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: v3.6-rc3~15
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=f341861fb0b701139849f8a85c2d3cdff466e8e8;p=linux.git

task_work: add a scheduling point in task_work_run()

It seems commit 4a9d4b024a31 ("switch fput to task_work_add") re-
introduced the problem addressed in 944be0b22472 ("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: Linus Torvalds <torvalds@linux-foundation.org>
---

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();
 		}
 	}
 }