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 1C8l9W-0007vs-Nd for user-mode-linux-devel@lists.sourceforge.net; Sat, 18 Sep 2004 12:45:46 -0700 Received: from [12.177.129.25] (helo=ccure.user-mode-linux.org) by sc8-sf-mx1.sourceforge.net with esmtp (TLSv1:DES-CBC3-SHA:168) (Exim 4.41) id 1C8l9V-0007XO-0A for user-mode-linux-devel@lists.sourceforge.net; Sat, 18 Sep 2004 12:45:46 -0700 From: Jeff Dike Subject: Re: [uml-devel] uml, ptrace, and BKL Message-ID: <20040918205024.GA3748@ccure.user-mode-linux.org> References: <20040918033012.GA1618@ccure.user-mode-linux.org> <20040918131814.GA2942@ccure.user-mode-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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: Sat, 18 Sep 2004 16:50:24 -0400 To: Adam Heath Cc: user-mode-linux-devel@lists.sourceforge.net On Sat, Sep 18, 2004 at 01:20:39PM -0500, Adam Heath wrote: > This is true(and something I hadn't considered). But with preemption, it's > possible for multiple threads to be running in the kernel(as I understand it). That's true in any case. The difference with preemption is that a thread can be preempted involuntarily when it's in the kernel. This doesn't really change anything with locking, especially the BKL. That's automatically dropped when a thread calls schedule(), so that if a thread was preempted while holding the BKL, it will drop it during the context switch. > Same for a preemptible box. Again, lock contention only really becomes an issue with lots of processors. So, you may see some contention on a 2P box, but in order for it to be a real problem, you'll probably need a lot more. Jeff ------------------------------------------------------- This SF.Net email is sponsored by: YOU BE THE JUDGE. Be one of 170 Project Admins to receive an Apple iPod Mini FREE for your judgement on who ports your project to Linux PPC the best. Sponsored by IBM. Deadline: Sept. 24. Go here: http://sf.net/ppc_contest.php _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel