[PATCH] proc: add a schedule point in proc_pid_readdir()

[Eric Dumazet]

From: Eric Dumazet <eduma...@google.com>

We have seen proc_pid_readdir() invocations holding cpu for more
than 50 ms. Add a cond_resched() to be gentle with other tasks.

Signed-off-by: Eric Dumazet <eduma...@google.com>
---
 fs/proc/base.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 8e7e61b28f31..f204f80d397b 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -3179,6 +3179,7 @@ int proc_pid_readdir(struct file *file, struct 
dir_context *ctx)
             iter.tgid += 1, iter = next_tgid(ns, iter)) {
                char name[PROC_NUMBUF];
                int len;
+               cond_resched();
                if (!has_pid_permissions(ns, iter.task, 2))
                        continue;