From: "Jörn Engel" <joern@logfs•org>
To: Eric Dumazet <dada1@cosmosbay•com>
Cc: Ingo Molnar <mingo@elte•hu>,
Christoph Hellwig <hch@infradead•org>,
David Miller <davem@davemloft•net>,
"Rafael J. Wysocki" <rjw@sisk•pl>,
linux-kernel@vger•kernel.org,
"kernel-testers@vger•kernel.org >> Kernel Testers List"
<kernel-testers@vger•kernel.org>, Mike Galbraith <efault@gmx•de>,
Peter Zijlstra <a.p.zijlstra@chello•nl>,
Linux Netdev List <netdev@vger•kernel.org>,
Christoph Lameter <cl@linux-foundation•org>,
linux-fsdevel@vger•kernel.org, Al Viro <viro@ZenIV•linux.org.uk>
Subject: Re: [PATCH v2 5/5] fs: new_inode_single() and iput_single()
Date: Sat, 29 Nov 2008 12:14:53 +0100 [thread overview]
Message-ID: <20081129111452.GB11959@logfs.org> (raw)
In-Reply-To: <49310115.8010306@cosmosbay.com>
On Sat, 29 November 2008 09:45:09 +0100, Eric Dumazet wrote:
>
> +void iput_single(struct inode *inode)
> +{
> + if (atomic_dec_and_test(&inode->i_count)) {
> + destroy_inode(inode);
> + percpu_counter_dec(&nr_inodes);
> + }
> +}
I wonder if it is possible to avoid the atomic_dec_and_test() here, at
least in the common case, and combine it with the atomic_dec_and_test()
of the dentry. A quick look at fs/inode.c indicates that inode->i_count
may never get changed for a SINGLE inode, except during creation or
deletion.
It might be worth to
- remove the conditional from iput_single() and measure that it makes a
difference,
- poison SINGLE inodes with some value and
- put a BUG_ON() in __iget() that checks for the poison value.
I _think_ the BUG_ON() is unnecessary, but at least my brain is not
sufficient to convince me. Can inotify somehow get a hold of a socket?
Or dquot (how insane would that be?)
Jörn
--
Mac is for working,
Linux is for Networking,
Windows is for Solitaire!
-- stolen from dc
next prev parent reply other threads:[~2008-11-29 11:15 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <Pine.LNX.4.64.0811201727070.9089@quilx.com>
[not found] ` <20081121083044.GL16242@elte.hu>
[not found] ` <49267694.1030506@cosmosbay.com>
[not found] ` <20081121.010508.40225532.davem@davemloft.net>
[not found] ` <4926AEDB.10007@cosmosbay.com>
[not found] ` <4926AEDB.10007-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-11-21 15:13 ` [PATCH] fs: pipe/sockets/anon dentries should not have a parent Eric Dumazet
[not found] ` <4926D022.5060008-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-11-21 15:21 ` Ingo Molnar
[not found] ` <20081121152148.GA20388-X9Un+BFzKDI@public.gmane.org>
2008-11-21 15:28 ` Eric Dumazet
[not found] ` <4926D39D.9050603-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-11-21 15:34 ` Ingo Molnar
2008-11-26 23:27 ` [PATCH 0/6] fs: Scalability of sockets/pipes allocation/deallocation on SMP Eric Dumazet
2008-11-27 9:39 ` Christoph Hellwig
2008-11-28 18:03 ` Ingo Molnar
[not found] ` <20081128180318.GL10487-X9Un+BFzKDI@public.gmane.org>
2008-11-28 18:47 ` Peter Zijlstra
2008-11-29 6:38 ` Christoph Hellwig
[not found] ` <20081129063816.GA869-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2008-11-29 8:07 ` Eric Dumazet
2008-11-29 8:43 ` [PATCH v2 0/5] " Eric Dumazet
2008-12-11 22:38 ` [PATCH v3 0/7] " Eric Dumazet
2008-12-11 22:38 ` [PATCH v3 1/7] fs: Use a percpu_counter to track nr_dentry Eric Dumazet
2007-07-24 1:24 ` Nick Piggin
[not found] ` <49419680.8010409-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-12-16 21:04 ` Paul E. McKenney
2008-12-11 22:39 ` [PATCH v3 2/7] fs: Use a percpu_counter to track nr_inodes Eric Dumazet
[not found] ` <4941968E.3020201-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2007-07-24 1:30 ` Nick Piggin
[not found] ` <200707241130.56767.nickpiggin-/E1597aS9LT0CCvOHzKKcA@public.gmane.org>
2008-12-12 5:11 ` Eric Dumazet
2008-12-16 21:10 ` Paul E. McKenney
2008-12-11 22:39 ` [PATCH v3 3/7] fs: Introduce a per_cpu last_ino allocator Eric Dumazet
2007-07-24 1:34 ` Nick Piggin
2008-12-16 21:26 ` Paul E. McKenney
2008-12-11 22:39 ` [PATCH v3 4/7] fs: Introduce SINGLE dentries for pipes, socket, anon fd Eric Dumazet
[not found] ` <494196AA.6080002-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-12-16 21:40 ` Paul E. McKenney
