From e34a35ee1f52312af130b5ebd42fa28313fc6149 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Sat, 26 Aug 2023 13:14:06 +0200 Subject: change thread_group_empty() to use task_struct->thread_node Patch series "kill task_struct->thread_group". This patch (of 2): It could use list_is_singular() but this way it is cheaper. Plus the thread_group_leader() check makes it clear that thread_group_empty() can only return true if p is a group leader. This was not immediately obvious before this patch. task_struct->thread_group no longer has users, it can die. Link: https://lkml.kernel.org/r/20230826111200.GA22982@redhat.com Link: https://lkml.kernel.org/r/20230826111406.GA23238@redhat.com Signed-off-by: Oleg Nesterov Cc: Eric W. Biederman Cc: Peter Zijlstra Signed-off-by: Andrew Morton --- include/linux/sched/signal.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index cffc882d367f..d7fa3ca2fa53 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -733,7 +733,8 @@ static inline struct task_struct *next_thread(struct task_struct *p) static inline int thread_group_empty(struct task_struct *p) { - return list_empty(&p->thread_group); + return thread_group_leader(p) && + list_is_last(&p->thread_node, &p->signal->thread_head); } #define delay_group_leader(p) \ -- cgit