From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 583156B0033 for ; Mon, 23 Jan 2017 02:13:27 -0500 (EST) Received: by mail-pf0-f198.google.com with SMTP id d134so192040813pfd.0 for ; Sun, 22 Jan 2017 23:13:27 -0800 (PST) Received: from mail-pg0-x241.google.com (mail-pg0-x241.google.com. [2607:f8b0:400e:c05::241]) by mx.google.com with ESMTPS id c23si14800560pli.184.2017.01.22.23.13.26 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 22 Jan 2017 23:13:26 -0800 (PST) Received: by mail-pg0-x241.google.com with SMTP id 75so12985868pgf.3 for ; Sun, 22 Jan 2017 23:13:26 -0800 (PST) Date: Mon, 23 Jan 2017 16:13:39 +0900 From: Sergey Senozhatsky Subject: Re: [PATCH] mm: extend zero pages to same element pages for zram Message-ID: <20170123071339.GD2327@jagdpanzerIV.localdomain> References: <1483692145-75357-1-git-send-email-zhouxianrong@huawei.com> <1484296195-99771-1-git-send-email-zhouxianrong@huawei.com> <20170121084338.GA405@jagdpanzerIV.localdomain> <84073d07-6939-b22d-8bda-4fa2a9127555@huawei.com> <20170123025826.GA24581@js1304-P5Q-DELUXE> <20170123040347.GA2327@jagdpanzerIV.localdomain> <20170123062716.GF24581@js1304-P5Q-DELUXE> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170123062716.GF24581@js1304-P5Q-DELUXE> Sender: owner-linux-mm@kvack.org List-ID: To: Joonsoo Kim Cc: Sergey Senozhatsky , zhouxianrong , linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, sergey.senozhatsky@gmail.com, minchan@kernel.org, ngupta@vflare.org, Mi.Sophia.Wang@huawei.com, zhouxiyu@huawei.com, weidu.du@huawei.com, zhangshiming5@huawei.com, won.ho.park@huawei.com On (01/23/17 15:27), Joonsoo Kim wrote: > Hello, > > Think about following case in 64 bits kernel. > > If value pattern in the page is like as following, we cannot detect > the same page with 'unsigned int' element. > > AAAAAAAABBBBBBBBAAAAAAAABBBBBBBB... > > 4 bytes is 0xAAAAAAAA and next 4 bytes is 0xBBBBBBBB and so on. yep, that's exactly the case that I though would be broken with a 4-bytes pattern matching. so my conlusion was that for 4 byte pattern we would have working detection anyway, for 8 bytes patterns we might have some extra matching. not sure if it matters that much though. -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