From: Dave Hansen <dave@linux.vnet.ibm.com>
To: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: John Stoffel <john@stoffel.org>,
Johannes Weiner <jweiner@redhat.com>,
Pekka Enberg <penberg@kernel.org>,
Cyclonus J <cyclonusj@gmail.com>,
Sasha Levin <levinsasha928@gmail.com>,
Christoph Hellwig <hch@infradead.org>,
David Rientjes <rientjes@google.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Konrad Wilk <konrad.wilk@oracle.com>,
Jeremy Fitzhardinge <jeremy@goop.org>,
Seth Jennings <sjenning@linux.vnet.ibm.com>,
ngupta@vflare.org, Chris Mason <chris.mason@oracle.com>,
JBeulich@novell.com, Jonathan Corbet <corbet@lwn.net>
Subject: RE: [GIT PULL] mm: frontswap (for 3.2 window)
Date: Sun, 30 Oct 2011 13:06:02 -0700 [thread overview]
Message-ID: <1320005162.15403.14.camel@nimitz> (raw)
In-Reply-To: <3ac142d4-a4ca-4a24-bf0b-69a90bd1d1a0@default>
On Sun, 2011-10-30 at 12:18 -0700, Dan Magenheimer wrote:
> > since they're the ones who will have to understand this stuff and know
> > how to maintain it. And keeping this maintainable is a key goal.
>
> Absolutely agree. Count the number of frontswap lines that affect
> the current VM core code and note also how they are very clearly
> identified. It really is a very VERY small impact to the core VM
> code (e.g. in the files swapfile.c and page_io.c).
Granted, the impact on the core VM in lines of code is small. But, I
think the behavioral impact is potentially huge since tmem's hooks add
non-trivial amounts of framework underneath the VM in core paths. In
zcache's case, this means a bunch of allocations and an entirely new
allocator memory allocator being used in the swap paths.
We're certainly still shaking bugs out of the interactions there like
with zcache_direct_reclaim_lock. Granted, that's not a
tmem/frontswap/cleancache bug, but it does speak to the difficulty and
subtlety of writing one of those frameworks underneath the tmem API.
-- Dave
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2011-10-30 20:06 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-27 18:52 [GIT PULL] mm: frontswap (for 3.2 window) Dan Magenheimer
[not found] ` <alpine.DEB.2.00.1110271318220.7639@chino.kir.corp.google.com20111027211157.GA1199@infradead.org>
2011-10-27 19:30 ` Kurt Hackel
2011-10-27 20:18 ` David Rientjes
2011-10-27 21:11 ` Christoph Hellwig
2011-10-27 21:49 ` Dan Magenheimer
2011-10-27 21:52 ` Christoph Hellwig
2011-10-27 22:21 ` Dan Magenheimer
2011-10-28 7:12 ` Sasha Levin
[not found] ` <CAOzbF4fnD=CGR-nizZoBxmFSuAjFC3uAHf3wDj5RLneJvJhrOQ@mail.gmail.comCAOJsxLGOTw7rtFnqeHvzFxifA0QgPVDHZzrEo=-uB2Gkrvp=JQ@mail.gmail.com>
[not found] ` <552d2067-474d-4aef-a9a4-89e5fd8ef84f@default20111031181651.GF3466@redhat.com>
[not found] ` <60592afd-97aa-4eaf-b86b-f6695d31c7f1@default20111031223717.GI3466@redhat.com>
[not found] ` <1b2e4f74-7058-4712-85a7-84198723e3ee@default20111101012017.GJ3466@redhat.com>
[not found] ` <6a9db6d9-6f13-4855-b026-ba668c29ddfa@default20111101180702.GL3466@redhat.com>
[not found] ` <b8a0ca71-a31b-488a-9a92-2502d4a6e9bf@default20111102013122.GA18879@redhat.com>
2011-10-28 7:30 ` Cyclonus J
2011-10-28 14:26 ` Pekka Enberg
2011-10-28 15:21 ` Dan Magenheimer
[not found] ` <CAOJsxLEE-qf9me1SAZLFiEVhHVnDh7BDrSx1+abe9R4mfkhD=g@mail.gmail.com20111028163053.GC1319@redhat.com>
