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 91d4e1742a0c4ec1cd8805b6663f5a95b5d42b3b..d320d44903bd0ab8ce3a1dc3e40dee28a26e714f 100644 (file)
--- 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();
                }
        }
 }