From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D36E1C2D0D2 for ; Fri, 20 Dec 2019 06:04:20 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6D91E24684 for ; Fri, 20 Dec 2019 06:04:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="PhTe8eSZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6D91E24684 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id D95D88E018D; Fri, 20 Dec 2019 01:04:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D45BB8E0184; Fri, 20 Dec 2019 01:04:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C34CB8E018D; Fri, 20 Dec 2019 01:04:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0237.hostedemail.com [216.40.44.237]) by kanga.kvack.org (Postfix) with ESMTP id ACDA08E0184 for ; Fri, 20 Dec 2019 01:04:19 -0500 (EST) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id 29CBB8249980 for ; Fri, 20 Dec 2019 06:04:19 +0000 (UTC) X-FDA: 76284479838.06.town90_7cf4167afc921 X-HE-Tag: town90_7cf4167afc921 X-Filterd-Recvd-Size: 3696 Received: from mail-lj1-f195.google.com (mail-lj1-f195.google.com [209.85.208.195]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Fri, 20 Dec 2019 06:04:18 +0000 (UTC) Received: by mail-lj1-f195.google.com with SMTP id e28so8752238ljo.9 for ; Thu, 19 Dec 2019 22:04:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=TnPyTr2iiNHnW0FS9YnHgx6tK9jG9pl7XCuokVZaafI=; b=PhTe8eSZM1CRDjHBFlNxQ5pvj1zgzFLNdRhHcC2Lp2XM1qd6wU3s0RWNTRZ1YN/AYu VXxyw8EzVnqlngZZuCsT7OS0cWhH6f2bwh/+61kgQ61FpQoYciZLc44V6zvFpz/d7byy CAQygGhDFRvLU6c1CCHW+oCu3PykihSZt8LF42wrm26Bsgx/47xwlonix+L8Ye+XhngK tPR1Gmhee2TnHDeDlMJGayfha+U8vZkBymqSd0qk4PeR2yE+jEBRTesDAMcyurPIMEVm G4WY33Ewvn/sNEMyCDmH5F9vZKC/9HaYCGJ0px7fV5So1GXVHsKGqu2KLCqjwC60Ttql SIbw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=TnPyTr2iiNHnW0FS9YnHgx6tK9jG9pl7XCuokVZaafI=; b=YBs8fuzRXqabaqRXd2pZvup1EVMqzts1FptWQJeyLuDnDNaNb6SHFySLm46eC4/iEv 7B1Bhe0vyUKPtWTlTeeGnCyHaQ82Vp3IE4XSgSKehS/12dClTm+FbOBGz0dC5GVD3+5H wpZFyTg2r5MLdmAIusRl3F106CtwuhSchK4AvNS1E4ObeDmn0LEjflZtqPQ/UnrdBIN/ LDkQkPFhKIoM/tJd8AXt8S7HCaOd1xdpAbqHpwlT+pbkVeYakc5vfrIQU1ppwE/DQjJ3 5E5n4lCgc0Z/t1qBiMGuf0iKlJDAdkc42YrjL7e1ZkvmEJU0q5EyguYRlev4SkJ1o1UZ bh7g== X-Gm-Message-State: APjAAAXKauq5HGegkbeELI9+t63tbG2922rex7jjwQbGB8LAdPLd98fZ d2n46Me08uHB7LG0TRW9og4EqOKXnL7GC6oO6vc= X-Google-Smtp-Source: APXvYqyznCQjAejJGQyUMTiTnBung9lMO1/L3p896yj6PoSLgSFibyAZeOlUUZ0rSGDMIboCKjKbZnJNqx76W4BHskg= X-Received: by 2002:a2e:8015:: with SMTP id j21mr8689791ljg.172.1576821857009; Thu, 19 Dec 2019 22:04:17 -0800 (PST) MIME-Version: 1.0 References: <20191219151928.ad4ccf732b64b7f8a26116db@gmail.com> <20191220031357.GA39061@google.com> In-Reply-To: <20191220031357.GA39061@google.com> From: Vitaly Wool Date: Fri, 20 Dec 2019 07:04:05 +0100 Message-ID: Subject: Re: [PATCHv2 0/3] Allow ZRAM to use any zpool-compatible backend To: Minchan Kim Cc: Linux-MM , Andrew Morton , Dan Streetman , Sergey Senozhatsky , LKML , Vlastimil Babka , Shakeel Butt , Henry Burns , "Theodore Ts'o" Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Dec 20, 2019 at 4:14 AM Minchan Kim wrote: > Look https://lkml.org/lkml/2019/10/29/1169 > > z3fold read is 15% faster *only* when when compression ratio is bad below 50% > since zsmalloc involves copy operation if the object is located in the > boundary of discrete pages. It's never popular workload. > Even, once write is involved(write-only, mixed read-write), z3fold is always > slow. Think about that swap-in could cause swap out in the field because devices > are usually under memory pressure. Also, look at the memory usage. > zsmalloc saves bigger memory for all of compression ratios. Yes I remember that. Since your measurements were done on "an x86" without providing any detail on the actual platform used, they are as good as none. ~Vitaly