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 1BQ8lp-0004cL-FZ for user-mode-linux-devel@lists.sourceforge.net; Tue, 18 May 2004 10:52:53 -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 4.30) id 1BQ8lo-00086q-Ry for user-mode-linux-devel@lists.sourceforge.net; Tue, 18 May 2004 10:52:53 -0700 From: Jeff Dike Subject: Re: [uml-devel] preemption Message-ID: <20040518183838.GA29175@ccure.user-mode-linux.org> References: <20040518134726.36369.qmail@web14002.mail.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040518134726.36369.qmail@web14002.mail.yahoo.com> 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: Tue, 18 May 2004 14:38:38 -0400 To: Sam King Cc: user-mode-linux-devel@lists.sourceforge.net On Tue, May 18, 2004 at 06:47:26AM -0700, Sam King wrote: > >From what I can tell, when the guest kernel takes a > timer interrupt (SIGALRM) it eventually updates the > tsk->need_resched parameter for processes that have > been running for too long. However, I do not see > where the actual switch takes place except in the > interrupt_end() function which is only called as a > result of guest application system calls and signals. Exactly. Every kernel entrance is either a system call or signal (a UML signal, not a process signal, BTW), so there is a preemption opportunity at every return to userspace. Jeff ------------------------------------------------------- This SF.Net email is sponsored by: SourceForge.net Broadband Sign-up now for SourceForge Broadband and get the fastest 6.0/768 connection for only $19.95/mo for the first 3 months! http://ads.osdn.com/?ad_id=2562&alloc_id=6184&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