choice between dumping 10x faster and having automatic key >> repeat >> in DDB, I'd lean towards the former. :-) >> > > Robert, and *@freebsd.org, > > Hans should be back in a day or so to address this. If critical I can > probably back out the offending code, but I think it makes sense to > wait a few days more for a more comprehensive fix. That's my feeling too -- however, I think it would be useful to generate a small concept test patch that disables the key repeat behavior and see if it restores some/all performance. Scott's argument suggests only some, but perhaps we'd get quite a bit, which is what we're looking for. We wouldn't commit the patch but it would let us know we're on the right track. Robert