From: Waiman Long <waiman.long@hp.com>
To: "Jörn Engel" <joern@logfs.org>
Cc: Andi Kleen <andi@firstfloor.org>,
"J. Bruce Fields" <bfields@fieldses.org>,
Dave Chinner <david@fromorbit.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Jeff Layton <jlayton@redhat.com>,
Miklos Szeredi <mszeredi@suse.cz>, Ian Kent <raven@themaw.net>,
Sage Weil <sage@inktank.com>, Steve French <sfrench@samba.org>,
Trond Myklebust <Trond.Myklebust@netapp.com>,
Eric Paris <eparis@redhat.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
autofs@vger.kernel.org, ceph-devel@vger.kernel.org,
linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org,
"Chandramouleeswaran, Aswin" <aswin@hp.com>,
"Norton, Scott J" <scott.norton@hp.com>
Subject: Re: [PATCH 0/3 v3] dcache: make it more scalable on large system
Date: Thu, 30 May 2013 11:48:50 -0400 [thread overview]
Message-ID: <51A774E2.9050307@hp.com> (raw)
In-Reply-To: <20130529211917.GB6658@logfs.org>
On 05/29/2013 05:19 PM, Jörn Engel wrote:
> On Wed, 29 May 2013 22:37:00 +0200, Andi Kleen wrote:
>>> As Dave said before, is the last path component sufficient? Or how
>>> about an inode number?
>> Neither works, the profiler needs to find the file and read it.
> Ignoring all the complexity this would cause downstream, you could do
> the path lookup just once, attach some cookie to it and return the
> cookie ever-after. Maybe some combination of i_sb and i_ino would be
> good enough as a cookie.
Still, it is just shifting the complexity from the d_path code to the
perf kernel subsystem as it needs to keep track of what paths have been
sent up before. It also have complications in case the tracked files are
being deleted or moved around in the filesystem. Some kind of
notification mechanism has to be implemented in the dentry layer to
notify the perf subsystem.
Regards,
Longman
next prev parent reply other threads:[~2013-05-30 15:49 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-23 1:37 [PATCH 0/3 v3] dcache: make it more scalable on large system Waiman Long
2013-05-23 1:37 ` [PATCH 1/3 v3] dcache: Don't take unnecessary lock in d_count update Waiman Long
2013-05-23 1:37 ` Waiman Long
2013-05-23 1:37 ` [PATCH 2/3 v3] dcache: introduce a new sequence read/write lock type Waiman Long
2013-05-23 1:37 ` Waiman Long
2013-05-23 1:37 ` [PATCH 3/3 v3] dcache: change rename_lock to a sequence read/write lock Waiman Long
2013-05-23 1:37 ` Waiman Long
2013-05-23 9:42 ` [PATCH 0/3 v3] dcache: make it more scalable on large system Dave Chinner
2013-05-23 21:34 ` Waiman Long
2013-05-27 2:09 ` Dave Chinner
2013-05-29 15:55 ` Waiman Long
2013-05-29 16:13 ` Andi Kleen
2013-05-29 20:23 ` Waiman Long
2013-05-29 16:18 ` Simo Sorce
2013-05-29 16:56 ` Andi Kleen
2013-05-29 17:03 ` Simo Sorce
2013-05-29 20:37 ` Waiman Long
2013-05-29 20:32 ` Waiman Long
2013-05-29 18:46 ` J. Bruce Fields
2013-05-29 20:37 ` Andi Kleen
2013-05-29 20:43 ` J. Bruce Fields
2013-05-29 21:01 ` Andi Kleen
2013-05-29 21:19 ` Jörn Engel
2013-05-30 15:48 ` Waiman Long [this message]
2013-05-30 15:11 ` Jörn Engel
2013-06-06 3:48 ` Dave Chinner
2013-05-29 20:40 ` Waiman Long
-- strict thread matches above, loose matches on Subject: below --
2013-05-23 1:37 Waiman Long
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=51A774E2.9050307@hp.com \
--to=waiman.long@hp.com \
--cc=Trond.Myklebust@netapp.com \
--cc=andi@firstfloor.org \
--cc=aswin@hp.com \
--cc=autofs@vger.kernel.org \
--cc=bfields@fieldses.org \
--cc=ceph-devel@vger.kernel.org \
--cc=david@fromorbit.com \
--cc=eparis@redhat.com \
--cc=jlayton@redhat.com \
--cc=joern@logfs.org \
--cc=linux-cifs@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nfs@vger.kernel.org \
--cc=mszeredi@suse.cz \
--cc=raven@themaw.net \
--cc=sage@inktank.com \
--cc=scott.norton@hp.com \
--cc=sfrench@samba.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).