From: Josef Bacik <jbacik@fb.com>
To: <linux-fsdevel@vger.kernel.org>, <kernel-team@fb.com>,
<viro@ZenIV.linux.org.uk>, <hch@infradead.org>, <jack@suse.cz>,
<david@fromorbit.com>
Subject: [PATCH 2/8] inode: add hlist_fake to avoid the inode hash lock in evict
Date: Thu, 11 Jun 2015 15:41:07 -0400 [thread overview]
Message-ID: <1434051673-13838-3-git-send-email-jbacik@fb.com> (raw)
In-Reply-To: <1434051673-13838-1-git-send-email-jbacik@fb.com>
Some filesystems don't use the VFS inode hash and fake the fact they
are hashed so that all the writeback code works correctly. However,
this means the evict() path still tries to remove the inode from the
hash, meaning that the inode_hash_lock() needs to be taken
unnecessarily. Hence under certain workloads the inode_hash_lock can
be contended even if the inode is never actually hashed.
To avoid this add hlist_fake to test if the inode isn't actually
hashed to avoid taking the hash lock on inodes that have never been
hashed. Based on Dave Chinner's
inode: add IOP_NOTHASHED to avoid inode hash lock in evict
basd on Al's suggestions. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Jan Kara <jack@suse.cz>
---
include/linux/fs.h | 2 +-
include/linux/list.h | 5 +++++
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 35ec87e..b841718 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2563,7 +2563,7 @@ static inline void insert_inode_hash(struct inode *inode)
extern void __remove_inode_hash(struct inode *);
static inline void remove_inode_hash(struct inode *inode)
{
- if (!inode_unhashed(inode))
+ if (!inode_unhashed(inode) && !hlist_fake(&inode->i_hash))
__remove_inode_hash(inode);
}
diff --git a/include/linux/list.h b/include/linux/list.h
index feb773c..3e3e64a 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -672,6 +672,11 @@ static inline void hlist_add_fake(struct hlist_node *n)
n->pprev = &n->next;
}
+static inline bool hlist_fake(struct hlist_node *h)
+{
+ return h->pprev == &h->next;
+}
+
/*
* Move a list from one list head to another. Fixup the pprev
* reference of the first entry if it exists.
--
2.1.0
next prev parent reply other threads:[~2015-06-11 19:41 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-11 19:41 [PATCH 0/7] super block scalabilit patches V3 Josef Bacik
2015-06-11 19:41 ` [PATCH 1/8] writeback: plug writeback at a high level Josef Bacik
2015-06-17 12:03 ` Christoph Hellwig
2015-06-11 19:41 ` Josef Bacik [this message]
2015-06-17 12:03 ` [PATCH 2/8] inode: add hlist_fake to avoid the inode hash lock in evict Christoph Hellwig
2015-06-11 19:41 ` [PATCH 3/8] inode: convert inode_sb_list_lock to per-sb Josef Bacik
2015-06-17 12:06 ` Christoph Hellwig
2015-06-11 19:41 ` [PATCH 4/8] sync: serialise per-superblock sync operations Josef Bacik
2015-06-17 12:06 ` Christoph Hellwig
2015-06-11 19:41 ` [PATCH 5/8] inode: rename i_wb_list to i_io_list Josef Bacik
2015-06-17 12:06 ` Christoph Hellwig
2015-06-11 19:41 ` [PATCH 6/8] bdi: add a new writeback list for sync Josef Bacik
2015-06-15 14:12 ` Jan Kara
2015-06-16 15:42 ` Josef Bacik
2015-06-17 10:34 ` Jan Kara
2015-06-17 17:55 ` Josef Bacik
2015-06-18 9:28 ` Jan Kara
2015-06-18 22:18 ` [PATCH 6/8 V4] " Josef Bacik
2015-06-19 8:38 ` Jan Kara
2015-06-11 19:41 ` [PATCH 7/8] writeback: periodically trim the writeback list Josef Bacik
2015-06-11 19:41 ` [PATCH 8/8] inode: don't softlockup when evicting inodes Josef Bacik
2015-06-15 14:16 ` Jan Kara
2015-06-11 20:50 ` [PATCH 0/7] super block scalabilit patches V3 Tejun Heo
2015-06-15 21:34 ` Dave Chinner
2015-06-22 2:26 ` [PATCH] sync: wait_sb_inodes() calls iput() with spinlock held (was Re: [PATCH 0/7] super block scalabilit patches V3) Dave Chinner
2015-06-22 16:21 ` Josef Bacik
2015-06-23 23:14 ` Josef Bacik
2015-06-24 0:35 ` Dave Chinner
-- strict thread matches above, loose matches on Subject: below --
2015-06-24 3:23 [PATCH 0/8] super block scalability patches V4 Josef Bacik
2015-06-24 3:23 ` [PATCH 2/8] inode: add hlist_fake to avoid the inode hash lock in evict Josef Bacik
2015-03-20 17:14 [PATCH 0/8] Sync and VFS scalability improvements V2 Josef Bacik
2015-03-20 17:14 ` [PATCH 2/8] inode: add hlist_fake to avoid the inode hash lock in evict Josef Bacik
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1434051673-13838-3-git-send-email-jbacik@fb.com \
--to=jbacik@fb.com \
--cc=david@fromorbit.com \
--cc=hch@infradead.org \
--cc=jack@suse.cz \
--cc=kernel-team@fb.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=viro@ZenIV.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).