From: Eric Paris <eparis@redhat.com>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: John Stoffel <john@stoffel.org>,
linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-fsdevel@vger.kernel.org, hch@infradead.org,
zohar@us.ibm.com, warthog9@kernel.org, david@fromorbit.com,
jmorris@namei.org, kyle@mcmartin.ca, akpm@linux-foundation.org,
torvalds@linux-foundation.org, mingo@elte.hu,
viro@zeniv.linux.org.uk
Subject: Re: [PATCH 06/11] IMA: use i_writecount rather than a private counter
Date: Mon, 25 Oct 2010 18:29:09 -0400 [thread overview]
Message-ID: <1288045749.2655.49.camel@localhost.localdomain> (raw)
In-Reply-To: <4CC603E3.3070405@zytor.com>
On Mon, 2010-10-25 at 15:25 -0700, H. Peter Anvin wrote:
> On 10/25/2010 02:52 PM, Eric Paris wrote:
> > On Mon, 2010-10-25 at 15:27 -0400, John Stoffel wrote:
> >
> >> The problems with kernel.org is a perfect exmaple of how an annocuous
> >> feature like this, can kill a system's performance.
> >
> > You admit that you don't know what you are talking about and then state
> > that this kills systems performance. Interesting conclusion.
> >
> > I'm not going to try to refute you point by point but will instead paint
> > a broad picture. I see 3 possible states:
> > 1) Configured out - 0 overhead. period.
> > 2) Configured in but default disabled
> > 3) Configured in and enabled by admin intervention
> >
> > I have (I think) pretty clearly discussed the overhead and the changes
> > made in case #2. We expand struct inode by 4 bytes, we increment and
> > decrement those 4 bytes on open/close() and we use a new inode->i_flags.
> >
>
> Case #2 is the bad one, as long as distros are likely to compile it in.
Agreed. And that's the case this whole patch series is addressing. It
makes it (literally not figuratively) hundreds of times better than it
is today :)
-Eric
next prev parent reply other threads:[~2010-10-25 22:30 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-25 18:41 [PATCH 01/11] IMA: use rbtree instead of radix tree for inode information cache Eric Paris
2010-10-25 18:41 ` [PATCH 02/11] IMA: drop the inode opencount since it isn't needed for operation Eric Paris
2010-10-25 18:41 ` [PATCH 03/11] IMA: use unsigned int instead of long for counters Eric Paris
2010-10-25 18:41 ` [PATCH 04/11] IMA: convert internal flags from long to char Eric Paris
2010-10-25 18:41 ` [PATCH 05/11] IMA: use inode->i_lock to protect read and write counters Eric Paris
2010-10-25 18:41 ` [PATCH 06/11] IMA: use i_writecount rather than a private counter Eric Paris
2010-10-25 19:27 ` John Stoffel
2010-10-25 21:52 ` Eric Paris
2010-10-25 22:25 ` H. Peter Anvin
2010-10-25 22:29 ` Eric Paris [this message]
2010-10-26 13:57 ` John Stoffel
2010-10-26 13:53 ` John Stoffel
2010-10-26 22:08 ` H. Peter Anvin
2010-10-25 18:41 ` [PATCH 07/11] IMA: move read counter into struct inode Eric Paris
2010-10-25 18:42 ` [PATCH 08/11] IMA: only allocate iint when needed Eric Paris
2010-10-25 18:42 ` [PATCH 09/11] IMA: drop refcnt from ima_iint_cache since it isn't needed Eric Paris
2010-10-25 18:42 ` [PATCH 10/11] IMA: explicit IMA i_flag to remove global lock on inode_delete Eric Paris
2010-10-25 18:42 ` [PATCH 11/11] IMA: fix the ToMToU logic Eric Paris
2010-10-25 19:21 ` [PATCH 01/11] IMA: use rbtree instead of radix tree for inode information cache John Stoffel
2010-10-25 19:38 ` J.H.
2010-10-25 20:55 ` Linus Torvalds
2010-10-25 20:57 ` Christoph Hellwig
2010-10-25 21:11 ` Linus Torvalds
2010-10-26 14:01 ` John Stoffel
2010-10-26 15:22 ` Linus Torvalds
2010-10-26 15:30 ` Eric Paris
2010-10-26 15:53 ` John Stoffel
2010-10-26 18:13 ` Al Viro
2010-10-27 13:35 ` James Morris
2010-10-26 14:07 ` John Stoffel
2010-10-25 21:34 ` Eric Paris
2010-10-26 13:45 ` John Stoffel
2010-10-25 23:22 ` Dave Chinner
2010-10-26 0:12 ` Eric Paris
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=1288045749.2655.49.camel@localhost.localdomain \
--to=eparis@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=david@fromorbit.com \
--cc=hch@infradead.org \
--cc=hpa@zytor.com \
--cc=jmorris@namei.org \
--cc=john@stoffel.org \
--cc=kyle@mcmartin.ca \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=torvalds@linux-foundation.org \
--cc=viro@zeniv.linux.org.uk \
--cc=warthog9@kernel.org \
--cc=zohar@us.ibm.com \
/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).