From: Eric Dumazet <edumazet@google.com>
Date: Tue, 21 Aug 2012 13:05:14 +0000 (+0200)
Subject: task_work: add a scheduling point in task_work_run()
X-Git-Tag: firefly_0821_release~3680^2~2173^2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=88ec2789d856056344161aa20420dd37e893b0fe;p=firefly-linux-kernel-4.4.55.git

task_work: add a scheduling point in task_work_run()

It seems commit 4a9d4b02 (switch fput to task_work_add) reintroduced
the problem addressed in commit 944be0b2 (close_files(): add scheduling
point)

If a server process with a lot of files (say 2 million tcp sockets)
is killed, we can spend a lot of time in task_work_run() and trigger
a soft lockup.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

diff --git a/kernel/task_work.c b/kernel/task_work.c
index 91d4e1742a0c..d320d44903bd 100644
--- a/kernel/task_work.c
+++ b/kernel/task_work.c
@@ -75,6 +75,7 @@ void task_work_run(void)
 			p = q->next;
 			q->func(q);
 			q = p;
+			cond_resched();
 		}
 	}
 }