From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.11] helo=sc8-sf-mx1.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1Dj2r2-0000zQ-Ar for user-mode-linux-devel@lists.sourceforge.net; Thu, 16 Jun 2005 15:28:56 -0700 Received: from lakshmi.addtoit.com ([198.99.130.6] helo=lakshmi.solana.com) by sc8-sf-mx1.sourceforge.net with esmtp (Exim 4.41) id 1Dj2r0-00053c-JO for user-mode-linux-devel@lists.sourceforge.net; Thu, 16 Jun 2005 15:28:56 -0700 From: Jeff Dike Subject: Re: [uml-devel] Recent patches of note Message-ID: <20050616222340.GF9792@ccure.user-mode-linux.org> References: <20050616160728.GA6040@ccure.user-mode-linux.org> <200506162041.27013.blaisorblade@yahoo.it> <42B1C787.6010402@fujitsu-siemens.com> <200506162051.21441.blaisorblade@yahoo.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200506162051.21441.blaisorblade@yahoo.it> Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Thu, 16 Jun 2005 18:23:40 -0400 To: Blaisorblade Cc: user-mode-linux-devel@lists.sourceforge.net, Bodo Stroesser On Thu, Jun 16, 2005 at 08:51:20PM +0200, Blaisorblade wrote: > > And also it makes tt a bit more removable, if Jeff decides to. > Well, on this point I'd be cautious. > > Currently there is no way to even test UML in SMP mode other than using TT > mode, so at least this must be solved. Yeah, we need to provide SMP on skas. That, and the performance of page fault handling were the only two things stopping me from removing tt mode in favor of skas0. Bodo and have talked about this, and it seems that skas0 SMP is impractical because a malicious threaded app could interfere with the stub operation. However, skas3 SMP is quite doable, and I think an unsafe skas0 SMP mode that you can enable with a switch might be OK, too. I've since decided that page fault performance is not a show-stopper. It appears that tt mode is not supportable in recent libcs due to the errno problem. We can get page fault performance back by pushing PTRACE_FAULTINFO into mainline, which should have been done a long time ago. Same for sysemu, BTW. At this point, I'm -><- this close to deciding to get rid of tt mode in 2.6.13 or 2.6.14. I want skas0 in mainline early in 2.6.13 so it can be exercised. Getting skas SMP fixed, and PTRACE_FAULTINFO in mainline would make me happy about trashing tt mode at some later point. Jeff ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel