Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758071AbdHYS4I (ORCPT ); Fri, 25 Aug 2017 14:56:08 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:49711 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755792AbdHYS4H (ORCPT ); Fri, 25 Aug 2017 14:56:07 -0400 From: Nick Terrell To: Minchan Kim , Sergey Senozhatsky CC: Sergey Senozhatsky , Andrew Morton , "linux-kernel@vger.kernel.org" , Yann Collet Subject: Re: [PATCH] zram: add zstd to the supported algorithms list Thread-Topic: [PATCH] zram: add zstd to the supported algorithms list Thread-Index: AQHTHV2xXWqWlMVfbUKYI//VGek9A6KU92sA Date: Fri, 25 Aug 2017 18:55:44 +0000 Message-ID: References: <20170824014936.4738-1-sergey.senozhatsky@gmail.com> <20170824043038.GA13922@bgram> <20170824140440.GA5535@tigerII.localdomain> <20170825045036.GA26819@blaptop> In-Reply-To: <20170825045036.GA26819@blaptop> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [2620:10d:c090:200::7:7b0a] x-ms-publictraffictype: Email x-microsoft-exchange-diagnostics: 1;DM5PR15MB1771;20:dfHPL8kc129gktkwX/aq+hWUKdiHmE6zPbfMoazU8bVt9JV6Srz+yospDXDI7U1I9lgPlIX2G7AuiTDnis840qQBS/4NoZCZh2g6z5/h0885mp9knou2PsMlALKdfbxlQG1ge+CrbszsORQKO7g1PgH/oYBkeolkgXlsH4aYPWY= x-ms-exchange-antispam-srfa-diagnostics: SSOS;SSOR; x-forefront-antispam-report: SFV:SKI;SCL:-1;SFV:NSPM;SFS:(10019020)(6009001)(24454002)(76104003)(377454003)(199003)(189002)(68736007)(8936002)(305945005)(53546010)(81166006)(105586002)(25786009)(81156014)(50986999)(7736002)(54356999)(76176999)(83716003)(8676002)(6506006)(53936002)(4326008)(101416001)(2906002)(6486002)(2950100002)(6436002)(77096006)(106356001)(14454004)(33656002)(229853002)(54906002)(86362001)(97736004)(5660300001)(82746002)(2900100001)(478600001)(189998001)(6246003)(39060400002)(6512007)(3280700002)(99286003)(93886005)(102836003)(6116002)(36756003)(3660700001);DIR:OUT;SFP:1102;SCL:1;SRVR:DM5PR15MB1771;H:DM5PR15MB1753.namprd15.prod.outlook.com;FPR:;SPF:None;PTR:InfoNoRecords;A:1;MX:1;LANG:en; x-ms-office365-filtering-correlation-id: 58c51ec3-93e2-4932-966f-08d4ebeae3fa x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:(300000500095)(300135000095)(300000501095)(300135300095)(300000502095)(300135100095)(22001)(2017030254152)(300000503095)(300135400095)(2017052603199)(201703131423075)(201703031133081)(201702281549075)(300000504095)(300135200095)(300000505095)(300135600095)(300000506095)(300135500095);SRVR:DM5PR15MB1771; x-ms-traffictypediagnostic: DM5PR15MB1771: x-exchange-antispam-report-test: UriScan:; x-microsoft-antispam-prvs: x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(100000700101)(100105000095)(100000701101)(100105300095)(100000702101)(100105100095)(6040450)(601004)(2401047)(5005006)(8121501046)(10201501046)(93006095)(93001095)(100000703101)(100105400095)(3002001)(6041248)(20161123558100)(20161123562025)(20161123560025)(201703131423075)(201702281528075)(201703061421075)(201703061406153)(20161123564025)(20161123555025)(6072148)(201708071742011)(100000704101)(100105200095)(100000705101)(100105500095);SRVR:DM5PR15MB1771;BCL:0;PCL:0;RULEID:(100000800101)(100110000095)(100000801101)(100110300095)(100000802101)(100110100095)(100000803101)(100110400095)(100000804101)(100110200095)(100000805101)(100110500095);SRVR:DM5PR15MB1771; x-forefront-prvs: 041032FF37 spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="utf-8" Content-ID: <6DB9B296CEC8A2419DE7F5CD098C039B@namprd15.prod.outlook.com> MIME-Version: 1.0 X-MS-Exchange-CrossTenant-originalarrivaltime: 25 Aug 2017 18:55:44.4088 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM5PR15MB1771 X-OriginatorOrg: fb.com X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-08-25_05:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id v7PIuDIh018269 Content-Length: 727 Lines: 19 On 8/24/17, 9:51 PM, "Minchan Kim" wrote: >Off-topic: > >In all ways, zstd beats deflate. Nick, Right? Yeah. Since all LZ compression algorithms are heuristics, there are some rare cases where zlib beats zstd in compression ratio by a bit, but never speed. In all cases where we've deployed zstd, we've seen aggregate compression ratio improvements over zlib, and expect the same here. >With zstd, I doubt we should show "deflate" to user. Many options just >make user confused. >The inflate have been there for representing high comp ratio but slower >speed. However, zstd is better unconditionally compared to deflate >so how about replacing deflate with zstd? > >Sergey, what do you think about it?