Messages in this thread Patch in this message | | | Date | Tue, 18 Nov 2014 22:30:29 +0100 | From | Oleg Nesterov <> | Subject | [PATCH 6/6] exit: reparent: introduce find_alive_thread() |
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Add the new simple helper to factor out the for_each_thread() code in find_child_reaper() and find_new_reaper(). It can also simplify the potential PF_EXITING -> exit_state change, plus perhaps we can change this code to take SIGNAL_GROUP_EXIT into account.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> --- kernel/exit.c | 32 +++++++++++++++++++------------- 1 files changed, 19 insertions(+), 13 deletions(-)
diff --git a/kernel/exit.c b/kernel/exit.c index 00c6139..4e3475d 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -459,6 +459,17 @@ static void exit_mm(struct task_struct *tsk) clear_thread_flag(TIF_MEMDIE); } +static struct task_struct *find_alive_thread(struct task_struct *p) +{ + struct task_struct *t; + + for_each_thread(p, t) { + if (!(t->flags & PF_EXITING)) + return t; + } + return NULL; +} + static struct task_struct *find_child_reaper(struct task_struct *father) __releases(&tasklist_lock) __acquires(&tasklist_lock) @@ -469,9 +480,8 @@ static struct task_struct *find_child_reaper(struct task_struct *father) if (likely(reaper != father)) return reaper; - for_each_thread(father, reaper) { - if (reaper->flags & PF_EXITING) - continue; + reaper = find_alive_thread(father); + if (reaper) { pid_ns->child_reaper = reaper; return reaper; } @@ -497,16 +507,13 @@ static struct task_struct *find_child_reaper(struct task_struct *father) static struct task_struct *find_new_reaper(struct task_struct *father, struct task_struct *child_reaper) { - struct task_struct *thread; + struct task_struct *thread, *reaper; - for_each_thread(father, thread) { - if (thread->flags & PF_EXITING) - continue; + thread = find_alive_thread(father); + if (thread) return thread; - } if (father->signal->has_child_subreaper) { - struct task_struct *reaper; /* * Find the first ->is_child_subreaper ancestor in our pid_ns. * We start from father to ensure we can not look into another @@ -520,10 +527,9 @@ static struct task_struct *find_new_reaper(struct task_struct *father, break; if (!reaper->signal->is_child_subreaper) continue; - for_each_thread(reaper, thread) { - if (!(thread->flags & PF_EXITING)) - return thread; - } + thread = find_alive_thread(reaper); + if (thread) + return thread; } } -- 1.5.5.1
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