[PATCH] remove the pointless BUG_ON(!task) from wake_up_q()

[PATCH] remove the pointless BUG_ON(!task) from wake_up_q()

[Oleg Nesterov]

because it looks very confusing (to me at least). It is equivalent to
BUG_ON(node == offsetof(struct task_struct, wake_q)), unlikely this is
what we actually want to check.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 kernel/sched/core.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5226cc26a095..61d1d85bb93d 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -585,7 +585,6 @@ void wake_up_q(struct wake_q_head *head)
 		struct task_struct *task;
 
 		task = container_of(node, struct task_struct, wake_q);
-		BUG_ON(!task);
 		/* Task can safely be re-inserted now: */
 		node = node->next;
 		task->wake_q.next = NULL;
-- 
2.25.1.362.g51ebf55

[tip: sched/core] sched/core: Remove the pointless BUG_ON(!task) from wake_up_q()

[tip-bot2 for Oleg Nesterov]

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     2b8ca1a907d5fffc85fb648bbace28ddf3420825
Gitweb:        https://git.kernel.org/tip/2b8ca1a907d5fffc85fb648bbace28ddf3420825
Author:        Oleg Nesterov <oleg@redhat.com>
AuthorDate:    Mon, 10 May 2021 18:15:22 +02:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Wed, 12 May 2021 11:03:54 +02:00

sched/core: Remove the pointless BUG_ON(!task) from wake_up_q()

container_of() can never return NULL - so don't check for it pointlessly.

[ mingo: Twiddled the changelog. ]

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210510161522.GA32644@redhat.com
---
 kernel/sched/core.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5226cc2..61d1d85 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -585,7 +585,6 @@ void wake_up_q(struct wake_q_head *head)
 		struct task_struct *task;
 
 		task = container_of(node, struct task_struct, wake_q);
-		BUG_ON(!task);
 		/* Task can safely be re-inserted now: */
 		node = node->next;
 		task->wake_q.next = NULL;