Subject: linux-next: build failure after merge of the userns tree

From: Stephen Rothwell <[email-masked]>
Date: Wed, 16 Mar 2022 16:56:12 +1100

Hi all,

After merging the userns tree, today's linux-next build (powerpc
ppc64_defconfig) failed like this:

kernel/sched/fair.c: In function 'init_numa_balancing':
kernel/sched/fair.c:2884:9: error: implicit declaration of function 'init_task_work'; did you mean 'init_irq_work'? [-Werror=implicit-function-declaration]
 2884 |         init_task_work(&p->numa_work, task_numa_work);
      |         ^~~~~~~~~~~~~~
      |         init_irq_work
kernel/sched/fair.c: In function 'task_tick_numa':
kernel/sched/fair.c:2935:25: error: implicit declaration of function 'task_work_add' [-Werror=implicit-function-declaration]
 2935 |                         task_work_add(curr, work, TWA_RESUME);
      |                         ^~~~~~~~~~~~~
kernel/sched/fair.c:2935:51: error: 'TWA_RESUME' undeclared (first use in this function)
 2935 |                         task_work_add(curr, work, TWA_RESUME);
      |                                                   ^~~~~~~~~~

Maybe caused by commit

  03248addadf1 ("resume_user_mode: Move to resume_user_mode.h")
or
  8ca07e17c9dd ("task_work: Remove unnecessary include from posix_timers.h")

interacting with (maybe) commit

  c4ad6fcb67c4 ("sched/headers: Reorganize, clean up and optimize kernel/sched/fair.c dependencies")

from the tip tree.

I have applied this merge fix patch.

From: Stephen Rothwell <[email-masked]>
Date: Wed, 16 Mar 2022 16:41:42 +1100
Subject: [PATCH] fixup for moving of linux/task_work.h

Signed-off-by: Stephen Rothwell <[email-masked]>
---
 kernel/sched/fair.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 89d21fda106c..7a6678fdffb0 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -31,6 +31,7 @@
 #include <linux/lockdep_api.h>
 #include <linux/softirq.h>
 #include <linux/refcount_api.h>
+#include <linux/task_work.h>
 #include <linux/topology.h>
 #include <linux/sched/clock.h>
 #include <linux/sched/cond_resched.h>
-- 
2.34.1

-- 
Cheers,
Stephen Rothwell