From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f53.google.com (mail-pa0-f53.google.com [209.85.220.53]) by kanga.kvack.org (Postfix) with ESMTP id 8D8516B0038 for ; Mon, 2 Feb 2015 00:59:26 -0500 (EST) Received: by mail-pa0-f53.google.com with SMTP id kx10so78003515pab.12 for ; Sun, 01 Feb 2015 21:59:26 -0800 (PST) Received: from mail-pa0-x235.google.com (mail-pa0-x235.google.com. [2607:f8b0:400e:c03::235]) by mx.google.com with ESMTPS id t3si22348920pdc.177.2015.02.01.21.59.25 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sun, 01 Feb 2015 21:59:25 -0800 (PST) Received: by mail-pa0-f53.google.com with SMTP id kx10so78003415pab.12 for ; Sun, 01 Feb 2015 21:59:25 -0800 (PST) Date: Mon, 2 Feb 2015 14:59:23 +0900 From: Sergey Senozhatsky Subject: Re: [PATCH v1 2/2] zram: remove init_lock in zram_make_request Message-ID: <20150202055923.GA332@swordfish> References: <20150202034100.GF6402@blaptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150202034100.GF6402@blaptop> Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Sergey Senozhatsky , Sergey Senozhatsky , Andrew Morton , "linux-kernel@vger.kernel.org" , Linux-MM , Nitin Gupta , Jerome Marchand , Ganesh Mahendran On (02/02/15 12:41), Minchan Kim wrote: > > If we use zram as block device itself(not a fs or swap) and open the > > block device as !FMODE_EXCL, bd_holders will be void. > > > > Another topic: As I didn't see enough fs/block_dev.c bd_holders in zram > > would be mess. I guess we need to study hotplug of device and implement > > it for zram reset rather than strange own konb. It should go TODO. :( > > Actually, I thought bd_mutex use from custom driver was terrible idea > so we should walk around with device hotplug but as I look through > another drivers, they have used the lock for a long time. > Maybe it's okay to use it in zram? > If so, Ganesh's patch is no problem to me although I didn't' review it in detail. > One thing I want to point out is that it would be better to change bd_holders > with bd_openers to filter out because dd test opens block device as !EXCL > so bd_holders will be void. > > What do you think about it? > a quick idea: can we additionally move all bd flush and put work after zram_reset_device(zram, true) and, perhaps, replace ->bd_holders with something else? zram_reset_device() will not return until we have active IOs, pending IOs will be invalidated by ->disksize != 0. -ss -- 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