From 4636c3a8b690c3568d8335b59f5db16ede36e4b8 Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@gmail.com>
Date: Thu, 15 Apr 2021 17:42:48 +0800
Subject: [PATCH] tasks: add put_task_struct_many()

mainline inclusion
from mainline-5.9-rc1
commit dd6f843a9fca8f225c86fee5f50da429c369c045
category: feature
bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27
CVE: NA
---------------------------

put_task_struct_many() is as put_task_struct() but puts several
references at once. Useful to batching it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Conflicts:
	include/linux/sched/task.h
[ec1d281923cf ("sched/core: Convert task_struct.usage to refcount_t)"
not merge]

Signed-off-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>
---
 include/linux/sched/task.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index 44c6f15800ff..d744b385108e 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -98,6 +98,12 @@ static inline void put_task_struct(struct task_struct *t)
 		__put_task_struct(t);
 }
 
+static inline void put_task_struct_many(struct task_struct *t, int nr)
+{
+	if (atomic_sub_and_test(nr, &t->usage))
+		__put_task_struct(t);
+}
+
 struct task_struct *task_rcu_dereference(struct task_struct **ptask);
 
 #ifdef CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT
-- 
GitLab