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Date: Mon, 19 Aug 2013 13:44:44 +0900
From: Minchan Kim <minchan@kernel.org>
To: Michael wang <wangyun@linux.vnet.ibm.com>
Cc: Mitch Harder <mitch.harder@sabayonlinux.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiang Liu <jiang.liu@huawei.com>, Nitin Gupta <ngupta@vflare.org>,
        Jerome Marchand <jmarchand@redhat.com>, devel@driverdev.osuosl.org
Subject: Re: BUG: scheduling while atomic 3.10.7 in ZRAM Swap
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Hello,

On Mon, Aug 19, 2013 at 12:13:02PM +0800, Michael wang wrote:
> Hi, Mitch
> 
> On 08/17/2013 10:01 PM, Mitch Harder wrote:
> > I'm encountering a BUG while using a ZRAM Swap device.
> > 
> > The call trace seems to involve the changes recently added to 3.10.6
> > by the patch:
> > zram: use zram->lock to protect zram_free_page() in swap free notify path
> > 
> > The hardware is a x86 single CPU AMD Athlon XP system with 1GB RAM.
> > 
> > I'm implementing a 352MB ZRAM swap device, and also have 1GB swap
> > space on the hard disk.
> 
> IMHO, it was caused by that swap_entry_free() was invoked with page
> spin-locked, thus zram_slot_free_notify() should not use rw-lock which
> may goto sleep.
> 
> CC folks related.

Thanks for Ccing me, Michael,

Mitch, It's known problem and it should be fixed by [1] in recent linux-next.

[1] a0c516cbfc, zram: don't grab mutex in zram_slot_free_noity

Thanks for the report!

> 
> Regards,
> Michael Wang
-- 
Kind regards,
Minchan Kim