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| author | Cyrill Gorcunov <gorcunov@openvz.org> | 2012-06-01 03:26:43 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-06-01 04:49:32 +0400 |
| commit | 818411616baf46ceba0cff6f05af3a9b294734f7 (patch) | |
| tree | b6e338e20d4a45b6a05ffa37e6af33e0cc1b50c0 /fs/proc/base.c | |
| parent | 98ed57eef9f67dfe541be0bca34660ffc88365b2 (diff) | |
| download | linux-818411616baf46ceba0cff6f05af3a9b294734f7.tar.xz | |
fs, proc: introduce /proc/<pid>/task/<tid>/children entry
When we do checkpoint of a task we need to know the list of children the
task, has but there is no easy and fast way to generate reverse
parent->children chain from arbitrary <pid> (while a parent pid is
provided in "PPid" field of /proc/<pid>/status).
So instead of walking over all pids in the system (creating one big
process tree in memory, just to figure out which children a task has) --
we add explicit /proc/<pid>/task/<tid>/children entry, because the kernel
already has this kind of information but it is not yet exported.
This is a first level children, not the whole process tree.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc/base.c')
| -rw-r--r-- | fs/proc/base.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index bd8b4ca6a610..616f41a7cde6 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -3400,6 +3400,9 @@ static const struct pid_entry tid_base_stuff[] = { ONE("stat", S_IRUGO, proc_tid_stat), ONE("statm", S_IRUGO, proc_pid_statm), REG("maps", S_IRUGO, proc_tid_maps_operations), +#ifdef CONFIG_CHECKPOINT_RESTORE + REG("children", S_IRUGO, proc_tid_children_operations), +#endif #ifdef CONFIG_NUMA REG("numa_maps", S_IRUGO, proc_tid_numa_maps_operations), #endif |