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	Wed, 19 Mar 2014 12:17:23 -0400
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Date: Wed, 19 Mar 2014 12:20:08 -0400
From: Chris Mason <clm@fb.com>
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To: Marc MERLIN <marc@merlins.org>, <linux-btrfs@vger.kernel.org>
Subject: Re: btrfs-rmw-2: page allocation failure: order:1, mode:0x8020
References: <20140319154513.GQ6143@merlins.org>
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On 03/19/2014 11:45 AM, Marc MERLIN wrote:
> My server died last night during a btrfs send/receive to a btrfs radi5 array
>
> Here are the logs. Is this anything known or with a possible workaround?
>
> Thanks,
> Marc
>
> btrfs-rmw-2: page allocation failure: order:1, mode:0x8020

This is an order 1 atomic allocation from the mvs driver, we really 
should not be depending on that to get IO done.  A quick search and it 
looks like we're allocating MVS_SLOT_BUF_SZ (8192) bytes.

You could try bumping the lowmem reserves.

-chris