From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx117.postini.com [74.125.245.117]) by kanga.kvack.org (Postfix) with SMTP id 414B96B0027 for ; Tue, 9 Apr 2013 15:54:25 -0400 (EDT) Date: Tue, 9 Apr 2013 12:54:23 -0700 From: Andrew Morton Subject: Re: [PATCH] mm: remove compressed copy from zram in-memory Message-Id: <20130409125423.19592f11e44345df2bca6cfd@linux-foundation.org> In-Reply-To: <20130409010231.GA3467@blaptop> References: <1365400862-9041-1-git-send-email-minchan@kernel.org> <20130408141710.1a1f76a0054bba49a42c76ca@linux-foundation.org> <20130409010231.GA3467@blaptop> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Hugh Dickins , Seth Jennings , Nitin Gupta , Konrad Rzeszutek Wilk , Shaohua Li , Dan Magenheimer On Tue, 9 Apr 2013 10:02:31 +0900 Minchan Kim 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org