From owner-freebsd-current@FreeBSD.ORG Mon Jan 14 15:09:43 2008 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D73A916A421; Mon, 14 Jan 2008 15:09:43 +0000 (UTC) (envelope-from philip@paeps.cx) Received: from gateway.nixsys.be (gateway.nixsys.be [IPv6:2001:6f8:32f::42]) by mx1.freebsd.org (Postfix) with ESMTP id 6A9E813C458; Mon, 14 Jan 2008 15:09:43 +0000 (UTC) (envelope-from philip@paeps.cx) Received: from wotan.home.paeps.cx (wotan.home.paeps.cx [IPv6:2001:6f8:32f:10:a00:20ff:fe9b:138c]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "wotan.home.paeps.cx", Issuer "NixSys CA" (verified OK)) by gateway.nixsys.be (Postfix) with ESMTP id B02D04050; Mon, 14 Jan 2008 16:09:42 +0100 (CET) Received: from fasolt.home.paeps.cx (fasolt.home.paeps.cx [IPv6:2001:6f8:32f:10:214:5eff:feca:2496]) by wotan.home.paeps.cx (Postfix) with ESMTP id EA04761FB; Mon, 14 Jan 2008 16:09:40 +0100 (CET) Received: from fasolt.home.paeps.cx (philip@localhost [127.0.0.1]) by fasolt.home.paeps.cx (8.14.2/8.14.2) with ESMTP id m0EF9eib026790; Mon, 14 Jan 2008 16:09:40 +0100 (CET) (envelope-from philip@fasolt.home.paeps.cx) Received: (from philip@localhost) by fasolt.home.paeps.cx (8.14.2/8.14.2/Submit) id m0EF9eix026789; Mon, 14 Jan 2008 16:09:40 +0100 (CET) (envelope-from philip) Date: Mon, 14 Jan 2008 16:09:40 +0100 From: Philip Paeps To: John Baldwin Message-ID: <20080114150940.GO17508@fasolt.home.paeps.cx> Mail-Followup-To: John Baldwin , Kris Kennaway , jls@freebsd.org, current@freebsd.org References: <478A739F.2030003@FreeBSD.org> <20080114110054.GK17508@fasolt.home.paeps.cx> <200801140920.12890.jhb@freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <200801140920.12890.jhb@freebsd.org> X-PGP-Fingerprint: 356B AE02 4763 F739 2FA2 E438 2649 E628 C5D3 4D05 X-Date: Today is Prickle-Prickle, the 14th day of Chaos in the YOLD 3174 X-Date-in-France: Quintidi 25 =?utf-8?B?Tml2w7Rz?= =?utf-8?Q?e?= CCXVI, jour du chat X-Date-in-Rome: ante diem XIX Kalendas Februarias MMDCCLXI ab Urbe Condida X-Phase-of-Moon: The Moon is Waxing Crescent (37% of Full) X-Message-Flag: Get a proper mailclient! Organization: Happily Disorganized User-Agent: Mutt/1.5.17 (2007-11-01) Cc: jls@freebsd.org, current@freebsd.org Subject: Re: mpsafe psm driver needed 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: Mon, 14 Jan 2008 15:09:43 -0000 On 2008-01-14 09:20:11 (-0500), John Baldwin wrote: > On Monday 14 January 2008 06:00:54 am Philip Paeps wrote: > > On 2008-01-13 21:25:03 (+0100), Kris Kennaway wrote: > > > I've been looking at some mutex profiling traces from users of 6.x and 7.x > > > who are reporting that their mouse pointer sometimes freezes when their > > > system is busy. In most of the situations I have looked at this is because > > > the psm driver is Giant-locked, and competes with other things like the > > > syncer (in 6.x), or sysctl calls (I have a WIP for this that I need to > > > revisit). > > > > > > This is a minor problem from a grand architectural point of view but an > > > important one from a usability point of view. I believe these particular > > > interactivity problems would be resolved if the psm driver no longer > > > required Giant. Is anyone able to work on this? > > > > I have taken a look at this in the past. It's not a trivial problem. > > > > There is a lot of what I can only charitably call "legacy code" in psm and it > > appears that as soon as you touch any of it, it upsets at least one brand of > > KVM "out there". > > > > One of my mentees has been working on a rewrite for a while, but the project > > has not yet been committed to cvs. > > > > jls: any news on this? > > Does psm(4) interface with any subsystems like tty(4)? It shouldn't. moused(8) listens on /dev/psm and sends events down again to syscons with /dev/consctl. (And syscons then pushes them back up through /dev/sysmouse for things like X11 to listen on - yikes). - Philip -- Philip Paeps Please don't Cc me, I am philip@freebsd.org subscribed to the list. lo azz lo azz gah lo foo