From 087806b1281563e4ae7a5bce3155f894af5f4118 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 22 Jun 2011 23:10:26 +0200 Subject: redefine thread_group_leader() as exit_signal >= 0 Change de_thread() to set old_leader->exit_signal = -1. This is good for the consistency, it is no longer the leader and all sub-threads have exit_signal = -1 set by copy_process(CLONE_THREAD). And this allows us to micro-optimize thread_group_leader(), it can simply check exit_signal >= 0. This also makes sense because we should move ->group_leader from task_struct to signal_struct. Signed-off-by: Oleg Nesterov Reviewed-by: Tejun Heo diff --git a/fs/exec.c b/fs/exec.c index 8dca45b..c3d517b 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -963,6 +963,7 @@ static int de_thread(struct task_struct *tsk) leader->group_leader = tsk; tsk->exit_signal = SIGCHLD; + leader->exit_signal = -1; BUG_ON(leader->exit_state != EXIT_ZOMBIE); leader->exit_state = EXIT_DEAD; diff --git a/include/linux/sched.h b/include/linux/sched.h index 39acee2..b38ed51 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2284,8 +2284,10 @@ static inline int get_nr_threads(struct task_struct *tsk) return tsk->signal->nr_threads; } -/* de_thread depends on thread_group_leader not being a pid based check */ -#define thread_group_leader(p) (p == p->group_leader) +static inline bool thread_group_leader(struct task_struct *p) +{ + return p->exit_signal >= 0; +} /* Do to the insanities of de_thread it is possible for a process * to have the pid of the thread group leader without actually being -- cgit v0.10.2