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Date: Wed, 20 Jan 2016 16:00:19 +0900
From: Minchan Kim <minchan@kernel.org>
To: Russell Knize <rknize@motorola.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        Junil Lee <junil0814.lee@lge.com>,
        Andrew Morton <akpm@linux-foundation.org>, ngupta@vflare.org,
        linux-mm@kvack.org,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] zsmalloc: fix migrate_zspage-zs_free race condition
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Hello Russ,

On Tue, Jan 19, 2016 at 09:47:12AM -0600, Russell Knize wrote:
>    Just wanted to ack this, as we have been seeing the same problem (weird
>    race conditions during compaction) and fixed it in the same way a few
>    weeks ago (resetting the pin bit before recording the obj).
>    Russ

First of all, thanks for your comment.

The patch you tested have a problem although it's really subtle(ie,
it doesn't do store tearing when I disassemble ARM{32|64}) but it
could have a problem potentially for other architecutres or future ARM.
For right fix, I sent v5 - https://lkml.org/lkml/2016/1/18/263.
If you can prove it fixes your problem, please Tested-by to the thread.
It's really valuable to do testing for stable material.

Thanks!