[PATCH] free_uid() locking improvement

36f57413 · Andrew Morton <[email protected]> · 2006-03-24 03:15:47 -08:00

Reduce lock hold times in free_uid().

Cc: Ingo Molnar <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: David Howells <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: 36f574135e36b86bb6ae794bf1d0fce3efa5601f
Parents: 3cf64b93

Changes

1 files changed · +7 −3

File	Status	Add	Del	Content
kernel/user.c	modified	+7	−3	View file

kernel/user.c

View file

diff --git a/kernel/user.c b/kernel/user.c
index d9deae4..2116642 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -105,15 +105,19 @@ void free_uid(struct user_struct *up)
 {
 	unsigned long flags;
 
+	if (!up)
+		return;
+
 	local_irq_save(flags);
-	if (up && atomic_dec_and_lock(&up->__count, &uidhash_lock)) {
+	if (atomic_dec_and_lock(&up->__count, &uidhash_lock)) {
 		uid_hash_remove(up);
+		spin_unlock_irqrestore(&uidhash_lock, flags);
 		key_put(up->uid_keyring);
 		key_put(up->session_keyring);
 		kmem_cache_free(uid_cachep, up);
-		spin_unlock(&uidhash_lock);
+	} else {
+		local_irq_restore(flags);
 	}
-	local_irq_restore(flags);
 }
 
 struct user_struct * alloc_uid(uid_t uid)