From: Christoph Lameter <clameter@sgi.com>
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@suse.de>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
Andrew Morton <akpm@linux-foundation.org>,
GOTO <y-goto@jp.fujitsu.com>
Subject: Re: Warning on memory offline (and possible in usual migration?)
Date: Thu, 24 Apr 2008 12:11:07 -0700 (PDT) [thread overview]
Message-ID: <Pine.LNX.4.64.0804241208470.27853@schroedinger.engr.sgi.com> (raw)
In-Reply-To: <20080424103659.90a1006d.kamezawa.hiroyu@jp.fujitsu.com>
On Thu, 24 Apr 2008, KAMEZAWA Hiroyuki wrote:
> > So its safe to migrate a !Uptodate page if it contains buffers? Note that
> > the migration code reattaches the buffer to the new page in
> > buffer_migrate_page().
> >
> I think it's safe because it reattaches buffers as you explained.
>
> under migration
> 1. a page is locked.
> 2. buffers are reattached.
> 3. a PG_writeback page are not migrated.
>
> So, it seems safe.
Concurrent DMA reads cannot occur while we migrate? What holds off
potential I/O to the page? The page lock? Or some buffer lock?
Not that the "buffers" are segments of the page that is migrated.
If concurrent transfers occur while we copy the page then we may see data
corruption.
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next prev parent reply other threads:[~2008-04-24 19:11 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-04-14 5:58 KAMEZAWA Hiroyuki
2008-04-14 17:46 ` Christoph Lameter
2008-04-15 10:13 ` KAMEZAWA Hiroyuki
2008-04-15 19:31 ` Christoph Lameter
2008-04-16 0:23 ` KAMEZAWA Hiroyuki
2008-04-16 2:23 ` KAMEZAWA Hiroyuki
2008-04-16 3:10 ` KAMEZAWA Hiroyuki
2008-04-16 5:22 ` KAMEZAWA Hiroyuki
2008-04-16 18:04 ` Christoph Lameter
2008-04-16 11:00 ` KAMEZAWA Hiroyuki
2008-04-16 18:36 ` Andrew Morton
2008-04-17 0:19 ` KAMEZAWA Hiroyuki
2008-04-17 6:38 ` Warning on memory offline (possible in migration ?) KAMEZAWA Hiroyuki
2008-04-17 6:43 ` Andrew Morton
2008-04-17 6:55 ` KAMEZAWA Hiroyuki
2008-04-22 4:41 ` Warning on memory offline (and possible in usual migration?) Nick Piggin
2008-04-22 4:52 ` Nick Piggin
2008-04-22 7:56 ` KAMEZAWA Hiroyuki
2008-04-22 9:43 ` Nick Piggin
2008-04-22 9:57 ` KAMEZAWA Hiroyuki
2008-04-22 19:16 ` Christoph Lameter
2008-04-23 0:48 ` Nick Piggin
2008-04-23 1:37 ` KAMEZAWA Hiroyuki
2008-04-23 2:41 ` KAMEZAWA Hiroyuki
2008-04-23 2:53 ` Nick Piggin
2008-04-23 3:44 ` KAMEZAWA Hiroyuki
2008-04-23 15:28 ` Nick Piggin
2008-04-24 1:34 ` KAMEZAWA Hiroyuki
2008-04-23 17:50 ` Christoph Lameter
2008-04-24 1:36 ` KAMEZAWA Hiroyuki
2008-04-24 19:11 ` Christoph Lameter [this message]
2008-04-25 0:11 ` KAMEZAWA Hiroyuki
2008-04-23 17:47 ` Christoph Lameter
2008-04-24 2:13 ` Nick Piggin
2008-04-29 7:20 ` KAMEZAWA Hiroyuki
2008-04-30 6:56 ` Nick Piggin
2008-04-30 7:04 ` KAMEZAWA Hiroyuki
2008-04-30 7:12 ` Andrew Morton
2008-04-30 7:22 ` KAMEZAWA Hiroyuki
2008-04-30 7:26 ` Nick Piggin
2008-04-30 17:59 ` Christoph Lameter
2008-04-30 18:01 ` Christoph Lameter
2008-05-01 1:44 ` Nick Piggin
2008-05-01 19:25 ` Christoph Lameter
2008-05-02 0:44 ` Nick Piggin
2008-05-02 1:07 ` Christoph Lameter
2008-05-02 1:23 ` Nick Piggin
2008-05-02 1:37 ` Christoph Lameter
2008-05-02 21:16 ` Christoph Lameter
2008-05-05 4:27 ` Nick Piggin
2008-05-05 17:28 ` Christoph Lameter
2008-05-06 8:52 ` Nick Piggin
2008-05-06 17:49 ` Christoph Lameter
2008-04-30 23:29 ` kamezawa.hiroyu
2008-05-01 0:34 ` Badari Pulavarty
2008-05-01 8:36 ` kamezawa.hiroyu
2008-04-22 4:50 ` Nick Piggin
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