Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762104AbXE1KdR (ORCPT ); Mon, 28 May 2007 06:33:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751519AbXE1KdJ (ORCPT ); Mon, 28 May 2007 06:33:09 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:36090 "EHLO amd.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751288AbXE1KdI (ORCPT ); Mon, 28 May 2007 06:33:08 -0400 Date: Mon, 28 May 2007 12:33:02 +0200 From: Pavel Machek To: "Rafael J. Wysocki" Cc: LKML , Andrew Morton , Gautham R Shenoy , Linus Torvalds , Nigel Cunningham , Oleg Nesterov Subject: Re: [RFC][PATCH][EXPERIMENTAL] Make kernel threads nonfreezable by default Message-ID: <20070528103302.GD18807@elf.ucw.cz> References: <200705270012.59177.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200705270012.59177.rjw@sisk.pl> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.11+cvs20060126 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1544 Lines: 35 Hi! > Index: linux-2.6.22-rc3/Documentation/power/kernel_threads.txt > =================================================================== > --- linux-2.6.22-rc3.orig/Documentation/power/kernel_threads.txt > +++ linux-2.6.22-rc3/Documentation/power/kernel_threads.txt > @@ -1,13 +1,22 @@ > -KERNEL THREADS > +The Freezer and Kernel Threads > > - > -Freezer > - > -Upon entering a suspended state the system will freeze all > -tasks. This is done by delivering pseudosignals. This affects > -kernel threads, too. To successfully freeze a kernel thread > -the thread has to check for the pseudosignal and enter the > -refrigerator. Code to do this looks like this: > +Before entering a system-wide suspend state as well as before creating a > +hibernation snapshot image the system will freeze all tasks, which is done > +by delivering fake signals. This affects kernel threads too, but they won't be > +frozen unless they declare that they want to. For this purpose Well... and unless thread that does disk writes or DMA _wants_ to, you have nice disk corruption... It should be pointed out that it is not voluntary for those types of threads. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/