From: Marcelo Tosatti <marcelo.tosatti@cyclades.com>
To: IWAMOTO Toshihiro <iwamoto@valinux.co.jp>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>,
haveblue@us.ibm.com, akpm@osdl.org, linux-mm@kvack.org,
piggin@cyberone.com.au, arjanv@redhat.com,
linux-kernel@vger.kernel.org
Subject: Re: [RFC] memory defragmentation to satisfy high order allocations
Date: Mon, 4 Oct 2004 14:29:48 -0300 [thread overview]
Message-ID: <20041004172948.GM16374@logos.cnet> (raw)
In-Reply-To: <20041004040910.DCE4470A2D@sv1.valinux.co.jp>
On Mon, Oct 04, 2004 at 01:09:10PM +0900, IWAMOTO Toshihiro wrote:
> At Sat, 2 Oct 2004 15:33:49 -0300,
> Marcelo Tosatti wrote:
> >
> > On Sat, Oct 02, 2004 at 06:30:15PM +0900, Hirokazu Takahashi wrote:
> > 3) At migrate_page_common you assume additional page references
> > (page_migratable returning -EAGAIN) means the code should try to writeout
> > the page.
> >
> > Is that assumption always valid?
> >
> > In theory there is no need to writeout pages when migrating them to
> > other zones - they will be copied and the dirty information retained (either
> > in the PageDirty bit or radix tree tag).
>
> It's true only when page->private is NULL. Otherwise writeback is
> necessary to free buffer_head.
You can move the buffer_head's also cant you? Adjusting bh->b_page etc.
Thats what migrate_page_buffer does, no?
Writting pages which contain buffer_head's on memory migration
is really, very bad.
Imagine gigabytes of pages with buffer_head's.
> > I just noticed you do that on further patches (migrate_page_buffer), but AFAICS
> > the writeout remains. Why arent you using migrate_page_buffer yet?
> >
> > I think the final aim should be to remove the need for "pageout()"
> > completly.
>
> Are you going to implement migrate_page_buffer for every file system?
> I don't think it's worthwhile.
>
> > Questions: are there any documents on the memory hotplug userspace tools?
> > Where can I find them?
> >
> > Are Iwamoto's test programs available?
>
> I've put them at the following URL, but I doubt they are useful for
> you; there are no documentation for them.
>
> http://people.valinux.co.jp/~iwamoto/mh/tests/
I'll take a look thanks.
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next prev parent reply other threads:[~2004-10-04 17:29 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-10-01 18:22 Marcelo Tosatti
2004-10-01 20:11 ` Andrew Morton
2004-10-01 19:04 ` Marcelo Tosatti
2004-10-01 21:00 ` Andrew Morton
2004-10-01 21:57 ` Dave Hansen
2004-10-01 23:42 ` Marcelo Tosatti
2004-10-02 1:17 ` Andrew Morton
2004-10-02 9:30 ` Hirokazu Takahashi
2004-10-02 18:33 ` Marcelo Tosatti
2004-10-03 4:13 ` Hirokazu Takahashi
2004-10-03 14:07 ` Marcelo Tosatti
2004-10-03 18:35 ` Hirokazu Takahashi
2004-10-03 19:21 ` Trond Myklebust
2004-10-03 20:03 ` Hirokazu Takahashi
2004-10-03 20:44 ` Trond Myklebust
2004-10-04 13:02 ` Hirokazu Takahashi
2004-10-04 17:24 ` Marcelo Tosatti
2004-10-05 2:53 ` Hirokazu Takahashi
2004-10-07 12:06 ` Marcelo Tosatti
2004-10-08 7:00 ` Hirokazu Takahashi
2004-10-08 10:00 ` Marcelo Tosatti
2004-10-08 12:23 ` Hirokazu Takahashi
2004-10-08 12:41 ` Marcelo Tosatti
2004-10-08 16:52 ` Hirokazu Takahashi
2004-10-08 15:36 ` Marcelo Tosatti
2004-10-12 10:56 ` IWAMOTO Toshihiro
2004-10-12 10:35 ` Marcelo Tosatti
2004-10-12 17:55 ` Hirokazu Takahashi
2004-10-12 14:26 ` Martin J. Bligh
2004-10-12 12:17 ` Marcelo Tosatti
2004-10-12 15:01 ` Dave Hansen
2004-10-04 3:24 ` IWAMOTO Toshihiro
2004-10-04 2:22 ` Dave Hansen
2004-10-05 16:46 ` [PATCH] mhp: transfer dirty tag at radix_tree_replace Marcelo Tosatti
2004-10-05 18:35 ` Dave Hansen
2004-10-06 7:39 ` Hirokazu Takahashi
2004-10-08 8:15 ` Hirokazu Takahashi
2004-10-08 20:36 ` Marcelo Tosatti
2004-10-04 4:09 ` [RFC] memory defragmentation to satisfy high order allocations IWAMOTO Toshihiro
2004-10-04 17:29 ` Marcelo Tosatti [this message]
2004-10-02 2:30 ` Nick Piggin
2004-10-02 3:08 ` Marcelo Tosatti
2004-10-04 8:15 ` Nick Piggin
2004-10-02 2:41 ` Nick Piggin
2004-10-02 3:50 ` Hirokazu Takahashi
2004-10-02 16:06 ` Marcelo Tosatti
2004-10-04 2:38 ` Hiroyuki KAMEZAWA
2004-10-04 17:32 ` Marcelo Tosatti
2004-10-04 6:58 ` Hiroyuki KAMEZAWA
2004-10-07 15:58 ` memory hotplug and mem= Marcelo Tosatti
2004-10-07 18:36 ` Dave Hansen
2004-10-07 17:01 ` Marcelo Tosatti
2004-10-07 19:10 ` Dave Hansen
2004-10-07 20:25 ` Dave Hansen
2004-10-11 16:40 [RFC] memory defragmentation to satisfy high order allocations linux
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