linux-kernel - Re: [PATCH] mm: remove compressed copy from zram in-memory

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20130409125423.19592f11e44345df2bca6cfd@linux-foundation.org>
Date:	Tue, 9 Apr 2013 12:54:23 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Minchan Kim <minchan@...nel.org>
Cc:	linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	Hugh Dickins <hughd@...gle.com>,
	Seth Jennings <sjenning@...ux.vnet.ibm.com>,
	Nitin Gupta <ngupta@...are.org>,
	Konrad Rzeszutek Wilk <konrad@...nok.org>,
	Shaohua Li <shli@...nel.org>,
	Dan Magenheimer <dan.magenheimer@...cle.com>
Subject: Re: [PATCH] mm: remove compressed copy from zram in-memory

On Tue, 9 Apr 2013 10:02:31 +0900 Minchan Kim <minchan@...nel.org> wrote:

> > Also, what's up with the SWP_BLKDEV test?  zram doesn't support
> > SWP_FILE?  Why on earth not?
> > 
> > Putting swap_slot_free_notify() into block_device_operations seems
> > rather wrong.  It precludes zram-over-swapfiles for all time and means
> > that other subsystems cannot get notifications for swap slot freeing
> > for swapfile-backed swap.
> 
> Zram is just pseudo-block device so anyone can format it with any FSes
> and swapon a file. In such case, he can't get a benefit from
> swap_slot_free_notify. But I think it's not a severe problem because
> there is no reason to use a file-swap on zram. If anyone want to use it,
> I'd like to know the reason. If it's reasonable, we have to rethink a
> wheel and it's another story, IMHO.

My point is that making the swap_slot_free_notify() callback a
blockdev-specific thing was restrictive.  What happens if someone wants
to use it for swapfile-backed swap?  This has nothing to do with zram.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/