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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1452C433FE for ; Tue, 8 Nov 2022 00:40:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232953AbiKHAkg (ORCPT ); Mon, 7 Nov 2022 19:40:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233140AbiKHAkX (ORCPT ); Mon, 7 Nov 2022 19:40:23 -0500 Received: from mail-pg1-x52d.google.com (mail-pg1-x52d.google.com [IPv6:2607:f8b0:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BEA202611D for ; Mon, 7 Nov 2022 16:40:20 -0800 (PST) Received: by mail-pg1-x52d.google.com with SMTP id h193so11990709pgc.10 for ; Mon, 07 Nov 2022 16:40:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=OM0r5u0WH+buQLtra84lMSPb6itvSvD0nc8HMAGCciQ=; b=TWamq7EdLsQok6vDR75JzTopHL0ZZBUv5VALE1B1puumyYTXPDCYlR+2gogdv6Rkm2 lugkVLtCa98IEJFVaurvYmUwXAJEojHJv3X8aHMGO4zLnat7Foc8egfpLkd71PLldEHK UyszcgqFuL2kpl+QHO1IrpIdrVIr8ZgPDe9kY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=OM0r5u0WH+buQLtra84lMSPb6itvSvD0nc8HMAGCciQ=; b=v+P4/R94NLF+aMba6l5mbcJFdhLPVFQPH+CWGYAGEHljutvThCyb60kDfSlimuNnax BH7RzJHQW9uhPMec5Qkr2Rrmf70U5lxAJRbeYfauDvaev6qQIsHpwx0Jw/01HoyM94Ti nQvYOQOszCdyNcXv8S52pAb2vRa0iPQxIdVKUL2/rDAsvYlAMYRX2dTaGaAdV46BSktr Rd6ACWQ1p6v8HSQ/am0PyIPi9a4hOTqUwx2UaSCIlI8IjgnFPvZ+Jx23kwYpQP5Vdjh8 A5nsUNLaBhNVL6DzcdbWjegmZy/og7auWEWf8F8uMuiW5lZAbBynIfHPGht4gdMk47gL rKSQ== X-Gm-Message-State: ACrzQf1hYDtvzDzn1zRyOJMTKLiDhSL07WgTj23nKifOxVRkYMCe6nD/ y61oBgzJQuxxeRJe59VKd8ECnlQz6YXSkQ== X-Google-Smtp-Source: AMsMyM6xYGNGchyjy8QrKxApfI8UUYUySm1ARIZSxlctWm/xSgTxWJ7u0ClT72ZMItyHqsIBJBa+GA== X-Received: by 2002:a63:8bc3:0:b0:46f:fa99:7d76 with SMTP id j186-20020a638bc3000000b0046ffa997d76mr30252805pge.134.1667868020231; Mon, 07 Nov 2022 16:40:20 -0800 (PST) Received: from google.com ([240f:75:7537:3187:8d5d:1342:1172:9487]) by smtp.gmail.com with ESMTPSA id a24-20020aa794b8000000b0056cd54ac8a0sm5055970pfl.197.2022.11.07.16.40.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Nov 2022 16:40:19 -0800 (PST) Date: Tue, 8 Nov 2022 09:40:15 +0900 From: Sergey Senozhatsky To: Minchan Kim Cc: Sergey Senozhatsky , Andrew Morton , Nitin Gupta , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCHv4 2/9] zram: Add recompression algorithm sysfs knob Message-ID: References: <20221018045533.2396670-3-senozhatsky@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (22/11/07 11:08), Minchan Kim wrote: [..] > I am thinking like this: > > * Without recomp_algo setup, user can do whatever they want on the fly > > > echo "type=idle threshold=3000 algo=zstd" > recompress > > Later they could do > > echo "type=idle threshold=3000 algo=deflate" > recompress By "without recomp_algo setup" you mean that user doesn't configure anything before `echo XG > zramX/disksize`? Currently algorithm and recomp algorithm need to be selected at the same time - before zram device is initialised, because we use the same code and same approaches: we need to have zcomp back-ends in per-CPU data in zram read/write/recompress. Creating per-CPU zcomps on the fly is probably going to be a little bit intrusive to zram. What I currently have is as follows. A copy paste from my test script: - init device echo "algo=lz4 priority=1" > /sys/block/zram0/recomp_algorithm echo "algo=zstd priority=2" > /sys/block/zram0/recomp_algorithm echo "algo=deflate priority=3" > /sys/block/zram0/recomp_algorithm echo 5G > /sys/block/zram0/disksize Various recompression use cases: - recompress huge pages using all secondary algos in order of priority echo "type=huge" > /sys/block/zram0/recompress - recompress huge pages using zstd only echo "type=huge algo=zstd" > /sys/block/zram0/recompress - recompress all pages using lz4 echo "algo=lz4" > /sys/block/zram0/recompress - recompress idle pages, use all algos in priority order, with threshold echo "type=idle threshold=3000" > /sys/block/zram0/recompress - recompress idle pages, using zstd only, with threshold echo "algo=zstd type=idle threshold=2000" > /sys/block/zram0/recompress