[PATCH 3/5] hung_task: Convert process iteration to use for_each_process_thread()

From: Frederic Weisbecker
Date: Wed Apr 09 2014 - 12:15:37 EST


do_each_thread/while_each_thread iterators are deprecated by
for_each_thread/for_each_process_thread() APIs.

Lets convert the callers in the hung task detector code. The ultimate
goal is to remove the struct task_struct::thread_group field and
the corresponding do_each_thread/while_each_thread iterators that are
RCU unsafe.

It also makes the hung task threads iteration eventually RCU safe.

Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
kernel/hung_task.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 06bb141..d19744b 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -157,7 +157,7 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout)
{
int max_count = sysctl_hung_task_check_count;
int batch_count = HUNG_TASK_BATCHING;
- struct task_struct *g, *t;
+ struct task_struct *p, *t;

/*
* If the system crashed already then all bets are off,
@@ -167,18 +167,18 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout)
return;

rcu_read_lock();
- do_each_thread(g, t) {
+ for_each_process_thread(p, t) {
if (!max_count--)
goto unlock;
if (!--batch_count) {
batch_count = HUNG_TASK_BATCHING;
- if (!rcu_lock_break(g, t))
+ if (!rcu_lock_break(p, t))
goto unlock;
}
/* use "==" to skip the TASK_KILLABLE tasks waiting on NFS */
if (t->state == TASK_UNINTERRUPTIBLE)
check_hung_task(t, timeout);
- } while_each_thread(g, t);
+ }
unlock:
rcu_read_unlock();
}
--
1.8.3.1

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