From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id 2DA806B0033 for ; Sun, 22 Jan 2017 23:03:36 -0500 (EST) Received: by mail-pf0-f200.google.com with SMTP id 201so187634109pfw.5 for ; Sun, 22 Jan 2017 20:03:36 -0800 (PST) Received: from mail-pf0-x243.google.com (mail-pf0-x243.google.com. [2607:f8b0:400e:c00::243]) by mx.google.com with ESMTPS id l8si14340644pln.291.2017.01.22.20.03.35 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 22 Jan 2017 20:03:35 -0800 (PST) Received: by mail-pf0-x243.google.com with SMTP id 19so9109466pfo.3 for ; Sun, 22 Jan 2017 20:03:35 -0800 (PST) Date: Mon, 23 Jan 2017 13:03:47 +0900 From: Sergey Senozhatsky Subject: Re: [PATCH] mm: extend zero pages to same element pages for zram Message-ID: <20170123040347.GA2327@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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170123025826.GA24581@js1304-P5Q-DELUXE> Sender: owner-linux-mm@kvack.org List-ID: To: Joonsoo Kim Cc: zhouxianrong , Sergey Senozhatsky , 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 11:58), Joonsoo Kim wrote: > Hello, > > On Sun, Jan 22, 2017 at 10:58:38AM +0800, zhouxianrong wrote: > > 1. memset is just set a int value but i want to set a long value. > > Sorry for late review. > > Do we really need to set a long value? I cannot believe that > long value is repeated in the page. Value repeatition is > usually done by value 0 or 1 and it's enough to use int. And, I heard > that value 0 or 1 is repeated in Android. Could you check the distribution > of the value in the same page? Hello Joonsoo, thanks for taking a look and for bringing this question up. so I kinda wanted to propose union of `ulong handle' with `uint element' and switching to memset(), but I couldn't figure out if that change would break detection of some patterns. /* Allocated for each disk page */ struct zram_table_entry { - unsigned long handle; + union { + unsigned long handle; + unsigned int element; + }; unsigned long value; }; -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