Messages in this thread | | | Date | Mon, 10 Aug 2009 15:26:19 -0700 | From | Sukadev Bhattiprolu <> | Subject | Re: [RFC][v4][PATCH 7/7]: Define clone_with_pids syscall |
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Pavel Machek [pavel@ucw.cz] wrote: | Hi! | | > | > Subject: [RFC][v4][PATCH 7/7]: Define clone_with_pids syscall | > | > Container restart requires that a task have the same pid it had when it was | > checkpointed. When containers are nested the tasks within the containers | > exist in multiple pid namespaces and hence have multiple pids to specify | > during restart. | > | > clone_with_pids(), intended for use during restart, is the same as clone(), | > except that it takes a 'target_pid_set' paramter. This parameter lets caller | > choose specific pid numbers for the child process, in the process's active | > and ancestor pid namespaces. (Descendant pid namespaces in general don't | > matter since processes don't have pids in them anyway, but see comments | > in copy_target_pids() regarding CLONE_NEWPID). | | This should go to documentation/manpage somewhere.
Agree. Will update once we have some consensus on the interface.
The interface defined in this patch 7/7
syscall(__NR_clone_with_pids, flags, stack, NULL, NULL, NULL, &pid_set);
meets the requirements of checkpoint/restart. But as mentioned in patch 0/7, we are just not sure if we should take this opportunity to address the clone-flags limitation so we are not forced to define another flavor of clone() soon.
Sukadev
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