All of lore.kernel.org
 help / color / mirror / Atom feed
From: David Rientjes <rientjes@google.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <js1304@gmail.com>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Christoph Lameter <cl@linux.com>, Mel Gorman <mgorman@suse.de>
Subject: Re: [PATCH] mm: fix wrong argument of migrate_huge_pages() in soft_offline_huge_page()
Date: Tue, 17 Jul 2012 15:29:43 -0700 (PDT)	[thread overview]
Message-ID: <alpine.DEB.2.00.1207171526440.23015@chino.kir.corp.google.com> (raw)
In-Reply-To: <20120717134915.76adf9bd.akpm@linux-foundation.org>

On Tue, 17 Jul 2012, Andrew Morton wrote:

> > > Commit a6bc32b899223a877f595ef9ddc1e89ead5072b8 ('mm: compaction: introduce
> > > sync-light migration for use by compaction') change declaration of
> > > migrate_pages() and migrate_huge_pages().
> > > But, it miss changing argument of migrate_huge_pages()
> > > in soft_offline_huge_page(). In this case, we should call with MIGRATE_SYNC.
> > > So change it.
> > > 
> > > Additionally, there is mismatch between type of argument and function
> > > declaration for migrate_pages(). So fix this simple case, too.
> > > 
> > > Signed-off-by: Joonsoo Kim <js1304@gmail.com>
> > 
> > Acked-by: David Rientjes <rientjes@google.com>
> > 
> > Should be cc'd to stable for 3.3+.
> 
> Well, why?  I'm suspecting a switch from MIGRATE_SYNC_LIGHT to
> MIGRATE_SYNC will have no discernable effect.  Unless it triggers hitherto
> unknkown about deadlocks...
> 
> For a -stable backport we should have a description of the end-user
> visible effects of the bug.  This changelog lacked such a description.
> 

I would put this:

MIGRATE_SYNC_LIGHT will not aggressively attempt to defragment memory when 
allocating hugepages for migration with MIGRATE_SYNC_LIGHT, such as not 
defragmenting dirty pages, so MADV_SOFT_OFFLINE and 
/sys/devices/system/memory/soft_offline_page would be significantly 
less successful without this patch.

WARNING: multiple messages have this Message-ID (diff)
From: David Rientjes <rientjes@google.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <js1304@gmail.com>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Christoph Lameter <cl@linux.com>, Mel Gorman <mgorman@suse.de>
Subject: Re: [PATCH] mm: fix wrong argument of migrate_huge_pages() in soft_offline_huge_page()
Date: Tue, 17 Jul 2012 15:29:43 -0700 (PDT)	[thread overview]
Message-ID: <alpine.DEB.2.00.1207171526440.23015@chino.kir.corp.google.com> (raw)
In-Reply-To: <20120717134915.76adf9bd.akpm@linux-foundation.org>

On Tue, 17 Jul 2012, Andrew Morton wrote:

> > > Commit a6bc32b899223a877f595ef9ddc1e89ead5072b8 ('mm: compaction: introduce
> > > sync-light migration for use by compaction') change declaration of
> > > migrate_pages() and migrate_huge_pages().
> > > But, it miss changing argument of migrate_huge_pages()
> > > in soft_offline_huge_page(). In this case, we should call with MIGRATE_SYNC.
> > > So change it.
> > > 
> > > Additionally, there is mismatch between type of argument and function
> > > declaration for migrate_pages(). So fix this simple case, too.
> > > 
> > > Signed-off-by: Joonsoo Kim <js1304@gmail.com>
> > 
> > Acked-by: David Rientjes <rientjes@google.com>
> > 
> > Should be cc'd to stable for 3.3+.
> 
> Well, why?  I'm suspecting a switch from MIGRATE_SYNC_LIGHT to
> MIGRATE_SYNC will have no discernable effect.  Unless it triggers hitherto
> unknkown about deadlocks...
> 
> For a -stable backport we should have a description of the end-user
> visible effects of the bug.  This changelog lacked such a description.
> 

I would put this:

MIGRATE_SYNC_LIGHT will not aggressively attempt to defragment memory when 
allocating hugepages for migration with MIGRATE_SYNC_LIGHT, such as not 
defragmenting dirty pages, so MADV_SOFT_OFFLINE and 
/sys/devices/system/memory/soft_offline_page would be significantly 
less successful without this patch.

--
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/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  reply	other threads:[~2012-07-17 22:29 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-17 17:01 [PATCH] mm: fix wrong argument of migrate_huge_pages() in soft_offline_huge_page() Joonsoo Kim
2012-07-17 17:01 ` Joonsoo Kim
2012-07-17 20:42 ` David Rientjes
2012-07-17 20:42   ` David Rientjes
2012-07-17 20:49   ` Andrew Morton
2012-07-17 20:49     ` Andrew Morton
2012-07-17 22:29     ` David Rientjes [this message]
2012-07-17 22:29       ` David Rientjes
2012-07-18  8:15       ` Aneesh Kumar K.V
2012-07-18  8:15         ` Aneesh Kumar K.V

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=alpine.DEB.2.00.1207171526440.23015@chino.kir.corp.google.com \
    --to=rientjes@google.com \
    --cc=akpm@linux-foundation.org \
    --cc=cl@linux.com \
    --cc=js1304@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mgorman@suse.de \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.