Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936157Ab3DITy0 (ORCPT ); Tue, 9 Apr 2013 15:54:26 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:39014 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936042Ab3DITyY (ORCPT ); Tue, 9 Apr 2013 15:54:24 -0400 Date: Tue, 9 Apr 2013 12:54:23 -0700 From: Andrew Morton 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 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> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1277 Lines: 25 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/