summaryrefslogtreecommitdiffstats
path: root/fs/proc/base.c
diff options
context:
space:
mode:
authorCyrill Gorcunov <gorcunov@openvz.org>2012-05-31 16:26:43 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-31 17:49:32 -0700
commit818411616baf46ceba0cff6f05af3a9b294734f7 (patch)
treeb6e338e20d4a45b6a05ffa37e6af33e0cc1b50c0 /fs/proc/base.c
parent98ed57eef9f67dfe541be0bca34660ffc88365b2 (diff)
downloadop-kernel-dev-818411616baf46ceba0cff6f05af3a9b294734f7.zip
op-kernel-dev-818411616baf46ceba0cff6f05af3a9b294734f7.tar.gz
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.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index bd8b4ca6..616f41a 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
OpenPOWER on IntegriCloud