From 7993bc1f4663c0db67bb8f0d98e6678145b387cd Mon Sep 17 00:00:00 2001
From: Roland McGrath <roland@redhat.com>
Date: Tue, 7 Sep 2010 19:36:28 -0700
Subject: [PATCH] execve: improve interactivity with large arguments
This adds a preemption point during the copying of the argument and
environment strings for execve, in copy_strings(). There is already
a preemption point in the count() loop, so this doesn't add any new
points in the abstract sense.
When the total argument+environment strings are very large, the time
spent copying them can be much more than a normal user time slice.
So this change improves the interactivity of the rest of the system
when one process is doing an execve with very large arguments.
Signed-off-by: Roland McGrath <roland@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/exec.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/exec.c b/fs/exec.c
index 1b63237fc6dce..6f2d777431a8c 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -419,6 +419,8 @@ static int copy_strings(int argc, const char __user *const __user *argv,
while (len > 0) {
int offset, bytes_to_copy;
+ cond_resched();
+
offset = pos % PAGE_SIZE;
if (offset == 0)
offset = PAGE_SIZE;
--
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