2008-12-11 22:40 ` [PATCH v3 5/7] fs: new_inode_single() and iput_single() Eric Dumazet
2008-12-16 21:41 ` Paul E. McKenney
[not found] ` <493100B0.6090104-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-12-11 22:40 ` [PATCH v3 6/7] fs: struct file move from call_rcu() to SLAB_DESTROY_BY_RCU Eric Dumazet
2007-07-24 1:13 ` Nick Piggin
2008-12-12 2:50 ` Nick Piggin
2008-12-12 4:45 ` Eric Dumazet
[not found] ` <4941EC65.5040903-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-12-12 16:48 ` Eric Dumazet
[not found] ` <494295C6.2020906-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-12-13 2:07 ` Christoph Lameter
[not found] ` <Pine.LNX.4.64.0812121958470.15781-dRBSpnHQED8AvxtiuMwx3w@public.gmane.org>
2008-12-17 20:25 ` Eric Dumazet
2008-12-13 1:41 ` Christoph Lameter
2008-12-11 22:41 ` [PATCH v3 7/7] fs: MS_NOREFCOUNT Eric Dumazet
[not found] ` <492DDB6A.8090806-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-11-27 1:37 ` [PATCH 0/6] fs: Scalability of sockets/pipes allocation/deallocation on SMP Christoph Lameter
[not found] ` <Pine.LNX.4.64.0811261935330.31159-dRBSpnHQED8AvxtiuMwx3w@public.gmane.org>
2008-11-27 6:27 ` Eric Dumazet
[not found] ` <492E3DEF.8030602-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-11-27 14:44 ` Christoph Lameter
2008-11-29 8:43 ` [PATCH v2 1/5] fs: Use a percpu_counter to track nr_dentry Eric Dumazet
2008-11-29 8:43 ` [PATCH v2 2/5] fs: Use a percpu_counter to track nr_inodes Eric Dumazet
2008-11-29 8:44 ` [PATCH v2 4/5] fs: Introduce SINGLE dentries for pipes, socket, anon fd Eric Dumazet
[not found] ` <493100E7.3030907-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-11-29 10:38 ` Jörn Engel
[not found] ` <20081129103836.GA11959-PCqxUs/MD9bYtjvyW6yDsg@public.gmane.org>
2008-11-29 11:14 ` Eric Dumazet
2008-11-29 8:45 ` [PATCH v2 5/5] fs: new_inode_single() and iput_single() Eric Dumazet
2008-11-29 11:14 ` Jörn Engel [this message]
2008-11-29 8:44 ` [PATCH v2 3/5] fs: Introduce a per_cpu last_ino allocator Eric Dumazet
2008-11-26 23:32 ` [PATCH 3/6] " Eric Dumazet
[not found] ` <492DDC88.2050305-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-11-27 9:46 ` Christoph Hellwig
[not found] ` <20081121153453.GA23713-X9Un+BFzKDI@public.gmane.org>
2008-11-26 23:30 ` [PATCH 1/6] fs: Introduce a per_cpu nr_dentry Eric Dumazet
[not found] ` <492DDC0B.8060804-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-11-27 9:41 ` Christoph Hellwig
2008-11-26 23:32 ` [PATCH 4/6] fs: Introduce a per_cpu nr_inodes Eric Dumazet
2008-11-27 9:32 ` Peter Zijlstra
2008-11-27 9:39 ` Peter Zijlstra
2008-11-27 9:48 ` Christoph Hellwig
2008-11-27 10:01 ` Eric Dumazet
2008-11-27 10:07 ` Andi Kleen
2008-11-27 14:46 ` Christoph Lameter
2008-11-26 23:32 ` [PATCH 5/6] fs: Introduce special inodes Eric Dumazet
[not found] ` <492DDC99.5060106-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-11-27 8:20 ` David Miller
2008-11-26 23:32 ` [PATCH 6/6] fs: Introduce kern_mount_special() to mount special vfs Eric Dumazet
[not found] ` <492DDCAB.1070204-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-11-27 8:21 ` David Miller
2008-11-28 9:26 ` Al Viro
[not found] ` <20081128092604.GL28946-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org>
2008-11-28 9:34 ` Al Viro
2008-11-28 18:02 ` Ingo Molnar
2008-11-28 18:58 ` Ingo Molnar
[not found] ` <20081128180220.GK10487-X9Un+BFzKDI@public.gmane.org>
2008-11-28 22:20 ` Eric Dumazet
2008-11-28 22:37 ` Eric Dumazet
2008-11-28 22:43 ` Eric Dumazet
2008-11-27 9:53 ` Christoph Hellwig
[not found] ` <20081127095321.GE13860-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2008-11-27 10:04 ` Eric Dumazet
[not found] ` <492E70B6.70108-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-11-27 10:10 ` Christoph Hellwig
2008-11-21 15:36 ` [PATCH] fs: pipe/sockets/anon dentries should not have a parent Christoph Hellwig
2008-11-21 17:58 ` [PATCH] fs: pipe/sockets/anon dentries should have themselves as parent Eric Dumazet
[not found] ` <4926F6C5.9030108-fPLkHRcR87vqlBn2x/YWAg@public.gmane.org>
2008-11-21 18:43 ` Matthew Wilcox
2008-11-23 3:53 ` Eric Dumazet
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