On Mon, 2008-07-07 at 15:58 -0700, Matt Helsley wrote: > This patchset reuses the container infrastructure and the swsusp freezer to > freeze a group of tasks. > > The freezer subsystem in the container filesystem defines a file named > freezer.state. Writing "FROZEN" to the state file will freeze all tasks in the > cgroup. Subsequently writing "RUNNING" will unfreeze the tasks in the cgroup. > Reading will return the current state. > > * Examples of usage : > > # mkdir /containers/freezer > # mount -t cgroup -ofreezer,signal freezer /containers > # mkdir /containers/0 > # echo $some_pid > /containers/0/tasks > > to get status of the freezer subsystem : > > # cat /containers/0/freezer.state > RUNNING > > to freeze all tasks in the container : > > # echo FROZEN > /containers/0/freezer.state > # cat /containers/0/freezer.state > FREEZING > # cat /containers/0/freezer.state > FROZEN > > to unfreeze all tasks in the container : > > # echo RUNNING > /containers/0/freezer.state > # cat /containers/0/freezer.state > RUNNING > > to kill all tasks in the container : > > # echo 9 > /containers/0/signal.kill > > I've reworked Cedric's patches to use task_lock() to protect access to the > task's cgroup. > > Paul, Pavel asked me to send these to Rafael next. They are patches to make > the freezer useful for checkpoint/restart using cgroups so it would be nice > to get an explicit [N]Ack from you first. > > Rafael, if Paul agrees, please consider applying these patches. > > Changes since v3: > v4 (Almost all of these changes are confined to patch 3): > Reworked the series to use task_lock() instead of RCU. > Reworked the series to use write_string() and read_seq_string() > cgroup methods. FYI - This means these patches need Paul's patches introducing write_string(). I can certainly restore the old code for .read and .write, but I was anticipating write_string() making it into various trees first. If that's not necessarily the case please let me know. Cheers, -Matt _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
