From: ebiederm@xmission.com (Eric W. Biederman)
To: Benjamin LaHaise <bcrl@lhnet.ca>
Cc: Tejun Heo <tj@kernel.org>, Greg Kroah-Hartman <gregkh@suse.de>,
Kay Sievers <kay.sievers@vrfy.org>,
linux-kernel@vger.kernel.org,
Cornelia Huck <cornelia.huck@de.ibm.com>,
linux-fsdevel@vger.kernel.org,
Eric Dumazet <eric.dumazet@gmail.com>,
Serge Hallyn <serue@us.ibm.com>,
"Eric W. Biederman" <ebiederm@aristanetworks.com>
Subject: Re: [PATCH 3/7] sysfs: Keep an nlink count on sysfs directories.
Date: Mon, 11 Jan 2010 17:23:19 -0800 [thread overview]
Message-ID: <m1hbqs2k1k.fsf@fess.ebiederm.org> (raw)
In-Reply-To: <20100112011245.GM5524@kvack.org> (Benjamin LaHaise's message of "Mon\, 11 Jan 2010 20\:12\:45 -0500")
Benjamin LaHaise <bcrl@lhnet.ca> writes:
> On Mon, Jan 11, 2010 at 05:06:53PM -0800, Eric W. Biederman wrote:
>> I don't see the link count as interesting enough to store more than
>> 16bits for it. Even with 32bits of storage for nlink sysfs would have
>> to have to handle the rollover case as I am doing now. So I don't
>> see any advantage to storing more bits.
>
> I'm not terribly concerned with what value gets returned, but rather about
> how long is spent calculating it. Ideally, new sysfs directory entries
> can be inserted in an O(1) or other reasonable order operation. I'll try
> to find some time to re-run my interface scaling tests with your latest
> changes.
Sounds good. My changes so far have been the easy low hanging fruit.
readdir should be at O(N) and stat etc should all be constant time.
Lookups by name are still O(N), and I'm not ready to look at going
better until after I have network namespace support into sysfs.
Eric
next prev parent reply other threads:[~2010-01-12 1:23 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-11 20:16 [PATCH 0/7] General sysfs enhancements Eric W. Biederman
2010-01-11 20:21 ` [PATCH 1/7] sysfs: Serialize updates to the vfs inode Eric W. Biederman
2010-01-12 5:41 ` Serge E. Hallyn
2010-01-11 20:21 ` [PATCH 2/7] sysfs: Pack sysfs_dirent more tightly Eric W. Biederman
2010-01-12 0:41 ` Tejun Heo
2010-01-11 20:21 ` [PATCH 3/7] sysfs: Keep an nlink count on sysfs directories Eric W. Biederman
2010-01-12 0:46 ` Tejun Heo
2010-01-12 0:53 ` Benjamin LaHaise
2010-01-12 1:06 ` Eric W. Biederman
2010-01-12 1:12 ` Benjamin LaHaise
2010-01-12 1:23 ` Eric W. Biederman [this message]
2010-01-12 6:22 ` Tejun Heo
2010-01-12 15:49 ` Valdis.Kletnieks
2010-01-12 1:02 ` Eric W. Biederman
2010-01-12 5:56 ` Serge E. Hallyn
2010-01-12 8:30 ` Eric W. Biederman
2010-01-12 12:41 ` Cornelia Huck
2010-01-12 15:34 ` Eric W. Biederman
2010-01-11 20:21 ` [PATCH 4/7] sysfs: Implement sysfs_rename_link Eric W. Biederman
2010-01-12 6:24 ` Tejun Heo
2010-01-12 17:30 ` Serge E. Hallyn
2010-01-11 20:21 ` [PATCH 5/7] driver core: Use sysfs_rename_link in device_rename Eric W. Biederman
2010-01-12 6:25 ` Tejun Heo
2010-01-12 17:34 ` Serge E. Hallyn
2010-01-11 20:21 ` [PATCH 6/7] sysfs: Pass super_block to sysfs_get_inode Eric W. Biederman
2010-01-12 17:43 ` Serge E. Hallyn
2010-01-11 20:21 ` [PATCH 7/7] sysfs: Kill unused sysfs_sb variable Eric W. Biederman
2010-01-12 17:43 ` Serge E. Hallyn
2010-01-15 21:37 ` [PATCH 0/7] General sysfs enhancements Greg KH
2010-02-13 3:20 ` [PATCH 0/6] " Eric W. Biederman
2010-02-13 3:22 ` [PATCH 1/6] sysfs: Serialize updates to the vfs inode Eric W. Biederman
2010-02-13 3:22 ` [PATCH 2/6] sysfs: Pack sysfs_dirent more tightly Eric W. Biederman
2010-02-13 3:22 ` [PATCH 3/6] sysfs: Implement sysfs_rename_link Eric W. Biederman
2010-02-13 3:22 ` [PATCH 4/6] driver core: Use sysfs_rename_link in device_rename Eric W. Biederman
2010-02-13 3:22 ` [PATCH 5/6] sysfs: Pass super_block to sysfs_get_inode Eric W. Biederman
2010-02-13 3:22 ` [PATCH 6/6] sysfs: Kill unused sysfs_sb variable Eric W. Biederman
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