From: NeilBrown <neilb@suse.de>
To: Ian Kent <raven@themaw.net>
Cc: autofs@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 6/6] autofs4: don't take spinlock when not needed in autofs4_lookup_expiring
Date: Thu, 10 Jul 2014 09:41:14 +1000 [thread overview]
Message-ID: <20140709234114.4525.70534.stgit@notabene.brown> (raw)
In-Reply-To: <20140709233541.4525.25151.stgit@notabene.brown>
If the expiring_list is empty, we can avoid a costly spinlock
in the rcu-walk path through authfs4_d_manage.
Signed-off-by: NeilBrown <neilb@suse.de>
---
fs/autofs4/root.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 1ad119407e2f..774c2dab331b 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -219,6 +219,8 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry,
const unsigned char *str = name->name;
struct list_head *p, *head;
+ if (list_empty(&sbi->expiring_list))
+ return NULL;
spin_lock(&sbi->lookup_lock);
head = &sbi->expiring_list;
list_for_each(p, head) {
next prev parent reply other threads:[~2014-07-09 23:42 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-09 23:41 [PATCH 0/6] autofs4: support RCU-walk NeilBrown
2014-07-09 23:41 ` [PATCH 3/6] autofs4: allow RCU-walk to walk through autofs4 NeilBrown
2014-07-16 4:44 ` Ian Kent
2014-07-16 5:51 ` NeilBrown
2014-07-16 6:56 ` Ian Kent
2014-07-17 5:00 ` Ian Kent
2014-07-17 8:04 ` NeilBrown
2014-07-17 10:17 ` Ian Kent
2014-07-29 1:51 ` NeilBrown
2014-07-29 6:37 ` Ian Kent
2014-07-09 23:41 ` [PATCH 2/6] autofs4: remove a redundant assignment NeilBrown
2014-07-16 3:27 ` Ian Kent
2014-07-09 23:41 ` [PATCH 5/6] autofs4: avoid taking fs_lock during rcu-walk NeilBrown
2014-07-16 9:52 ` Ian Kent
2014-07-09 23:41 ` NeilBrown [this message]
2014-07-16 3:42 ` [PATCH 6/6] autofs4: don't take spinlock when not needed in autofs4_lookup_expiring Ian Kent
2014-07-16 6:10 ` NeilBrown
2014-07-09 23:41 ` [PATCH 4/6] autofs4: factor should_expire() out of autofs4_expire_indirect NeilBrown
2014-07-14 0:53 ` [PATCH 4/6 v2] " NeilBrown
2014-07-15 3:48 ` Ian Kent
2014-07-15 4:05 ` NeilBrown
2014-07-15 7:44 ` Ian Kent
2014-07-16 7:50 ` Ian Kent
2014-07-17 4:34 ` NeilBrown
2014-07-09 23:41 ` [PATCH 1/6] autofs4: remove unused autofs4_ispending() NeilBrown
2014-07-16 3:26 ` Ian Kent
2014-07-10 7:43 ` [PATCH 0/6] autofs4: support RCU-walk Ian Kent
2014-07-10 7:45 ` Ian Kent
2014-07-10 8:25 ` NeilBrown
2014-07-11 2:49 ` Ian Kent
2014-07-16 3:24 ` Ian Kent
2014-07-16 6:00 ` NeilBrown
2014-07-16 7:21 ` Ian Kent
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