The patch titled
Subject: change thread_group_empty() to use task_struct->thread_node
has been added to the -mm mm-nonmm-unstable branch. Its filename is
change-thread_group_empty-to-use-task_struct-thread_node.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/change-thread_group_empty-to-use-task_struct-thread_node.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Subject: change thread_group_empty() to use task_struct->thread_node
Date: Sat, 26 Aug 2023 13:14:06 +0200
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@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20230826111406.GA23238@xxxxxxxxxx
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/sched/signal.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/include/linux/sched/signal.h~change-thread_group_empty-to-use-task_struct-thread_node
+++ a/include/linux/sched/signal.h
@@ -723,7 +723,8 @@ static inline struct task_struct *next_t
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) \
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
change-thread_group_empty-to-use-task_struct-thread_node.patch
kill-task_struct-thread_group.patch
