proc: add a schedule point in proc_pid_readdir()

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

[akpm@linux-foundation.org: coding style fix]
Link: http://lkml.kernel.org/r/1484238380.15816.42.camel@edumazet-glaptop3.roam.corp.google.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Eric Dumazet 2017-01-24 15:18:07 -08:00 committed by Linus Torvalds
parent 424f6c4818
commit 3ba4bceef2

View File

@ -3179,6 +3179,8 @@ 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;