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Date: Wed, 19 Mar 2014 10:52:00 -0400
From: Dave Jones <davej@redhat.com>
To: Hugh Dickins <hughd@google.com>
Cc: Sasha Levin <sasha.levin@oracle.com>, Cyrill Gorcunov <gorcunov@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
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        Linus Torvalds <torvalds@linux-foundation.org>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>, Bob Liu <bob.liu@oracle.com>,
        Konstantin Khlebnikov <koct9i@gmail.com>
Subject: Re: bad rss-counter message in 3.14rc5
Message-ID: <20140319145200.GA4608@redhat.com>
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On Tue, Mar 18, 2014 at 07:19:09PM -0700, Hugh Dickins wrote:

 > Another positive on the rss counters, great, thanks Dave.
 > That encourages me to think again on the swapops BUG, but no promises.

So while I slept I ran a test kernel with that swapops BUG replaced with a printk.
I'm not sure of the validity of this, given the state of the kernel afterwards
is somewhat suspect, but I did see in the logs this morning..

[18728.075153] migration_entry_to_page BUG hit
[18728.200705] BUG: Bad rss-counter state mm:ffff880241b3f500 idx:0 val:1 (Not tainted)
[18728.200706] BUG: Bad rss-counter state mm:ffff880241b3f500 idx:1 val:-1 (Not tainted)

This might be collateral damage from the swapops thing, I guess we won't know until
that gets fixed, but I thought I'd mention that we might still have a problem here.

	Dave