2011-10-28 15:36 ` Pekka Enberg
2011-10-28 16:30 ` Johannes Weiner
2011-10-28 17:01 ` Pekka Enberg
2011-10-28 17:07 ` Dan Magenheimer
2011-10-28 18:28 ` John Stoffel
2011-10-28 20:19 ` Dan Magenheimer
2011-10-28 20:52 ` John Stoffel
2011-10-30 19:18 ` Dan Magenheimer
2011-10-30 20:06 ` Dave Hansen [this message]
2011-10-30 21:50 ` Dan Magenheimer
2011-11-02 19:45 ` Rik van Riel
2011-11-02 20:45 ` Dan Magenheimer
2011-11-06 22:32 ` Valdis.Kletnieks
2011-11-08 12:15 ` Ed Tomlinson
2011-10-31 8:12 ` James Bottomley
2011-10-31 15:39 ` Dan Magenheimer
2011-11-01 10:13 ` James Bottomley
2011-11-01 18:10 ` Dan Magenheimer
2011-11-01 18:48 ` Dave Hansen
2011-11-01 21:32 ` Dan Magenheimer
2011-11-02 7:44 ` James Bottomley
2011-11-02 19:39 ` Dan Magenheimer
2011-10-31 18:44 ` Andrea Arcangeli
2011-10-30 21:47 ` Johannes Weiner
2011-10-30 23:19 ` Dan Magenheimer
2011-10-31 18:34 ` Andrea Arcangeli
2011-10-31 21:45 ` Dan Magenheimer
2011-10-28 16:37 ` Dan Magenheimer
2011-10-28 16:59 ` Pekka Enberg
2011-10-28 17:20 ` Dan Magenheimer
2011-10-31 18:16 ` Andrea Arcangeli
2011-10-31 20:58 ` Dan Magenheimer
2011-10-31 22:37 ` Andrea Arcangeli
2011-10-31 23:36 ` Dan Magenheimer
2011-11-01 1:20 ` Andrea Arcangeli
2011-11-01 16:41 ` Dan Magenheimer
2011-11-01 18:07 ` Andrea Arcangeli
2011-11-01 21:00 ` Dan Magenheimer
2011-11-02 1:31 ` Andrea Arcangeli
2011-11-02 19:06 ` Dan Magenheimer
2011-11-03 0:32 ` Andrea Arcangeli
2011-11-03 22:29 ` Dan Magenheimer
2011-11-02 20:51 ` Rik van Riel
2011-11-02 21:14 ` Dan Magenheimer
2011-11-15 16:29 ` Rik van Riel
2011-11-15 17:33 ` Jeremy Fitzhardinge
2011-11-16 14:49 ` Konrad Rzeszutek Wilk
2011-11-01 10:16 ` James Bottomley
2011-11-01 18:21 ` Dan Magenheimer
2011-11-02 8:14 ` James Bottomley
2011-11-02 20:08 ` Dan Magenheimer
2011-11-03 10:30 ` Theodore Tso
2011-11-03 14:59 ` Dan Magenheimer
2011-11-02 15:44 ` Avi Kivity
2011-11-02 16:02 ` Andrea Arcangeli
2011-11-02 16:13 ` Avi Kivity
2011-11-02 20:27 ` Dan Magenheimer
2011-11-02 20:19 ` Dan Magenheimer
2011-10-27 21:44 ` Avi Miller
2011-10-27 22:33 ` Brian King
2011-10-28 5:17 ` Nitin Gupta
2011-10-29 13:43 ` Ed Tomlinson
2011-10-31 8:13 ` KAMEZAWA Hiroyuki
2011-10-31 16:38 ` Dan Magenheimer
2011-11-01 0:50 ` KAMEZAWA Hiroyuki
2011-11-01 15:25 ` Dan Magenheimer
2011-11-01 21:43 ` Andrew Morton
2011-11-01 22:25 ` Dan Magenheimer
2011-11-02 21:03 ` Rik van Riel
2011-11-02 21:42 ` Dan Magenheimer
2011-11-02 1:14 ` KAMEZAWA Hiroyuki
2011-11-02 15:12 ` Dan Magenheimer
2011-11-04 4:19 ` KAMEZAWA Hiroyuki
2011-11-03 16:49 ` Jan Beulich
2011-11-04 0:54 ` Andrew Morton
2011-11-04 8:49 ` Jan Beulich
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=1320005162.15403.14.camel@nimitz \
--to=dave@linux.vnet.ibm.com \
--cc=JBeulich@novell.com \
--cc=akpm@linux-foundation.org \
--cc=chris.mason@oracle.com \
--cc=corbet@lwn.net \
--cc=cyclonusj@gmail.com \
--cc=dan.magenheimer@oracle.com \
--cc=hch@infradead.org \
--cc=jeremy@goop.org \
--cc=john@stoffel.org \
--cc=jweiner@redhat.com \
--cc=konrad.wilk@oracle.com \
--cc=levinsasha928@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=ngupta@vflare.org \
--cc=penberg@kernel.org \
--cc=rientjes@google.com \
--cc=sjenning@linux.vnet.ibm.com \
--cc=torvalds@linux-foundation.org \
/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).