From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 6CE166B0033 for ; Fri, 13 Jan 2017 03:07:56 -0500 (EST) Received: by mail-pf0-f197.google.com with SMTP id f144so108375662pfa.3 for ; Fri, 13 Jan 2017 00:07:56 -0800 (PST) Received: from lgeamrelo13.lge.com (LGEAMRELO13.lge.com. [156.147.23.53]) by mx.google.com with ESMTP id u1si8407736plj.178.2017.01.13.00.07.54 for ; Fri, 13 Jan 2017 00:07:55 -0800 (PST) Date: Fri, 13 Jan 2017 17:03:30 +0900 From: Minchan Kim Subject: Re: [PATCH] mm: extend zero pages to same element pages for zram Message-ID: <20170113080330.GB8018@bbox> References: <1483692145-75357-1-git-send-email-zhouxianrong@huawei.com> <20170109234110.GA10298@bbox> <20170113042444.GE9360@jagdpanzerIV.localdomain> <20170113062343.GA7827@bbox> <20170113063614.GA484@jagdpanzerIV.localdomain> <20170113064719.GA8018@bbox> <20170113070245.GB484@jagdpanzerIV.localdomain> MIME-Version: 1.0 In-Reply-To: <20170113070245.GB484@jagdpanzerIV.localdomain> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-ID: To: Sergey Senozhatsky Cc: zhouxianrong@huawei.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, sergey.senozhatsky@gmail.com, ngupta@vflare.org, Mi.Sophia.Wang@huawei.com, zhouxiyu@huawei.com, weidu.du@huawei.com, zhangshiming5@huawei.com, won.ho.park@huawei.com On Fri, Jan 13, 2017 at 04:02:45PM +0900, Sergey Senozhatsky wrote: > On (01/13/17 15:47), Minchan Kim wrote: > [..] > > > > Could you elaborate a bit? Do you mean this? > > > > > > > > ret = scnprintf(buf, PAGE_SIZE, > > > > "%8llu %8llu %8llu %8lu %8ld %8llu %8lu\n", > > > > orig_size << PAGE_SHIFT, > > > > (u64)atomic64_read(&zram->stats.compr_data_size), > > > > mem_used << PAGE_SHIFT, > > > > zram->limit_pages << PAGE_SHIFT, > > > > max_used << PAGE_SHIFT, > > > > // (u64)atomic64_read(&zram->stats.zero_pages), > > > > (u64)atomic64_read(&zram->stats.same_pages), > > > > pool_stats.pages_compacted); > > > > > > yes, correct. > > > > > > do we need to export it as two different stats (zero_pages and > > > same_pages), if those are basically same thing internally? > > > > So, let summary up. > > > > 1. replace zero_page stat into same page stat in mm_stat > > 2. s/zero_pages/same_pages/Documentation/blockdev/zram.txt > > 3. No need to warn to "cat /sys/block/zram0/mm_stat" user to see zero_pages > > about semantic change > > 1) account zero_page and same_pages in one attr. > > this already is in the patch. > > 2) do not rename zero_pages attr. > > we can't do this so fast, I think. > > > > 3. No need to warn to "cat /sys/block/zram0/mm_stat" user to see zero_pages > > about semantic change > > yes. we just _may_ have more pages (depending on data pattern) which we treat > as "zero" pages internally. this results in lower memory consumption. I don't > think warn users about this change is necessary; they won't be able to do > anything about it anyway. zero_pages stat is pretty much just a fun number to > know. isn't it? > I just wanted to confirm your thought. I hope anyone doesn't is sensitive on that number. ;) Let's replace zero_page stat field in mm_stat. Thanks. -- 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