From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id DF6716B0033 for ; Tue, 24 Jan 2017 23:02:13 -0500 (EST) Received: by mail-pf0-f199.google.com with SMTP id d123so8166811pfd.0 for ; Tue, 24 Jan 2017 20:02:13 -0800 (PST) Received: from mailout1.samsung.com (mailout1.samsung.com. [203.254.224.24]) by mx.google.com with ESMTPS id x40si169714plb.112.2017.01.24.20.02.12 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 24 Jan 2017 20:02:12 -0800 (PST) Received: from epcas1p4.samsung.com (unknown [182.195.41.48]) by mailout1.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0OKB00HPFHVM2U40@mailout1.samsung.com> for linux-mm@kvack.org; Wed, 25 Jan 2017 13:02:10 +0900 (KST) Subject: Re: [Bug 192571] zswap + zram enabled BUG From: Chulmin Kim Message-id: <2059ec0c-d817-9660-9a16-59fe46f3e3a7@samsung.com> Date: Tue, 24 Jan 2017 23:02:30 -0500 MIME-version: 1.0 In-reply-to: Content-type: text/plain; charset=utf-8; format=flowed Content-transfer-encoding: 7bit References: <20170117122249.815342d95117c3f444acc952@linux-foundation.org> <20170118013948.GA580@jagdpanzerIV.localdomain> <1484719121.25232.1.camel@list.ru> <1485216185.5952.2.camel@list.ru> Sender: owner-linux-mm@kvack.org List-ID: To: Dan Streetman , Alexandr Cc: bugzilla-daemon@bugzilla.kernel.org, Linux-MM On 01/24/2017 03:16 PM, Dan Streetman wrote: > On Mon, Jan 23, 2017 at 7:03 PM, Alexandr wrote: >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA512 >> >> >>> Why would you do this? There's no benefit of using zswap together >>> with zram. >> >> i just wanted to test zram and zswap, i still not dig to deep in it, >> but what i wanted is to use zram swap (with zswap disabled), and if it >> exceeded use real swap on block device with zswap enabled. > > I don't believe that's possible, you can't enable zswap for only > specific swap devices; and anyway, if you fill up zram, you won't > really have any memory left for zswap to use will you? > > However, it shouldn't encounter any BUG(), like you saw. If it's > reproducable for you, can you give details on how to reproduce it? > Hello. Mr. Streetman. Regarding to this problem, I have a question on zswap. Is there any reason that zswap_frontswap_load() does not call flush_dcache_page()? The zswap load function can dirty the page mapped to user space (might be shareable/writable) which seems exactly the condition mentioned in the definition of flush_dcache_page(). I'm thinking that flush_dcache_page() should be called in the end of zswap_frontswap_load(). Could you review my opinion? Thanks! Chulmin Kim > -- > 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 > > -- 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