From mboxrd@z Thu Jan 1 00:00:00 1970 From: matthltc-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org Subject: [RFC PATCH 0/4] Container Freezer: Reuse Suspend Freezer Date: Thu, 03 Apr 2008 14:03:16 -0700 Message-ID: <20080403210316.397506379@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Linux-Kernel Cc: Linux Containers List-Id: containers.vger.kernel.org NOTE: Due to problems with my MTA configuration two earlier attempts reached linux-pm but not linux-kernel. Please cc linux-pm-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org on replies. This patchset is a prototype using the container infrastructure and the swsusp freezer to freeze a group of tasks. I've merely taken Cedric's patches, forward-ported them to 2.6.25-rc8-mm1 and done a small amount of testing. 2 files are defined by the freezer subsystem in the container filesystem : * "freezer.freeze" writing 1 will freeze all tasks and 0 unfreeze reading will return the status of the freezer * "freezer.kill" writing will send signal number to all tasks * Usage : # mkdir /containers/freezer # mount -t container -ofreezer freezer /containers/freezer # mkdir /containers/freezer/0 # echo $some_pid > /containers/freezer/0/tasks to get status of the freezer subsystem : # cat /containers/freezer/0/freezer.freeze RUNNING to freeze all tasks in the container : # echo 1 > /containers/freezer/0/freezer.freeze # cat /containers/freezer/0/freezer.freeze FREEZING # cat /containers/freezer/0/freezer.freeze FROZEN to unfreeze all tasks in the container : # echo 1 > /containers/freezer/0/freezer.freeze # cat /containers/freezer/0/freezer.freeze RUNNING to kill all tasks in the container : # echo 9 > /containers/freezer/0/freezer.kill * Caveats: - the FROZEN status is calculated and changed when the container file "freezer.freeze" is read. - frozen containers will be unfrozen when a system is resumed after a suspend. This is addressed by the last patch. * Series Applies to 2.6.25-rc8-mm1 The first patches make the freezer available to all architectures before implementing the freezer subsystem. [RFC PATCH 1/4] Add TIF_FREEZE flag to all architectures [RFC PATCH 2/4] Make refrigerator always available [RFC PATCH 3/4] Implement freezer cgroup subsystem [RFC PATCH 4/4] Skip frozen cgroups during power management resume Each patch compiles, boots, and survives basic LTP containers and controllers tests. Comments are welcome. Cheers, -Matt Helsley --